annex d terms of reference site preparation, construction… · 2016. 4. 29. · site preparation,...

ANNEX D

TERMS OF REFERENCE

SITE PREPARATION, CONSTRUCTION, INSTALLATION SUPPORT AND INITIAL TESTING AT IMS INFRASOUND STATION IS20 , GALAPAGOS ISLANDS, ECUADOR

Terms of Reference for Site Preparation, Construction, Installation Support and Initial Testing at IMS Infrasound Station IS20, Galapagos Islands, Ecuador

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Table of Contents

1 SUMMARY........................................................................................................................................................ 1-3

2 SCOPE OF WORK ........................................................................................................................................... 2-4

3 GENERAL DESCRIPTION OF THE STATION ........................................................................................ 3-5

4 WORK TASK 1: SITE PREPARATION AND CONSTRUCTION OF THE STATION ..................... 4-5

4.1 GENERAL OBLIGATIONS ................................................................................................................................. 4-5 4.2 CONSTRUCTION OF THE ARRAY ELEMENTS............................................................................................... 4-6 4.2.1 Equipment Vaults 4-7 4.2.2 Wind-noise-reduction systems 4-7 4.2.3 Power Supplies 4-7 4.2.4 Communications Cables 4-8 4.2.5 Lightning Protection 4-9 4.2.6 Miscellaneous 4-9 4.3 CONSTRUCTION OF CENTRAL RECORDING FACILITY ............................................................................. 4-9 4.3.1 Building 4-9 4.3.2 Power Supply 4-9 4.3.3 Lightning Protection 4-10 4.3.4 Mounting for Equipment 4-10 4.3.5 Communications cables 4-10 4.3.6 VSAT Dish 4-10 4.3.7 GCI Facility 4-11 4.3.8 Security Fencing 4-11 4.3.9 Miscellaneous 4-11

5 WORK TASK 2: INSTALLATION SUPPORT ......................................................................................... 5-11

5.1 ASSISTANCE OF EQUIPMENT, TRANSPORTATION AND STORAGE. ............................................................................ 5-11 5.2 FIELD ASSISTANCE ............................................................................................................................................... 5-12 5.3 STATION VEHICLE ................................................................................................................................................ 5-12

6 WORK TASK 3: INITIAL TESTING ......................................................................................................... 6-12

7 STATION INSPECTION ............................................................................................................................... 7-13

8 DOCUMENTATION, PLANS AND REPORTS ........................................................................................ 8-13

8.1 PLANS AND REPORTS ......................................................................................................................................... 8-13 8.1.1 Station Design Report/ Revised Station Design Report 8-14 8.1.2 Site Preparation and Civil Works Plan and Time Schedule 8-14 8.1.3 WORK TASK 1 Progress Reports/Revised WORK TASK 1 Progress Reports 8-15 8.1.4 Final/Revised Final Report 8-15 8.1.5 Initial Testing Monthly Reports 8-16 8.2 ACCEPTANCE OF WORK ................................................................................................................................ 8-16

9 LIST OF ATTACHMENTS........................................................................................................................... 9-16


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1 SUMMARY

(a) The Provisional Technical Secretariat of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (the “Commission”) intends to establish the IMS infrasound station IS20 in Galapagos Islands, Ecuador (the “Station”). The Station has been designated as facility of the infrasound network of the Comprehensive Nuclear-Test-Ban Treaty and identified for installation by the Commission (the “Project”).

(b) The Commission desires to engage a contractor (the “Contractor”) to provide goods, services and works for the site preparation, construction, installation support and the initial testing at the Station in accordance with these Terms of Reference (the “ToR”). The Contractor shall carry out the site preparation, civil works, and supply and install Contractor’s equipment (the “Contractor’s Equipment”) in order to prepare the Station to host the infrasound equipment (the “Commission’s Equipment”). The Contractor will be required as well to provide support to the Commission, the Commission’s equipment supplier(s) and the Commission’s designated Station Operator Instituto Oceanográfico de la Armada (INOCAR) (the “Station Operator”) during installation of the Commission’s Equipment. The Commission and the Commission’s equipment supplier(s) will provide, install and test the Commission’s Equipment.

(c) The Commission intends to establish a Contract for “Site Preparation, Construction, Installation Support and Initial Testing at IMS Station IS20, Galapagos, Ecuador” (hereinafter referred to as the “Work” and/or “Services”) in accordance with these ToR. These ToR define the technical framework of all related activities to be performed during the delivery of Services and contains all technical requirements for the activities which shall be carried out by the Contractor.

(d) The Contractor shall carry out the Work in accordance with these ToR and in the most cost-effective manner possible. For all work tasks, the Contractor must inform the Commission of the appropriate and current points of contact, including contacts for: 1) technical matters, 2) logistics matters and 3) commercial matters. If these points of contact change during any phase of the Work Tasks, the Contractor must inform the Commission immediately in writing.

(e) The Station is located inside the Galapagos National Park. The Contractor shall:

(i) demonstrate very good knowledge of the environmental laws and regulations in force in the Galapagos National Park and provide advice on related issues when and as required by the Commission;

(ii) demonstrate experience in liaising with Direction of the Galapagos National Park (“Dirección Parque Nacional Galápagos”, hereinafter referred to as the “DPNG”) and obtain licenses and permits necessary to perform the work described in this ToR.


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2 SCOPE OF WORK

The Work will be divided into 3 (three ) Work Tasks in accordance with the requirements of these

ToR as follows:

No. Work Task

1. Site Preparation and Construction of the Station

2. Installation Support

3. Initial Testing (including optional extension)

The Work Tasks include the below mentioned tasks to be completed by the Contractor and in accordance with the requirements as further described in Sections 4 to 6 of these ToR:

(a) Fulfillment of all general obligations;

(b) Provision of the Central Recording Facility (CRF) with a reliable source of power by connecting the CRF to the local AC mains grid and installing a back-up AC power supply, consisting of an AC generator;

(c) Provision and construction of a building to house infrasound recording and data transmission equipment at the CRF;

(d) Provision and installation of surface electrical cables for supply of AC power from the CRF to the array elements;

(e) Provision and installation of surface fiber optical cables for transmission of data from the CRF to the infrasound array elements;

(f) Provision and installation of concrete bases and lightning protection systems for pre-fabricated equipment vaults at each array element;

(g) Preparation of the terrain for the installation of the wind-noise-reduction system (WNRS) at each array element;

(h) Transport of the Commission’s equipment from the port of entry in Galapagos to the Station CRF and array elements;

(i) Provision of support services to the Commission and the Commission’s Supplier(s) during the entire installation and initial testing time period.

(j) Provision of support services to the Station Operator including the provision of a station car and of station operating costs during the entire installation and initial testing time period.

(k) All other works described in Sections 4 to 6.


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3 GENERAL DESCRIPTION OF THE STATION

The Station will be installed in the center of Santa Cruz Island of Galapagos archipelago within the premises of the Galapagos National Park, approximately 17 km North of the Puerto Ayora town about 400 m from the main road as set out in the below Figure 1 of these ToR. The Station shall include eight infrasound array elements, H1 through H8. The array shall have a shape of two irregular interlocked quadrilaterals, the first one with an aperture of about 1.4 kilometers, and the second one with an aperture of about 400 meters as set out in Figure 2 of these ToR. The coordinates of the array elements are listed below in the Table 1.

At each array element a pre-fabricated equipment vault provided by the Commission will comprise a power box (including AC/DC converter), a wind-noise-reduction system, two microbarometers, a data acquisition unit, a GPS antenna, and a fibre optics communications modem. All these equipment will be provided by the Commission.

Each array element will transmit continuous data by surface single-mode optical fiber communications cable to the CRF building. The coordinates of the proposed CRF location can be found in the Table 1. Equipment provided by the Commission will be installed at the CRF to format and transmit data to the International Data Center (the “IDC”) in Vienna through the Global Communication Infrastructure (GCI) and also control various functions connected with authentication, command and control and system calibration.

Local AC mains power will be used to operate the Station. The power supply system will also include an AC generator, which will be installed at the CRF, as a back-up autonomous power supply system. The array elements will be powered from the CRF via surface power cables. A preliminary electrical diagram of IS20 power supply system is shown in Attachment II to these ToR.

The back-up batteries at the array elements to maintain the element operational in case of AC power failure should have sufficient reserve capacity to maintain array elements operational for 5 days. The system’s diesel fuel reservoir should have sufficient capacity to provide power for at least 20 (twenty) days without refueling.

4 WORK TASK 1: SITE PREPARATION AND CONSTRUCTION OF THE STATION

4.1 GENERAL OBLIGATIONS

(a) The Contractor shall complete all preparation and construction works at the site, as descrtibed in the ToR, prior to the installation of the Station’s equipment by the Commission and/or the Commission’s Equipment Supplier.

(b) The Contractor shall ensure that all Work Tasks are performed in compliance with any national, municipal or local regulations, laws, building codes, licensing or permitting requirements related to the implementation of the Work Tasks. The Contractor shall obtain licenses, permits or authorizations needed to carry out the Work under this Project. The Contractor shall:

(i) transport the Commission’s Equipment from the port of entry in Galapagos Islands, Ecuador;


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(ii) store the Commission’s Equipment during the contruction phase for a period of up to 3 (three) months with optional extension for additional 3 (three) months;

(iii) insure the Commission’s Equipment during the construction phase for a period of up to 3 (three) months with optional extension for additional 3 (three) months.

(c) The Contractor shall submit plans and reports as specified in Section 8 of these ToR.

(d) The Contractor shall submit a work schedule for the site preparation and the completion of all civil works in English to the Commission. The Commission reserves the right to monitor/inspect field operations at an agreed-upon time by sending the Commission’s representatives to the Stations.

(e) The Contractor shall ensure that the Commission’s and the Commission’s Equipment Supplier’s and/or Commission’s contractor’s representatives are granted access to the Station at any agreed-on time to monitor field operations and progress of the work.

(f) The Commission and/or the Commission’s Equipment Supplier will be responsible for the supply and for the installation of all Stations’ Equipment for the Station’s array elements and the CRF. This includes the electronic and communications equipment, pre-fabricated wind-noise-reduction systems and the pre-fabricated equipment vaults, meteorological equipment, GPS antennas and power supplies for remote array elements.

(g) The Commission will be responsible for delivering the Station’s Equipment to the port of entry in Galapagos Islands, Ecuador.

(h) The Commission and/or the Commission’s Equipment Supplier will be responsible for the supply and installation of the communication and data acquisition equipment for the CRF and the GCI facility. The Commission will supply equipment spare parts as required for efficient operation and maintenance of the Stations.

4.2 CONSTRUCTION OF THE ARRAY ELEMENTS

The location of the IS20 array elements is shown in Figures 1 and 2. The proposed coordinates for each array element are listed in Table 1. The Commission will indicate to the Contractor the exact location of each vault prior to the construction phase.

Table 1. Proposed Coordinates# for IS20 Galapagos Islands, Ecuador

Site Latitude Longitude

Central Recording Facility 0.60417°S 0°36'15"S 90.37028°W 90°22'13"W

Array element H1 0.59959°S 0°35'59''S 90.37978°W 90°22'47''W






Array element H7* 0.60944°S 0°36'34''S 90.38403°W 90°23'03''W

Array element H8 0.59862°S 0°35'55''S 90.39036°W 90°23'25''W #WGS84 Geoid


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4.2.1 Equipment Vaults

At each site of the array the Contractor shall install a waterproof, insulated pre-fabricated equipment vault, supplied by the Commission.

The Commission shall provide the vaults, but the Contractor shall provide adequate personnel to transport the vaults to the sites and install the vaults at each array element, under the direct orientation of representatives from the Commission or a Commission’s Equipment supplier.

The vault details are shown in Figure 6.

The equipment vaults at the array elements H1 to H8 shall be installed above the ground. The Contractor will provide the reinforced concrete base for the equipment vault at each array element. The concrete base shall be 1.5 x 1.5 x 0.3 m, with a bottom at 0.3 m depth.

The pre-fabricated equiment vaults will be shipped to the site prior to the Station installation.

Each vault will house the power supply, back-up batteries, two microbarometers, the digitizer and the communication equipment.

A meteorological station, consisting of a wind sensor and a temperature sensor, will be installed at the array element H1. The sensors will be mounted on a meteorological mast. The Contractor shall install the mast, 76mm diameter steel pipe 2-m high, mounted on a concrete base within 3 meters of the vault at the central array element H1. The Contractor shall provide a watertight, buried or surface stainless 76-mm diameter cable conduit between the base of the mast and the the vault. The meteorological sensor cable will be routed inside the mast and through this conduit to the inside of the vault. The mast should have an opening (30 mm in diameter) at 90 cm height for the temperature sensor cable.

The Commission will supply the meteorological sensors, cables and mounting fixtures. A sample drawing of the meteorological mast is shown in the Figure 11.

4.2.2 Wind-noise-reduction systems

18-m diameter wind-noise-reduction systems (WNRS) with 96 inlet ports will be installed at IS20 array elements. Illustrations of WNRS are given in Figures 3 and 4.

The Commission will provide all material for the pipe arrays but the Contractor shall provide adequate personnel to install the WNRS at each array element, under the direct orientation of representatives from the Commission or a Commission’s Equipment Supplier.

The WNRS is made of 15 mm diameter rubber hoses. The pipes of the WNRS will be placed on the surface.

The work required to install the WNRS can be done in two weeks by two plumbers.

4.2.3 Power Supplies

Alternating current (AC) power will be supplied to the infrasound array elements from the CRF via surface electrical cables. The Contractor shall define the most economical and efficient route for running the cables from the CRF to the remote sites. A suggested scheme of AC distribution is shown in the Attachment II.

The power supply system shall be based on local mains with an AC generator as a back-up power supply. The generator shall have a fuel tank for at least twenty days of operation. The estimated minimum capacity of the generator is 5 kW. The power supply system shall include an automatic switch batween mains input and back-up generator. The generator shall start automatically when


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the mains power is off for 5 minutes and stop running 10 minutes after the mains power is re-connected.

The Contractor shall provide, install and test electrical cables between the CRF and the remote elements for supply of AC power to the sites. The cables shall be selected in accordance with the estimated load and installed in the way to comply with local electrical wiring regulations. These cables must be suitable for direct surface installation and shall be armoured and covered with a hard polyethylene jacket for protection from insect and rodent attack. The cables must have sufficient current carrying capacity to ensure that the supply voltage at the array elements is maintained under peak load conditions. The average electrical current requirement at the infrasound array elements H1 to H8 is estimated at 18 W. The charging load for the backup battery is additional and can be estimated at 300 W per element.

An AC to regulated DC power supply will be used at each remote site to provide the operating DC voltage for the electronic equipment and to maintain charge on the backup battery. These power supplies shall be provided by the Commission.

At each remote site the AC power cable should be terminated in a suitable junction box in the equipment vault. Short circuit protection (current limit), surge arrestors and auto-resettable residial switches shall be provided by the Commission for each array element.

The backup batteries at each array element must be capable of ensuring continuous, autonomous operation of all associated instrumentation and communications equipment for a period of 5 days in the event of a loss of power from the CRF. Contractor shall procure and install back-up batteries, as specified below:

Type: Valve-regulated, lead acid, manufactured with gelled electrolyte or AGM Voltage: 2 volts Bank assembly: 6 cells / 12 V Nominal Capacity of battery bank: 240 Ah@12V (2880 Wh) Terminal: 3/8”flag terminal or T terminal (M8) Environment: +10° to + 60°C Quantity: 9 battery banks (eight for array elements H1 to H8 and one spare)

4.2.4 Communications Cables

Intra-array communications via single-mode optical fibre shall be used at the Stations. Separate surface single-mode fibre optic communications cables are required between each remote site and the CRF. Each cable should contain at least six (6) optical fibres to provide spare circuits in case of failure in a circuit. The cable should be led into the equipment vault and terminated in a waterproof splice box. The box shall have 3 pairs of SC/PC receptacles on the front panel.

The fiber optic cables at the CRF shall be terminated inside the CRF building in a termination box with SC/PC receptacles on the front panel. The receptacles shall be clearly identified (remote site name, pair and fiber number). The Commission shall provide ‘pigtail’ single-mode fiber optic cables with SC/PC connectors installed to interface to the fibre optic modems in the equipment vaults and at the CRF.

The details of the communication system preliminary design can be found in the Attachment III. The Contractor can combine communication and power lines using specialized fiber optic cables with copper wires. Both communication and power lines must be layed out and protected in accordance with national and local regulations.


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4.2.5 Lightning Protection

A robust and efficient lightning protection system meeting the requirements to the Lightning Protection System (LPS) Class 2, according to IEC 62305 international standard and Commission’s internal standard (Attachment IV), shall be provided and installed by the Contractor at each array element in compliance with local rules and regulations. All equipment shall be connected to this system to minimize damage from lightning strike and to eliminate ground loops. A connection point to the grounding system must be provided for the Commission’s equipment located at the array element.

The grounding system shall be based on copper strips with grounding rods. All equipment in the vault should be connected to the common grounding point. The pipe array shall be connected to the grounding system. Details of the lightning protection system are shown in Attachment IV.

4.2.6 Miscellaneous

The Contractor shall investigate the need for miscellaneous construction works at the array elements and, if required, fully specify the works to be done to the Commission and obtain the Commission’s approval before proceeding with the works.

4.3 CONSTRUCTION OF CENTRAL RECORDING FACILITY

The Central Recording Facility (the “CRF”) shall be built in the point with the coordinates shown in the Table 1, 200 m north of the Santa Cruz Highway, approximately 25 km along the road from Puerto Ayora. It provides the interface between the array elements and the GCI for transmission of data to the International Data Centre in Vienna. The CRF building should have sufficient space to accommodate the equipment of the Station, which will be mounted in a standard 19” 42U equipment rack, provided by the Commission.

The CRF area shall be 40 x 40 m, cleared from vegetation, in order to provide access to the building and sight to the sky for GCI antenna. Suggested layout of the CRF is shown in the Figure 10.

4.3.1 Building

The Contractor shall construct a building at the CRF to house the GCI equipment, the processing equipment of the Station and the backup power supply. The entrance door and windows must be fitted with security grills/screens to prevent unauthorized access. The building should have adequate ventilation and automatic air-conditioning system to ensure proper functionality of the CRF equipment. The Contractor shall provide also the building’s water supply and install a sewage tank according to local rules and regulations. The temperature inside the building shall not be above 25° C. A possible building (photo and plan) is shown in the Figures 8 and 9.

4.3.2 Power Supply

The Contractor shall provide connection to the mains AC electrical power at the CRF, including step-down transformer 13/0.4 kV and an AC generator as a back-up power supply. A preliminary calculation show that 5 kW 230 VAC single phase power supply (generator) shall be sufficient for the Station equipment, however, 3-phase 380 VAC power supply can be considered as well. All the Commission equipment is powered by single-phase 230 VAC. The details of preliminary power supply design are shown in the Attachment II.


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The CRF equipment shall consume about 300 W, total CRF load can be estimated at 1 kW (including air condition unit and lighting).

The building shall be equipped by at least six (6) fused outlets of European type (i.e. Siemens or equivalent) for connection of mains operated equipment.

The Commission and/or the Commission’s Equipment Supplier will supply an Uninterruptable Power Supply (UPS) to maintain the Station operation during short-term interruptions to the mains power.

4.3.3 Lightning Protection

A robust and efficient lightning protection system meeting the requirements to the Lightning Protection System (LPS) Class 2, according to IEC 62305 international standard and Commission’s internal standard (Attachment IV), shall be provided and installed by the Contractor at the CRF. All equipment shall be connected to this system to minimize damage from lightning strike and to eliminate ground loops. A connection point to the grounding system must be provided for the Commission’s equipment inside the equipment room of the CRF.

4.3.4 Mounting for Equipment

The Commision shall supply a 42U standard lockable 19” equipment rack for the Commission’s Equipment.

The Contractor shall provide and install the following furniture for the CRF building:

- Work desks with drawers: 2 sets;

- Office chairs: 4 (four);

- Industrial shelves system for store room;

- Bookshelves equipment room: 2 sets;

- A color laser or inkjet printer, 1200 x 1200 dpi, including scanning capability, with USB 2.0 and/or Ethernet and 2 spare toners and white paper (300 pages);

- A cabinet for equipment room;

- A CO2 fire extinguisher(s) with a total capacity of at least 5 kg.

4.3.5 Communications cables

The communications fiber optic cables shall be led into the building. The Contractor will provide the fibro-optic interconnexion box with SC/PC fibro optic receptacles. The receptacles shall be clearly identified (remote site name, pair and fiber number).

4.3.6 VSAT Dish

A dish antenna will be used to transmit data to the IDC in Vienna via the GCI.

The Contractor shall build an appropriate base for a GCI satellite antenna. Specifications for the antenna base, recommendations for the construction works and information about the GCI equipment are included in Attachment V to the ToR.


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The dish must be located in an area with an unobstructed view to the satellite (azimuth 89.7°, elevation 13.2°), and free from any electrical interference.

Installation and testing of the satellite dish and GCI indoor unit will be carried out by the Commission’s GCI contractor.

4.3.7 GCI Facility

The Commission and/or the Commission’s Equipment Supplier shall install and make connection to the GCI.

4.3.8 Security Fencing

The CRF building and the VSAT satellite dishes must be surrounded with a security fence to prevent unauthorized access.

4.3.9 Miscellaneous

The Contractor shall investigate the need for miscellaneous construction works at the CRF and, if required, fully specify the works to be done to the Commission and obtain the Commission’s approval before proceeding with the works.

5 WORK TASK 2: INSTALLATION SUPPORT

5.1 ASSISTANCE OF EQUIPMENT, TRANSPORTATION AND STORAGE

The Contractor shall: (a) Upon delivery of the Commission’s Equipment to the point of entry into the country by

the Commission’s Equipment Supplier, provide all necessary assistance for customs clearance of the Commission’s Equipment;

(b) Receive all the Commission’s Equipment at the port of entry in Galapagos, Ecuador and transport the Commission’s equipment to the Station sites (CRF and array element, when necessary). The Commission’s Equipment will include pre-fabricated wind noise reducing systems, pre-fabricated equipment vaults, power supply, communication, data acquisition equipment, tools and consumables with a total estimated volume of about 30 m3 and weight of 12 t. The GCI equipment is not included in this estimation as well as not included under Commission’s Equipment under this Contract;

(c) Provide insurance for the Commission’s Equipment from the time of receipt at the point of entry to Galapagos Islands, Ecuador until the acceptance of the Final Report. The total value for the equipment is currently estimated to be about US$ 800,000;

(d) Provide adequate storage of the Commission’s Equipment from the time of its delivery to at the point of entry to Galapagos Islands, Ecuador until the installation at the Station.

The Commission will be responsible for the shipment of the Commission’s equipment to the port of entry in Galapagos, Ecuador.


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5.2 FIELD ASSISTANCE

The Contractor shall provide up to 10 technical specialized staff on site to assist in the installation of all Station’s equipment by the Commission and/or the Commission’s equipment supplier(s).

The Contractor shall provide the above mentioned staff to assemble the equipment vaults and the wind-noise-reducing system at each array element under the orientation of staff from the Commission/Commission’s equipment supplier. The Contractor’s employees must be knowledgeable about all relevant aspects of the site preparation work. Such employees shall assist with the connection of the Commission’s equipment to the power supply system, the communications systems and other site infrastructure. They will also assist with installing and testing all the Station’s equipment and apparatus.

The Contractor may be requested to provide inland on-site transportation required by the Commission representative and/or the Commission’s Equipment Supplier and generally facilitate the work done by the Commission and/or the Commission equipment supplier during the initial installation phase.

5.3 STATION VEHICLE

The Contractor shall procure and deliver to the CRF location a vehicle to be used for the station installation, certification and operation.

The specifications of the vehicle are listed in the Attachment VI to the ToR.

The vehicle shall be registered to the Station Operator (INOCAR) in accordance with national and local regulations. All the necessary registration fees, as well as 1-year car insurance, shall be provided by the Contractor. The Contractor shall provide a protected parking of the vehicle until the installation of the Station is finished. The protected parking should not exceed 9 months after the completion of Work Task 1

After the completion of the Services under the Contract, the vehicle shall be transferred to the Station Operator, identified by the Commission.

6 WORK TASK 3: INITIAL TESTING

The Initial Testing (IT) period starts when the Commission’s Equipment is installed and tested at the Station by the Commission. The duration of Initial Testing is 6 (six) months and can be extended for up to 6 (six) months until the Post-Certification Activities Contract with the Station Operator is signed. The Contractor shall designate up to 2 staff as the Station Caretakers. Once a week the Caretaker(s) shall visit the Station CRF and array elements and check the following:

physical security: evidence of tampering external to the facility, evidence of tampering to all external components (e.g., the lightning protection system, GCI satellite dish, enclosures, etc.);


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batteries status: verify the voltage and the overall condition of the batteries at the array elements;

signs of deterioration of the infrastructure (e.g. leaking roof, door seal, presence of water inside the enclosures of the array elements);

routine housekeeping tasks such as cleaning the CRF.

At the end of each visit the caretaker will make all required log entries, showing the date and the purpose of the visit, his observations and all required maintenance actions. The log file will be sent to the Commission at least once a month or anytime it is requested by the Commission. On monthly basis, the caretaker will clear the access paths to the array elements, inspect and clean the equipment at the array elements, cut the weeds and clean the yard of the CRF, check the infrastructure, lubricate the padlocks and hitches, clean the GPS antennas, clean and paint the corroded parts of the installation. The Contractor shall provide all the necessary consumables and tools to ensure reliable and continuous operation and maintenance of the Station infrastructure during the time of Initial Testing, including those not explicitly mentioned in these ToR. It shall also cover for all Station operating cost including electricity costs and fuel refilling for the vehicle and other Contractor’s Equipment during the Initial Testing.

7 STATION INSPECTION

The Commission will carry out inspections any time during the performance of the Work. Specifically, the Commission will visit the sites after the completion of the Work to be sure that the sites are ready for the installation of the Commission’s Equipment. It is expected that two Commission’s representatives will take part in the inspections. The Contractor will facilitate the work of the Commission’s representatives by providing on-site transportation and other logistical arrangements as required.

8 DOCUMENTATION, PLANS AND REPORTS

The Contractor shall ensure that all the manuals and technical specifications received for the Station’s equipment, including manuals for the operation and maintenance will be kept in a safe location at the Station.

8.1 PLANS AND REPORTS

Unless otherwise agreed with the Commission, reports, plans and any other documentation shall be submitted as described in this Section. All reports and communications shall be in English and reports shall be submitted in original hard copy and two copies as well as in electronic version. The Commission has to review and accept these reports in written form in order to consider Work Tasks completed. In the event that the Commission is not satisfied with the submitted report and/or plan, it can instruct the Contractor to carry out remedial action pursuant to the latter’s commitment under this Contract. The Contractor shall remedy the defects and re-submit the Revised Report(s) within the timelines set out in the sections below.


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The Contractor shall submit to the Commission: No. Plans and Reports

1. Station Design Report/ Revised Station Design Report

2. Site Preparation and Civil Works Plan and Time Schedule /

Revised Site Preparation and Civil Works Plan and Time Schedule

3. Work Task 1 Progress Report 1 / Revised Work Task 1 Progress Report 1

4. Work Task 1 Progress Report 2 / Revised Work Task 1 Progress Report 2

5. Final Report/ Revised Final Report

6. Initial Testing Monthly Reports and, if required by the Commission

Additional Testing Monthly Reports for Optional Extension

8.1.1 Station Design Report/Revised Station Design Report

The Station’s Design Report shall be prepared by the Contractor and submitted to the Commission not later than 2 months after the Contract is signed, providing all recommendations, designs, specifications and drawings.

In particular, the Contractor shall submit a detailed design plan for the Station, including engineering plans of the remote elements and CRF, communication system plans and power distribution system diagrams. These plans must be approved by the Commission before construction of any part of the Station.

The Commission shall review the Station’s Design Report within 2 weeks after it’s reception.

Any change of the plan/coordinates must be approved by the Commission prior to the construction of the CRF and array elements.

If the Commission, after review of the Station Design Report requires further information and/or remedial action is necessary, the Commission will instruct the Contractor to provide such additional information and/or a more detailed description of the remedial action taken. The Contractor shall submit such additional information in the form of the Revised Station Design Report within 2 (two) weeks of the Commission’s instruction.

8.1.2 Site Preparation and Civil Works Plan and Time Schedule/ Revised Site Preparation and Civil

Works Plan and Time Schedule

The Contractor shall submit a final schedule for site preparation and for the completion of all preparation and construction works within 30 days of the approval of the Stations’ Design Report /Revised Station’s Design Report by the Commission.

If the Commission, after review of the Site Preparation and Civil Works Plan and Time Schedule requires further information and/or remedial action is necessary, the Commission will instruct the Contractor to provide such additional information and/or a more detailed description of the remedial action taken. The Contractor shall submit such additional information in the form of the Revised Site Preparation and Civil Works Plan and Time Schedule within 2 (two) weeks of the Commission’s instruction.


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8.1.3 WORK TASK 1 Progress Reports/Revised WORK TASK 1 Progress Reports

The Contractor shall prepare and submit to the Commission 2 (two) Progress Reports as follows:

1. The Work Task 1 Progress Report 1 shall be submitted within 2 (two) weeks upon conclusion of the CRF building and ligthning protection, cabling works (power and communication) to the CRF and the array elements and purchase of the vehicle;

2. The Work Task 1 Progress Report 2 shall be submitted within 4 (four) weeks after completion of Work Tasks 1 and 2 referred to in Sections 4 and 5.

The Work Task 1 Progress Report 1 shall contain:

(a) detailed decsription of the performed works;

(b) include revelent photographs with descriptive captions which would help to assess the degree of completion of the works;

(c) include the Procurement Interim Report/ Revised Procurement Interim Report, which shall include photos and item lists for Equipment and the Vehicle procured for the Station. The report shall also give evidence of how the procured equipment and parts are stored. The Commission will review the report and might comment and/or request missing information. In case the Commission requests changes and/or additional information, the Contractor shall make all requested modifications/provide the additional information and submit a Revised Interim Procurement Report within one month from the Commission’s written request.

The Work Task 1 Progress Report 2 shall contain:

(a) detailed decsription of the performed works;

(b) include revelent photographs with descriptive captions which would help to assess the degree of completion of the works;

If the Commission comes to the conclusion that some remedial actions with respect to the Work are required, the Commission will instruct the Contractor to carry out such remedial actions without delay. If the Commission, after the review of the Work Task Progress Report 1 or 2, requires further information and/or more detailed description of remedial actions taken, the Commission will instruct the Contractor to revise the Report to include such additional information and/or a more detailed description of the remedial actions, and submit Revised Work Task 1 Progress Report(s) 1 and/or 2 to the Commission within 2 (two) weeks of the instruction for review and acceptance.

8.1.4 Final/Revised Final Report

Within 4 (four) weeks after completion of all tasks referred to in Sections 4, 5 and 6, the Contractor shall prepare and submit to the Commission a Final Report. If the Commission comes to the conclusion that some remedial actions with respect to the Work are required, the Commission will instruct the Contractor to carry out such remedial actions without delay. The


April 2016

16

Final Report shall include a fully detailed description of the Work completed in accordance with Sections 4, 5 and 6 above and a description of the remedial actions taken, if any.

If the Commission, after the review of the Final Report, requires further information and/or more detailed description of remedial actions taken, the Commission will instruct the Contractor to revise the Final Report to include such additional information and/or a more detailed description of the remedial actions, and submit Revised Final Report to the Commission within 4 (four) weeks of the instruction for review and acceptance.

8.1.5 Initial Testing Monthly Reports / Additional Initial Testing Monthly Reports

During the Initial Testing period, the Contractor shall submit monthly reports for the Initial Testing activities, including copies of the logs and readings taken as a part of this work, invoices for fuel and consumables and description of any problem with the Station.

In case Optional Extension of the Initial Testing is requested by the Commission as described in Section 6 , the Contractor shall submit Additional Initial Testing Monthly Reports as described in the above paragraph of this Section of the ToR.

8.2 ACCEPTANCE OF WORK

a) Work Task 1: “SITE PREPARATION AND CONSTRUCTION OF THE STATION” under Section 4 of these ToR shall be completed not later than 6 (six) months. The completion of Work Task 1 is marked by the acceptance by the Commission of Work Task Progress Report 1/ Revised Work Task Progress Report 1 and acceptance by the Commission of Work Task Progress Report 2/ Revised Work Task Progress Report 2.

b) Work Task 2: “INSTALLATION SUPPORT” of these ToR shall be delivered throughout the entire duration of the Contract to to ensure that the other Work Tasks are meeting the required timelines as set out in these ToR. The completion of Work Task 2 is marked by the acceptance by the Commission of Final Report/Revised Final Report.

c) Work Task 3: “INITIAL TESTING” under Section 6 of these ToR shall be completed in accordance with the time schedule agreed and approved by the Commission. The Initial Testing Monthly Reports shall be submitted in accordance with Section 8.1.5 of these ToR.

9 LIST OF ATTACHMENTS

Attachment I Minimum Requirements for Infrasound Station Specifications;

Attachment II Power Supply systems of IS20 Preliminary Design;

Attachment III Communication System of IS20 Preliminary Design;

Attachment IV Guidelines for Grounding and Lightning Protection;

Attachment V GCI Outdoor Antenna and Indoor Equipment Requirements;


April 2016

17

Attachment VI Specifications for Station’s Vehicle.


April 2016

18

Figure 1. Location of station IS20, Galapagos Islands.

Figure 2. Layout of station IS20, Galapagos Islands.


April 2016

19

Figure 3. 96-port 18-m diameter wind-noise-reduction system to be installed at each array element of the Station.

Figure 4.. 96-port 18-m diameter wind-noise-reduction system inlet port.

INLET PORTS

6 m

PIPE P2.1

3 m

PIPE P2.2

MANIFOLD


April 2016

20

Figure 5. View of installed WNRS

Figure 6. A sample of pre-fabricated equipment vault installed at the concrete base. A meteorological mas is shown right of the vault.


April 2016

21

Figure 7. A sample of a fiber optic splice box.

Figure 8 A sample view of a CRF with building and GCI antenna.


April 2016

22

Figure 9. A possible layout of the CRF building.


April 2016

23

Figure 10. A possible layout of the CRF.

40

m

N


April 2016

24

Figure 11. Meteorological mast.

Piece of pipe 50x50 mm

Attachment I. ToR for the site preparation IS20 Galapagos Ecuador

1

Attachment I. Minimum Requirements for Infrasound Station Specifications (Table 5, Page 47: CTBT/PC/II/Add.2 16 May 1997)

Minimum requirements for station specifications

CHARACTERISTICS MINIMUM REQUIREMENTS

Sensor type Microbarograph

Number of sensors 4-element array(1)

Geometry Triangle with a component at the centre

Spacing Triangle basis: 1 to 3 km(2)

Station location accuracy 100 m

Relative sensor location 1 m

Measured parameter Absolute(3) or differential pressure

Passband 0.02 to 4 Hz

Sensor response Flat to pressure over the passband

Sensor noise 18 dB below minimum acoustic noise(4)

Calibration <5% in absolute amplitude(5)

State of health Status data transmitted to the International

Data Centre

Sampling rate 10 samples per second

Resolution 1 count per 1 mPa

Dynamic range 108 dB

Timing accuracy 1 msec

Standard temperature range -10 °C to +45 °C(6)

Buffer at station or at National Data Centre 7days

Data format Group of Scientific Experts format

Data frame length 30 seconds

Data transmission Continuous

Data availability 98%

Timely data availability 97%

Mission capable array 3 elements operational

Acoustic filtering Noise reduction pipes (site dependent)

Auxiliary data Meteorological data (7) ____________________________________________________________________________________________________________________________ 1 In case of noisy sites or when increased capability is required, number of components can be increased.

2 3 km is the recommended spacing

3 Used for daily state of health.

4 Minimum noise level at 1 Hz : ~ 5 mPa

5 Periodicity: once per year (minimum).

6 Temperature range to be adapted for some specific sites.

7 Once per minute (minimum).

ATTACHMENT II TO THE TECHNICAL TERMS OF REFERENCE

POWER SUPPLY SYSTEM

IS20 GALAPAGOS ISLAND

ECUADOR

PRELIMINARY DESIGN

CRF1N~50Hz 230V

POSSIBLE CABLE RUN

IS20 GALAPAGOS ISLAND, POWER SYSTEM

PAVEL MARTYSEVICH

15/09/2015

Date Title

Drawer

SHEET 1 OF 7

H6

H5

H2

H3

H1

H4

H7

H8

NOTE: THE SCHEME IS PRELIMINARY. THE CONTRACTOR SHALL PROVE

THE CABLE ROUTES AND CAN CHANGE THEM IF NECESSARY.

1N~50Hz 230V

1N

~50H

z 2

30V

1N~50Hz 230V

1N~50Hz 230V

1N

~50H

z 2

30V

300 M

600 M

350 M

350

M

600 M

450 M

850 M

1000 M

CRF

H5

H4

H7

H6 H2

H1

H8

LINE SCHEME

PAVEL MARTYSEVICH

15/09/2015

Date Title

Drawer

SHEET 2 OF 7

H3



1N~50Hz 230V 1N~50Hz 230V 1N~50Hz 230V 1N~50Hz 230V

1N

~5

0H

z 2

30

V

1N~50Hz 230V

1N

~5

0H

z 2

30V

1N

~5

0H

z 2

30V


300 M 600 M 350 M

35

0 M

60

0 M

450 M

85

0 M

1000 M

CRF

EQUIPMENT

3P

EN

~5

0H

Z 2

30/3

80V

G DIESEL-GENERATOR

AQ1 AUTOMATIC CHANGE-CONTACT SWITCH, TO BE CHOSEN BY THE CONTRACTOR

3P

EN

~5

0H

Z 2

30

/38

0V

1PEN~50HZ 220V

L2: TO H1 AND H8

8

ARRAY ELEMENTS H1 TO H8AQ1

OVERVIEW

PAVEL MARTYSEVICH

Date Title

Drawer

SHEET 3 OF 7

EQUIPMENT

VAULT

15/03/2016 IS20 GALAPAGOS ISLAND, POWER SYSTEM

3~

50

HZ

13

KV

N

3

3

3

3

PE

TR1A1

A2

3

3

F1

3P

EN

~5

0H

z 2

20/

38

0V

LIGHTING,

BUILDING

PE

PE

Q2Q2

F3 F3

AQ1

AQ3 AQ4

GENERATOR

RS1 RS1

AQ5

RS1

4

4

AQ6

4

4

AQ7

AIR CONDITIONING

PART LIST:

A1: SURGE ARRESTOR, TO BE CHOSEN BY CONTRACTOR

A2: SURGE ARRESTOR DEHN DV M TNC 2556

A3: SURGE ARRESTOR DEHN DFL M 255 (MOUNTED AT THE POWER ENTRY OF THE IMS

COMPUTER RACK)

A4: COAXIAL SURGE ARRESTOR, SUPPLIED AND INSTALLED BY THE COMMISSION

Q1, Q2: MANUAL SWITCHES, TO BE CHOSEN BY THE CONTRACTOR

AQ1: AUTOMATIC CHANGE-CONTACT SWITCH

AQ2 - AQ7: AUTOMATIC SWITCHES, TO BE CHOSEN BY THE CONTRACTOR

F1, F2, F3: FUSES, TO BE CHOSEN BY THE CONTRACTOR

RS1: RESIDUAL SWITCH, TO BE CHOSEN BY THE CONTRACTOR

TO THE ARRAY

ELEMENTS

SAT.

ANTENNA

IMS & SATELLITE

EQUIPMENT

A2

A2

A3

A4

A6

AQ2

POWER AND EARTHING LINES

COMMUNICATION LINES

EARTHING CONTOURS

1NPE~50Hz 220V

CF POWER SUPPLY & SURGE PROTECTION

PAVEL MARTYSEVICH

Date Title

Drawer

SHEET 4 OF 7

1NPE~50Hz 220V


AQ2

3~50Hz 13kV

3P

EN

~5

0H

z 2

20/

38

0V

N

3

3

3

3

PE

TR1A1

3

3

F2

3 F1

A1

PIPE ARRAY

POWER CABLE

3 M

HORIZONTAL EARTH ELECTRODE, COPPER OR

STAINLESS STEEL TAPE OR ROUND, MINIMUM

CROSS-SECTION 100 SQ. MM AND DEPTH 0.8 M.

VERTICAL EARTH ELECTRODE, COPPER-CLAD OR

STAINLESS STEEL ROUND OR PROFILED, MINIMUM

CROSS-SECTION 100 SQ. MM, AND 3 M LONG.

REMOTE ELEMENT GROUNDING

PAVEL MARTYSEVICH

Date Title

Drawer

SHEET 5 OF 7


VAULT

3 M 3 M

3 M

3 M

7 M

1N~50Hz 220V

SENSOR 2

1NPE~50Hz 220V

EQUIPMENT VAULT

METEOROLOGICAL

STATION

2 -

- 1

2 V

MBB

2

RS2

B1

B3

B1 220V POWER DISTRIBUTION BOARD (PROVIDED BY COMMISSION)

B2 POWER SUPPLY BOX (PROVIDED BY COMMISSION)

B3 METEOROLOGICAL STATION SPD BOX (PROVIDED BY COMMISSION)

F2 T3 FUSE DIAZED 10A, GG

MBB MAIN BONDING BAR

A6 DEHN DV M TT 2P 255 (PROVIDED BY COMMISSION)

A7 GPS SURGE ARRESTOR (PROVIDED BY COMMISSION)

PF POWER FILTER (PROVIDED BY COMMISSION)

RS2 AUTO-RESETTABLE RESIDUAL SWITCH (PROVIDED BY COMMISSION)

~=

PF

10 mm2

B2

A6

PE

DIGITIZER

2 -- 12 V

MODEM

GPS

ANTENNA

4

A7

COMMUNICATION LINES

EARTHING CONTOURS


H1 ELEMENT POWER DISTRIBUTION

PAVEL MARTYSEVICH

Date Title

Drawer

SHEET 6 OF 7


F2

PF

SENSOR 1

17/03/2016

COMMUNICATION LINES

EARTHING CONTOURS


H2-H8 ELEMENT POWER DISTRIBUTION

PAVEL MARTYSEVICH

Date Title

Drawer

SHEET 7 OF 7


1N~50Hz 220V

SENSOR 2

1NPE~50Hz 220V

EQUIPMENT VAULT

MBB

2

RS2

B1

B1 220V POWER DISTRIBUTION BOARD (PROVIDED BY COMMISSION)

B2 POWER SUPPLY BOX (PROVIDED BY COMMISSION)

F2 T3 FUSE DIAZED 10A, GG

MBB MAIN BONDING BAR

A6 DEHN DV M TT 2P 255 (PROVIDED BY COMMISSION)

A7 GPS SURGE ARRESTOR (PROVIDED BY COMMISSION)

PF POWER FILTER (PROVIDED BY COMMISSION)

RS2 AUTO-RESETTABLE RESIDUAL SWITCH (PROVIDED BY COMMISSION)

~=

PF

10 mm2

B2

A6

PE

DIGITIZER

2 -- 12 V

MODEM

GPS

ANTENNA

4

A7

F2

PF

SENSOR 1

IS20 GALAPAGOS

COMMUNICATION SYSTEM

PRELIMINARY DESIGN DOCUMENT

ATTACHMENT III TO THE TECHNICAL TERMS OF REFERENCE

CRF

H6

H5

H2

H3

H1

H4

H7

H8



300 M

600 M

350 M

350

M

600 M

450 M

850 M

1000 M

18 OR 3 X 6

6

24 O

R 4

X 6

42 OR 7 X 6

48 OR 8 X 6

6

12 OR 3 X 6

6

LAYOUT

PAVEL MARTYSEVICH

05/10/2015

Date Title

Drawer

SHEET 1 OF 6

IS20 GALAPAGOS, COMMUNICATION SYSTEM

CRF

LINE SCHEME

PAVEL MARTYSEVICH

05/10/2015

Date Title

Drawer

SHEET 2 OF 6

CRF

H5

H4

H7

H6 H2

H1

H8H3

800 M 600 M 350 M

35

0 M

60

0 M

450 M

85

0 M

1000 M

18 OR 3 X 6 6

6

24 OR 4 X 6

6

12 OR 2 X 6

42 OR 7 X 648 OR 8 X 6


FO

CR

OS

S-C

AB

INE

T

FO

19

" RA

CK

UN

IT

POWER SUPPLY

220VAC OR 24 VDC

FO PATCH CABLES

CS/E/FO/SC/SC

LAN ETHERNET

CABLE, RJ45-

RJ45

POWER CABLE

LAN HUB

CENTRAL

FACILITY

H1 ARRAY

ELEMENT

H7 ARRAY

ELEMENT

H6 ARRAY

ELEMENT

6

H5 ARRAY

ELEMENT

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE

FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

M

E

T

E

O

SYSTEM OVERVIEW


PAVEL MARTYSEVICH

05/10/2015

Date Title

Drawer

SHEET 3 OF 6

H2 ARRAY

ELEMENT

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO CROSS-CABINET

CS/E/FO/SC/SC

CS

/E/S

/00

1

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

4

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

4

H8 ARRAY

ELEMENT

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

H4 ARRAY

ELEMENT

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

4H3 ARRAY

ELEMENT

3

CS/E/S/0014

POWER CABLE

CS/E/P/001

SENSOR

DIGITIZER

12 VDC

DISTRIBUTION

FO INTERFACE

BOX

ETHERNET

DATA CABLE FO PATCH

CABLE

FO

CR

OS

S-C

AB

INE

T

CS/E/FO/SC/SC

6

18

24

42

12

6

48

LIST OF RECEPTACLES:

ETHERNET IN: 4 X MS3112E8-4S

POWER IN: 1 X MS3102E-16-10P

FO LINE: CABLE GLAND OR BULK-THROUGH RECEPTACLE.

ALL THE RECEPTACLES MUST HAVE DUST CAPS.

LIST OF RECOMMENDED PARTS:

ENCLOSURE: SAREL 3D, 83304;

RAIL: DIN TS35.

MEDIA CONVERTER: INDUSTRIAL, RAIL-MOUNTED, AUTO TX/RX DETECTION, 12/24

VDC POWER SUPPLY, SC/PC CONNECTORS.

CIRCUIT BREAKER: 3 A;

MS3112E8-4S

ETHERNET INMS3102E-16-10P

12 VDC POWER IN

CIRCUIT

BREAKER

CABLE GLAND FOR

FO PATCH CABLE

12 VDC

24

VD

C

GROUND

1 CABLE CS/I/S/002, SEE SHEET 5

FIBER OPTIC INTERFACE BOX

PAVEL MARTYSEVICH

05/10/2015

Date Title

Drawer

SHEET 4 OF 6

PO

RT

PO

RT

PORT 6PORT 4

PORT 3 PORT 5

PORT 2

PORT 1

1

2

3

4

5

6

1 1 1 1

MEDIA CONVERTER

RJ45 PORTSFO SC

PORTS


MEDIA CONVERTERS ( X 8)

SC/PC RECEPTACLES

RJ45 PORTS

19" RACK MOUNT TRAY

(4.45 cm H x 43.2 cm W x 22.9 cm)

THE FIBER OPTIC RACK UNIT INCLUDES:

1. 19" RACK MOUNT TRAY

2. 8 X MEDIA CONVERTERS

3. POWER SUPPLY 220/12 V

3. INTERNAL POWER & SIGNAL CABLING

RACK UNIT FRONT VIEW

PAVEL MARTYSEVICH

05/10/2011

Date Title

Drawer

SHEET 5 OF 6


CS/E/S/001-2M

EXTERNAL ETHERNET CABLE TO DIGITIZER

MS3116J8-4P

TX+

TX-

RX+

RX-

TBD

A

B

C

D

ORG

WHT/ORG

GRN

WHT/GRN

CAT5 FTP

DIGITIZERINTERFACE BOX

MS3106F16-10S

A

B

C

RED OR BRN

BLK OR BLUE

+12 V

0 V

GND

SPLIT END

INTERFACE BOX

CS/E/P/001-2

EXTERNAL POWER CABLE FOR INTERFACE BOX

RJ45MS3116J8-4P

TX+

TX-

RX+

RX-

1

2

3

6

A

B

C

D

ORG

WHT/ORG

GRN

WHT/GRN

LAPTOPINTERFACE BOX

CS/E/S/004-2M

EXTERNAL ETHERNET CONFIGURATION CABLE

CAT5 FTP

RJ45MS3116J8-4P

TX+

TX-

RX+

RX-

1

2

3

6

A

B

C

D

ORG

WHT/ORG

GRN

WHT/GRN

LAN SWITCH

CS/I/S/002

INTERNAL ETHERNET CABLE

CAT5

BOX RECEPTACLE

CABLES

PAVEL MARTYSEVICH

05/10/2015

Date Title

Drawer

SHEET 6 OF 6


Version 1.1/01-2010

CTBTO/IMS Earthing and

Lightning Protection Minimum

Standard

Attachment V. ToR for the site preparation IS40 – AS076, Keravat, PNG

martysevich

Typewritten Text

martysevich

Typewritten Text

ATTACHMENT IV TO THE TERMS OF REFERENCE

martysevich

Typewritten Text

Version 1.1/01-2010

TABLE OF CONTENT

1 Introduction ......................................................................................... 4

2 General Part ......................................................................................... 5

2.1 Lightning activity and exposure.......................................................... 5

2.1.1 Frequency of lightning strikes ................................................................. 5

2.1.2 Direct lightning strikes to a structure....................................................... 6

2.1.3 Assessment of the average annual number of dangerous events due to flashes near a structure NM .............................................. 7

2.1.4 Direct and indirect lightning strikes to an incoming overhead line or cable ................................................................................................... 8

2.2 Lightning Protection System (LPS) .................................................. 10

2.2.1 Air-termination system .......................................................................... 11

2.2.2 Down-conductors.................................................................................. 13

2.2.3 Earth-termination system ...................................................................... 14

2.2.4 Equipotential bonding ........................................................................... 23

2.2.5 Surge Protection ................................................................................... 28

3 CTBTO/IMS Specific Part ...................................................................42

3.1 Classification of CTBTO/IMS stations .............................................. 42

3.1.1 Classification in terms of lightning exposure ......................................... 42

3.1.2 Classification in terms of Lightning Protection Zones ........................... 42

3.2 Protection of the Central Recording Facility .................................... 43

3.2.1 Air Termination system and down-conductors ...................................... 43

3.2.2 Earth termination system ...................................................................... 43

3.2.3 Equipotential bonding system ............................................................... 44

3.2.4 Surge protection ................................................................................... 44

3.3 Protection of the remote elements .................................................... 45

3.3.1 Air termination system .......................................................................... 46

3.3.2 Down-conductors.................................................................................. 47

3.3.3 Earth-termination system ...................................................................... 47

3.3.4 Equipotential Bonding system .............................................................. 50

3.3.5 Surge Protection ................................................................................... 51

3.4 Technology Specific Situations ........................................................ 51

3.4.1 Seismic Monitoring Stations ................................................................. 51

3.4.2 Infrasound Monitoring Stations ............................................................. 52

3.4.3 Hydroacoustic Monitoring Stations ....................................................... 52

3.4.4 Radionuclide Monitoring Stations ......................................................... 53


CTBTO/IMS Earthing and Lightning Protection Minimum Standard

Version 1.1/01-2010 - 3 -

Annex A Maintenance and inspection of the Lightning Protection System ................................................................................................. 54

A.1 General ................................................................................................. 54

A.2 Recommended frequency of inspection ............................................... 54

A.3 Visual inspection................................................................................... 54

A.4 Testing .................................................................................................. 55

Annex B Soil resistivity measurements ........................................................... 56

B.1 Specific earth resistance ρE .................................................................. 56

B.2 Seasonal fluctuations ........................................................................... 57

B.3 Measurement of specific earth resistance ρE [8], [10] .......................... 58

Annex C Earthing Electrode System Testing/Verification .............................. 60

C.1 Overview .............................................................................................. 60

C.2 3-pole/4-pole Measurement of Earthing Resistance ............................. 60

C.3 Clamp-on Ohmmeter ............................................................................ 62

C.4 Prerequisites for Testing ....................................................................... 63

C.5 Required Test Equipment and Supplies ............................................... 65

Annex D Dissimilar Metals and Corrosion Control ......................................... 68

D.1 Choice of earth electrode materials ...................................................... 69

D.1.1 Hot-dip galvanized steel ....................................................................... 69

D.1.2 Bare steel ............................................................................................. 69

D.1.3 Steel with copper sheath ...................................................................... 69

D.1.4 Bare copper .......................................................................................... 69

D.1.5 Stainless steels .................................................................................... 69

D.2 Combination of earth electrodes made of different materials ............... 70

D.3 Methods to help reduce Corrosion ....................................................... 71

D.3.1 Galvanized steel connecting cables from foundation earth electrodes to down conductors ............................................................. 71

D.3.2 Earth entries ......................................................................................... 71

D.3.3 Underground terminals and connections .............................................. 71

Annex E Lightning Protection System Compliance Matrix ............................ 72

Annex F List of Abbreviations .......................................................................... 78

Annex G References .......................................................................................... 79



Version 1.1/01-2010 - 4 -

1 Introduction

The International Monitoring System (IMS) consists of a worldwide network of 321 stations, including primary and auxiliary seismic, hydroacoustic, infrasound and radionuclide monitoring stations supported by 16 radionuclide laboratories. The IMS facilities transmit data using a closed and secure satellite communications network via the Global Communications Infrastructure to the International Data Centre (IDC) in Vienna using very small aperture terminal technology.

The IMS network is required to be in continuous operation with high data availability requirements in the IDC, which can be summarized as 98% for seismic, hydroacoustic and infrasound stations and 95% for radionuclide monitoring stations.

Many stations are located in areas with high annual ground flash density and unreliable mains power. At those locations, the equipment is subject to damage caused by lightning, both direct strikes and surges from indirect flashes, and by electrical surges. This seriously affects the data availability requirements.

This document provides information about the lightning protection and installation of earth-termination system, lightning equipotential bonding and surge protection designated to minimize damage caused by these events.

In general, the cases which require lightning protection are the following:

(1) Existence of large crowds (2) Necessity of service continuity (3) Very high lightning flash frequency (4) Tall isolated structures (5) Buildings containing explosive or flammable materials (6) Buildings containing irreplaceable cultural heritage

For CTBTO/IMS stations cases (2), (3) and (4) are applicable and hence proper lightning protection is needed in order to achieve the expected performance.

The main and most effective measure for protection of structures against physical damage is considered to be the Lightning Protection System (LPS). It usually consists of both external and internal lightning protection systems.

The external LPS is intended to intercept direct lightning flashes to the structure, including flashes to the side of the structure, and to conduct the lightning current from the point of strike to the ground. The external LPS is also intended to disperse this current into the earth without causing thermal or mechanical damage, nor dangerous sparking which may trigger fire or explosions.

An internal LPS prevents dangerous sparking within the structure using either equipotential bonding or a separation distance (and hence electrical insulation) between the external LPS components and other electrically conducting elements internal to the structure.

IEC Standard 62305, made up of four parts [1], [2], [3] and [4] provides all basic information for a proper lightning protection of CTBTO/IMS stations.


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2 General Part

2.1 Lightning activity and exposure

The probability that a structure or object will be struck by lightning is the product of the equivalent collection area of the structure or object and the flash density for the area that the structure is located.

Lightning Flash Density (Ng), sometimes also called Ground Flash Density, is the average yearly number of flashes to ground per square kilometer. This value is available from ground flash location networks in some areas of the world. If a map of Ng is not available, in temperate regions Ng may be estimated by:

dg TxN 1.0

where Td is the average number of thunderstorm days per year (which can be obtained from isokeraunic maps from local meteorological services).

For some tropical regions correlations have been found [5], which are different from the more general one given above:

12.1024.0 dg TxN

for mountainous regions in Mexico 12.1030.0 dg TxN for mountainous regions in Brazil

56.10017.0 dg TxN for Colombia.

Another estimate of Ng may be obtained from thunderstorm hour records by:

1.1054.0 hg TxN

where Th is the average number of thunderstorm hours per year [6].

For Ng equal or higher than 4, lightning protection is strongly recommended.

2.1.1 Frequency of lightning strikes

It is necessary to distinguish between the following frequencies of lightning strikes which can be relevant for a building or structure:

Nd Frequency of direct lightning strikes to the building or structure; NM Frequency of close lightning strikes with electromagnetic effects; NL Frequency of direct lightning strikes in utility lines entering the building or

structure; NI Frequency of lightning strikes adjacent to utility lines entering the building or

structure.



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2.1.2 Direct lightning strikes to a structure

The yearly lightning strike frequency (Nd) to a structure (as a CTBTO/IMS site) is determined by the following equation [1]:

610xCxAxNN ddgd where: Nd is the yearly lightning strike frequency to the site Ng is the yearly average flash density in the region where the structure is located Ad is the collection area of the structure (m2) Cd is the Location Factor (see Table 1).

Table 1: Location Factor Cd

Relative location Cd

Structure surrounded by higher objects or trees 0,25 Structure surrounded by objects or trees of the same heights or smaller 0,5

Isolated structure: no other structures in the vicinity 1

Isolated structure on a hilltop or a knoll 2

The Collection Area (Ad) refers to the ground area having the same yearly direct lightning flash probability as the structure. It is an increased area for the structure that includes the effect of the height and location of the structure.

For isolated structures on flat ground, the collection area Ad is the area defined by the intersection between the ground surface and a straight line with 1/3 slope which passes from the upper parts of the structure (touching it there) and rotating around it (see Figure 1). Determination of the value of Ad may be performed graphically (Figure 1) or mathematically:

Ad = L x W + 6 x H x (L+W) + 9 x π x H2

with L, W and H expressed in meters. For more complex and non rectangular structures see e.g. IEC 62305-2, A.2.1.1.



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Figure 1: Calculation of the collection area Ad for a rectangular structure

In case of a typical CTBTO/IMS site with underground vaults, a surrounding fence of height HF and a radio tower of height HT the collecting area Ad can be estimated as shown in Figure 2.

Figure 2: Collection area Ad for a rectangular structure and a radio tower of height HT

2.1.3 Assessment of the average annual number of dangerous events due to flashes near a structure NM

Average annual number of dangerous events due to flashes near a structure NM may be evaluated as the product:

NM = Ng × (Am – Ad x Cd) ×10–6

where Ng is the lightning ground flash density (flash/(km2 x year)); Ad is the collection area for the structure (see Figure 1) Am is the collection area of flashes striking near the structure (m2).



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The collection area Am extends to a line located at a distance of 250 m from the perimeter of the structure (see Figure 3)

Figure 3: Collection area Am, Al, and Ai for a rectangular structure

For a rectangular structure of length L and width W the collection area Am is given by:

Am = L x W + 2 x (L+W) x 250+2502 x π

2.1.4 Direct and indirect lightning strikes to an incoming overhead line or cable

The frequency of lightning to or nearby a service line (power, data line, telecommunication, etc) entering a building or a station can be estimated by:

NL = Ng × Al × Ce × 10–6 (direct strikes)

Ni = Ng × Ai × Ce × 10–6 (indirect strikes)

Ce is the environment factor (in rural areas Ce is 1).

Al is a function of the type of line (overhead line or buried cable) and the length LC

of the line. In the case of buried cables, it is also a function of the earth resistivity ρ; and for overhead lines it depends on the height of the line (H) above ground level (see Table 2).



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Table 2: Equivalent interception areas Al and Ai for utility lines

Overhead Line Underground cable

Al CbaC HxxHHxL 63 )( xHHxL baC )(3

Ai CLx1000 xLx C25

Al is the collection area of flashes striking the service (m2); Ai is the collection area of flashes to ground near the service (m2); Hc is the height of the service conductors above ground (m); Lc is the length of the service section from the structure to the first node (m). A

maximum value Lc = 1 000 m should be assumed; Ha is the height of the structure connected at end “a” of service (m); Hb is the height of the structure connected at end “b” of service (m); ρ is the earth resistivity (Ωm) in or on which the line is laid, up to a maximum

value of ρ NOTE: The structure to be protected shall be assumed to be the one connected at “b” end of

service



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2.2 Lightning Protection System (LPS)

a) Definitions:

The lightning protection system is the complete system used to reduce physical damage due to lightning flashes to the structure and lightning caused surges on power and data lines.

The external LPS is intended to intercept direct lightning flashes to the structure and conduct the lightning current from the point of strike to ground and to disperse this current into the earth without causing thermal or mechanical damage, nor dangerous sparking which may trigger fire or explosions.

In most cases, the external LPS is attached to the structure to be protected. An isolated external LPS should be considered when the thermal and explosive effects at the point of strike, or on the conductors carrying the lightning current, may cause damage to the structure or to the contents (see paragraph 5.3.2 in 62305-3).

b) Lightning Protection Level Classification:

According to [1] (IEC 62305-1) there exist four Lighting Protection Levels (LPL): LPL I, II, III and IV. For each LPL a set of maximum and minimum lightning current parameters is fixed. Only 1% of lightning events will exceed the maximum values of lighting current parameters specified for LPL I. For LPL II the parameters are reduced to 75% of the values of LPL I. These values are 50 % of LPL I for LPL III and IV.

Lightning protection classes I, II, III and IV refer to the LPL I, II, III and IV described above.

Lightning protection measures specified in this document are based on LPL II, which provides sufficient protection for the IMS installations.

The components of a LPS are Air-Termination System, Down-conductors, Earth-termination System, Equipotential Bonding and Surge Protection based on Lightning Protection Zone (LPZ) concept.

All connections within LPS must provide permanent galvanic and mechanical connection between the components. The method of connection depends on the materials used for the LPS and can be made by brazing, welding, pressing, screwing or riveting, for example.



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2.2.1 Air-termination system

The probability of structure penetration by a lightning current is considerably decreased by the presence of a properly designed air-termination system.

Air-termination systems can be composed of any combination of the following elements (examples see Figure 4):

a) rods (including free-standing masts); b) catenary wires; c) meshed conductors.

a) b)

Figure 4: Two examples of air-termination system on buildings. a) Roof with air termination conductor and b) air-termination rod for chimney (adapted from [8])

Air-termination components installed on a structure shall be located at corners,

exposed points and edges in accordance with one or more of the following methods: – the protection angle method; – the rolling sphere method; – the mesh method. The values for the protection angle, rolling sphere radius and mesh size for each

class of LPS are given in Table 3.



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Table 3: Maximum values of rolling sphere radius and mesh size corresponding to the class of LPS

Class of LPS Rolling Sphere

Radius r (m) Mesh Size W

(m)

I 20 5 x 5

II 30 10 x 10

III 45 15 x 15

IV 60 20 x 20

Figure 5: Protection angle α corresponding to the class of LPS as a function of the height H

of air-termination above the reference plane

– The mesh method is a suitable form of protection where plane surfaces are to be

protected. – The protection angle method is suitable for simple-shaped buildings but it is

subject to limits of air-termination height H as indicated in Figure 5. – The cone-shaped protected zone provided by a vertical rod of height h and the

corresponding angle α (α being a function of h and class of LPS) is shown in Figure 6.



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– Figure 6: Protected zone of a vertical rod for a protection angle α

For class II LPS, the protection angle α and radius R of protected area at the

reference plane are given in Table 4.

Table 4: Protective angle α and distance R in Figure 6 as a function of height h for class II LPS

2.2.2 Down-conductors

Down-conductors shall be arranged in such a way that from the point of strike to the earth several parallel current paths exist. The length of those current paths must be kept to a minimum.



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An equal spacing of the down-conductors is preferred around the perimeter of a structure. Typical values of the distance between the down-conductors are given in Table 5.

Table 5: Typical values of the distance between down-conductors and between ring conductors according to the class of LPS

Class of LPS Typical Distance (m)

I 10

II 10

III 15

IV 20

A down-conductor should be installed at each exposed corner of the structure, where this is possible.

Figure 7: Example of down-conductor mounted on a brick wall

2.2.3 Earth-termination system

The main task of the earth termination system is to:

efficiently dissipate the lightning surge energy that may arrive via down- conductors of the lightning protection system;

efficiently dissipate electrical surges and faults in order to minimize the chances of human injury from either “step potentials” or “touch potentials”;

provide a stable reference for electrical and RF circuits at the facility in order to minimize noise during normal operation;



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be properly bonded to provide an equipotential plane under fault or lightning strike conditions;

be electrically and mechanically robust in order to assure performance over the “life” of the facility (nominally several 10’s of years from construction date).

The shape and dimensions of the earth-termination system are the important criteria when dealing with the dispersion of the high frequency lightning current into the ground. In general, a low earthing resistance is recommended [3], with values lower than 10 Ω when measured at low frequency.

From the viewpoint of lightning protection, a single integrated earth-termination system is preferable and is suitable for all purposes (i.e. lightning protection, power systems and telecommunication systems). Underground metallic piping and any other existing earthing system shall be bonded together to form a single integrated earth-termination system.

The earth-termination system shall have low electrical impedance, with conductors large enough to withstand high fault and lightning currents. In addition, in case of highly corrosive environment, the size of the electrodes should be large enough in order to provide sufficient life time (minimum 20 years for IMS applications). The lower the earth electrode impedance, the more effectively the earth electrode system can dissipate high energy impulses into the earth.

2.2.3.1 Earthing electrodes

The earthing electrodes are the conducting elements used to connect electrical systems and/or equipment to the earth. The earthing electrodes are placed into the soil to maintain electrical equipment at the potential of the earth and to dissipate currents into the soil. Earthing electrodes may be earthing rods, metal plates, in concrete encased conductors, earthing ring conductors, electrolytic earthing rods or the metal frame of buildings and includes also foundation earth electrodes. Typical earthing electrodes are shown in Figure 8.



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Figure 8: Typical earth electrodes and their installation

The requirements for earthing electrodes are:

The material and dimensions used for earth electrodes should conform to the materials listed in Table 6.

The behavior of the metal with respect to corrosion in the soil and in connection with dissimilar metals should always be taken into account (see Annex D ).

The vertical earth electrodes shall have a minimum length of 3 m. The actual diameter, length, and number of rods required may vary with site dimensions and/or as determined by an engineering study based on the soil resistivity profile of the site.

Where multiple connected earth electrodes are used, the separation between any two electrodes shall be at least the sum of their driven depths (where practicable).

The method of bonding earthing conductors to earth electrodes shall be compatible with the types of metals being bonded (see Table 17 in Annex D).

Earth electrodes shall be free of paint or other nonconductive coatings.

Where applicable, the earth electrodes shall be buried below the permanent moisture level.

Earth electrodes shall be buried to a minimum depth of 0.8 m below finished grade, where possible, or buried below the freeze line, whichever depth is larger.

Earth electrodes that cannot be driven straight down, due to contact with rock formations, may be driven at an oblique angle of not greater than 45 degrees



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from the vertical, or may be buried horizontally in a trench at least 0.8 m deep perpendicular to the building.

Table 6: Material, configuration and minimum dimensions of earth electrodes [3]

Note: In some areas bare steel is also allowed to be used in the soil, not

embedded in concrete. In [7] for bare steel electrodes in soil (electrodes were 2.4 m long and had a diameter of 16 mm) a 7.6 % corrosion weight loss was determined after 7 years. As the actual corrosion of bare steel is determined by local soil conditions, regular measurements of the earthing resistance of such electrodes shall be done to ensure proper earthing conditions and initiate improvements, when necessary. Corrosion is phenomena that can occur at the boundaries between two distinct soil layers. Therefore, earthing electrodes of sufficient corrosion resistivity (e.g. stainless steel, copper) shall be used.



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2.2.3.2 Earthing conductor

Earthing conductor is a conductor connecting the system component to be earthed to an earth electrode and which is installed above the ground or insulated in the ground.

2.2.3.3 Minimum site earthing requirements

As the earthing system is used for several functions in a structure (e.g. signal reference ground and lightning protection), the request for a minimum earthing resistance may have different reasons.

For lightning and overvoltage protection the absolute value of the earthing system resistance is not as important as to ensure that all equipment and conducting services are connected to a more or less equal potential plane (equipotential bonding is a must). The need to ensure an equipotential plane becomes obvious by the following simple calculation: When a typical lightning current of 10 kA is injected in an earthing system of 10 Ω, at the striking point a potential raise relative to the reference earth of 100 kV (U = I*R = 10.000 A x 10 Ω = 100.000 V) will occur and can cause flashover when bonding is not done properly.

A mesh of earth conductors with a mesh-size of about 5 m x 5 m, where towers, objects and equipment vaults are integrated, is suitable to limit potential differences among the installations and at the surface (risk of step-voltage) to acceptable values.

Since IEC 62305-3 [3] assumes a systematic lightning equipotential bonding, no particular value is required for the earth electrode resistance. In this IEC standard the minimum length I1 of the earthing electrode is a function of the class of lightning protection system (see Figure 9). For LPL II, being applicable to CTBTO/IMS stations, Table 7 shows l1 as a function of the soil resistivity in Ωm.

Figure 9: IEC 62305-3 specified minimum length l1 of each horizontal earth electrode according to the class of the LPS



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Table 7: Minimum length l1of each horizontal earth electrode as a function of ground resistivity in Ωm according to LPL II

Ω.m l1 Ω.m l1 Ω.m l1 Ω.m l1 Ω.m l1 Ω.m l10 5,0 500 5,0 1000 9,1 1500 19,3 2000 29,5 2500 39,8

10 5,0 510 5,0 1010 9,3 1510 19,5 2010 29,8 2510 40,020 5,0 520 5,0 1020 9,5 1520 19,7 2020 30,0 2520 40,230 5,0 530 5,0 1030 9,7 1530 19,9 2030 30,2 2530 40,440 5,0 540 5,0 1040 9,9 1540 20,1 2040 30,4 2540 40,650 5,0 550 5,0 1050 10,1 1550 20,3 2050 30,6 2550 40,860 5,0 560 5,0 1060 10,3 1560 20,5 2060 30,8 2560 41,070 5,0 570 5,0 1070 10,5 1570 20,8 2070 31,0 2570 41,280 5,0 580 5,0 1080 10,7 1580 21,0 2080 31,2 2580 41,490 5,0 590 5,0 1090 10,9 1590 21,2 2090 31,4 2590 41,6100 5,0 600 5,0 1100 11,1 1600 21,4 2100 31,6 2600 41,8110 5,0 610 5,0 1110 11,3 1610 21,6 2110 31,8 2610 42,0120 5,0 620 5,0 1120 11,5 1620 21,8 2120 32,0 2620 42,2130 5,0 630 5,0 1130 11,8 1630 22,0 2130 32,2 2630 42,4140 5,0 640 5,0 1140 12,0 1640 22,2 2140 32,4 2640 42,6150 5,0 650 5,0 1150 12,2 1650 22,4 2150 32,6 2650 42,8160 5,0 660 5,0 1160 12,4 1660 22,6 2160 32,8 2660 43,0170 5,0 670 5,0 1170 12,6 1670 22,8 2170 33,0 2670 43,3180 5,0 680 5,0 1180 12,8 1680 23,0 2180 33,2 2680 43,5190 5,0 690 5,0 1190 13,0 1690 23,2 2190 33,4 2690 43,7200 5,0 700 5,0 1200 13,2 1700 23,4 2200 33,6 2700 43,9210 5,0 710 5,0 1210 13,4 1710 23,6 2210 33,8 2710 44,1220 5,0 720 5,0 1220 13,6 1720 23,8 2220 34,0 2720 44,3230 5,0 730 5,0 1230 13,8 1730 24,0 2230 34,3 2730 44,5240 5,0 740 5,0 1240 14,0 1740 24,2 2240 34,5 2740 44,7250 5,0 750 5,0 1250 14,2 1750 24,4 2250 34,7 2750 44,9260 5,0 760 5,0 1260 14,4 1760 24,6 2260 34,9 2760 45,1270 5,0 770 5,0 1270 14,6 1770 24,8 2270 35,1 2770 45,3280 5,0 780 5,0 1280 14,8 1780 25,0 2280 35,3 2780 45,5290 5,0 790 5,0 1290 15,0 1790 25,3 2290 35,5 2790 45,7300 5,0 800 5,0 1300 15,2 1800 25,5 2300 35,7 2800 45,9310 5,0 810 5,2 1310 15,4 1810 25,7 2310 35,9 2810 46,1320 5,0 820 5,4 1320 15,6 1820 25,9 2320 36,1 2820 46,3330 5,0 830 5,6 1330 15,8 1830 26,1 2330 36,3 2830 46,5340 5,0 840 5,8 1340 16,0 1840 26,3 2340 36,5 2840 46,7350 5,0 850 6,0 1350 16,3 1850 26,5 2350 36,7 2850 46,9360 5,0 860 6,2 1360 16,5 1860 26,7 2360 36,9 2860 47,1370 5,0 870 6,4 1370 16,7 1870 26,9 2370 37,1 2870 47,3380 5,0 880 6,6 1380 16,9 1880 27,1 2380 37,3 2880 47,5390 5,0 890 6,8 1390 17,1 1890 27,3 2390 37,5 2890 47,8400 5,0 900 7,0 1400 17,3 1900 27,5 2400 37,7 2900 48,0410 5,0 910 7,3 1410 17,5 1910 27,7 2410 37,9 2910 48,2420 5,0 920 7,5 1420 17,7 1920 27,9 2420 38,1 2920 48,4430 5,0 930 7,7 1430 17,9 1930 28,1 2430 38,3 2930 48,6440 5,0 940 7,9 1440 18,1 1940 28,3 2440 38,5 2940 48,8450 5,0 950 8,1 1450 18,3 1950 28,5 2450 38,8 2950 49,0460 5,0 960 8,3 1460 18,5 1960 28,7 2460 39,0 2960 49,2470 5,0 970 8,5 1470 18,7 1970 28,9 2470 39,2 2970 49,4480 5,0 980 8,7 1480 18,9 1980 29,1 2480 39,4 2980 49,6490 5,0 990 8,9 1490 19,1 1990 29,3 2490 39,6 2990 49,8500 5,0 1000 9,1 1500 19,3 2000 29,5 2500 39,8 3000 50,0



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The minimum length of each earth electrode is:

I1 for horizontal earth electrodes I1 x 0.5 for vertical or inclined earth electrodes (with a minimum of 3 m)

The determined values of l1 apply to each individual earth electrode. For meshed earth electrodes and foundation earth electrodes the average radius r of the area enclosed by the earth electrode must be not less than the given minimum length l1 in Figure 9 according to the selected class of LPS. To determine the average radius r, the area under consideration is transferred into an equivalent circular area and the radius is determined as shown in Figure 10.

Figure 10: Equivalent radius of a residential building in order to compare with minimum length l1 of each horizontal earth electrode according to the class of LPS [8]

In the example shown in Figure 10 the calculated equivalent radius of 5.89 m for the given ring electrode around the buildings area A1 is larger than the minimum length of 5 m (see Figure 9 for LPS class III) and hence no further earth electrodes are required.

2.2.3.4 Calculation of earth electrode resistances

Table 8 gives some formulas for estimating the earth electrode resistance of the most common types of earth electrodes. In practice, these approximate formulas are quite sufficient, when keeping in mind all the variable parameters of the ground sub-surface (soil humidity, temperature, homogeneity of soil, etc.)



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Table 8: Formulae for calculating the earth electrode resistance RA for different earth electrodes

2.2.3.5 Special earthing situations

The earthing resistance of the total earthing systems should be as low as possible, nevertheless it is always most important to ensure minimum potential differences within the protected area including towers, buildings and equipment vault. Independent of the actual earthing conditions (e.g. on a mountain top, in arctic region or coral environment) a safe operation of equipment is achievable when all equipment is on more or less the same potential and all lines entering the equipotential area are well bonded and protected by SPDs. Some examples are given below.

Towers with limited space for an earthing ring

Towers installed close to buildings may not have adequate space for a complete tower earthing ring or for earthing rods spaced properly to achieve the resistance requirements of the site. The tower earthing shall be integrated with the earthing system of the adjacent buildings and an earthing mesh (with optional earthing rods) shall be installed across the available space (example see in Figure 11).



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Figure 11: Linear earthing electrode system in case of limited space (typically one rod every 5 m or twice the length of the rod)

Earth electrodes in rocky soil, sand, coral, limestone, arctic ice or mountain tops

Some sites are located on mountaintops or in areas with rocky soil. In the instances where there is no soil or very little soil at the site (shallow topsoil environment, arctic regions, sand, coral, or limestone environments, etc.) special designs will be needed. Surface earth electrodes such as ring earth electrodes or star-type earth electrodes are often the only way to create an earth-termination system. When installing the earth electrodes, the flat strip or round material is laid on the stony ground, the ice or on the rock. Even where a foundation earth electrode has a reduced earthing effect in rocky soil, it still acts as an equipotential bonding conductor. If the earth electrode cannot be installed in the soil and has to be mounted on the surface, it should be protected against mechanical damage. Radial earth electrodes lying on or near the earth surface should be covered by stones or embedded in concrete for mechanical protection. The clamped points should be installed with particular care and be protected against corrosion (anticorrosive band).

In conditions described above, the main target to be achieved is an earth termination system providing sufficient equipotential plane. The achievement of a low grounding resistance is a secondary task.

An example for the extension of the earthing system of a tower to nearby areas with low soil resistivity is shown in Figure 12.



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Figure 12: Example of site on mountain top with earthing wires from the tower to nearby areas with low soil resistivity

2.2.4 Equipotential bonding

Lightning strikes can give rise to harmful potential differences in and on a building/structure. The major concern in the protection of a building/structure is the occurrence of potential differences between the conductors of the lightning protection system and other grounded metal bodies and wires belonging to the building. These potential differences are caused by resistive and inductive effects and can result in dangerous sparking or damage of electronic equipment.

2.2.4.1 Bonding to the earth termination system

Equipotential bonding is required to remove or to reduce potential differences between various installations. Bonding prevents e.g. hazardous touch voltages between the protective conductor of the low voltage electrical power consumer’s installations and metal, water, gas and heating pipes.

The equipotential bonding consists of a main equipotential bonding bar (MBB) where the following extraneous conductive parts shall be directly connected (see Figure 13):

main equipotential bonding conductor foundation earth electrodes or lightning protection earth electrodes conductive parts of the building structure (e.g. lift rails, steel skeleton,

ventilation and air conditioning ducting) metal drain pipes internal gas pipes earthing conductor for antennas



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earthing conductor for telecommunication systems protective conductors of the electrical installation (PEN conductor for TN

systems and PE conductors for TT systems or IT systems) metal shields of electrical and electronic conductors metal cable sheaths of high-voltage current cables up to 1000 V

Figure 13: Principle of lightning equipotential bonding consisting of lightning and main equipotential [8]

Different types of equipotential bonding bars and their installation are shown in Figure 14.

In case, when a direct connection to the bonding bar is not possible, the installation components have to be integrated indirectly into the main equipotential bonding via isolating spark gaps (e.g. measuring earth in laboratories, if they have to be separate from the protective conductors). During normal operation the spark gap will keep the circuits insulated and whenever lightning strikes the spark gap will provide short time interconnection.

Lightning equipotential bonding connections shall be made as direct and straight as possible. For external conductive parts, lightning equipotential bonding shall be established as near as possible to the point of entry into the structure to be protected.



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Figure 14: Examples of practical design an installation of equipotential bonding bars

The minimum cross-section values of the bonding conductors connecting different bonding bars and of the conductors connecting the bars to the earth-termination system are listed in Table 9.

Table 9: Minimum dimensions of conductors connecting different bonding bars or connecting bonding bars to the earth-termination system [3]

The minimum cross-section values of the bonding conductors connecting internal metal installations to the bonding bars are listed in Table 10.

Table 10: Minimum dimensions of conductors connecting internal metal installations to the bonding bar [3]

According to [9] the minimum cross-section for earth conductors of antennas is 16 mm2 Cu, 25 mm2 Al or 50 mm2 steel.



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In order to minimize the induction loops within buildings the following is recommended:

Cables and metal pipes shall enter the building at the same point; Power lines and data lines shall be laid spatially close and have to be

shielded;

Avoid unnecessarily long cables by laying lines directly; Integration of the cable shields into the equipotential bonding by bonding the

shield at both ends. In case when a permanent bonding of the cable shield at both ends is not possible, the shield may be bonded with a spark gap.

2.2.4.2 Sub System Equipotential Bonding Bar (EBB)

Sometimes supplementary local equipotential bonding is useful. The reason behind is to interconnect all simultaneously accessible parts as well as the stationary operating equipment and also extraneous conductive parts. The aim is to keep any voltage differences between systems as low as possible.

The difference to the main equipotential bonding is the fact that the cross sections of the conductors can be chosen to be smaller, and also this supplementary equipotential bonding can be limited to a particular location. For minimum cross-section of conductors connecting internal metal installations to the bonding bar see Table 10. All connections to the bonding bar shall be as short as possible and without loops.

2.2.4.3 Internal perimeter earthing bus conductors

Enclosures and racks of electronic devices and systems should be integrated into the equipotential bonding network with short connections. This requires sufficient numbers of equipotential bonding bars and/or ring equipotential bonding bars in the building or structure. The busbars, in turn, must be connected to the equipotential bonding network (Figure 15, Figure 16).

Figure 15: Example of earthing bus



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Figure 16: Connection of the ring equipotential bonding bar with the equipotential bonding network via fixed earthing point

2.2.4.4 Equipment Earthing

Protective conductors (PE) and cable shields of the data links of electronic devices and systems must be integrated into the equipotential bonding network in accordance with the instructions of the system manufacturer. The connections can be made either in the shape of a star or as a mesh (see Figure 17 and Figure 18).

Figure 17: Star shape integration of electronic systems into the equipotential

bonding network (ERP is the earthing reference point)

Figure 18: Mesh shape integration of electronic systems into the equipotential

bonding network

When using a star point arrangement (Figure 17), all metal components of the electronic system must be suitably insulated against the equipotential bonding network. A star-shaped arrangement is therefore usually limited to applications in small, locally confined systems, such as IMS stations. In such cases, all lines must enter the building or structure, or a room within the building or structure, at a single point. The star point arrangement must be connected to the equipotential bonding network at one single earthing reference point (ERP) only.



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2.2.4.5 Equipotential bonding of AC power service connection and data lines

Equipotential bonding of AC power service connection and data lines, as part of the internal lightning protection, represents an extension of the main equipotential bonding. In addition to all conductive systems, this also integrates the supply conductors (“hot wires”) of the low voltage consumer’s installation and data lines into the equipotential bonding. The special feature of this equipotential bonding is the fact that a tie-up to the equipotential bonding is only possible via suitable surge protective devices (SPDs). Analogous to the equipotential bonding with metallic installations (see section 2.2.4.1), the equipotential bonding for AC power and data line shall also be carried out immediately at the point of entry into the structure.

If the step down transformer from medium to low voltage is located in the vicinity of IMS installation the earthing of medium voltage and low voltage system shall be interconnected, except it is in contradiction with local regulations.

2.2.5 Surge Protection

The protection of electrical and electronic systems in a structure against surges resulting from the lightning electromagnetic pulse (LEMP) is based on the principle of Lightning Protection Zones (LPZ) [4]. According to this principle, the building or structure to be protected must be divided into a number of internal lightning protection zones according to the level of threat posed by LEMP (Figure 19). This allows categorizing areas of different LEMP risk levels and to adjust protection measures to the immunity of the electronic system.

2.2.5.1 Lightning Protection Zones

Depending on the type of threat caused by the lightning, the following lightning protection zones are defined (see also Figure 19):

External

LPZ 0A: Zone is at risk from direct lightning strikes, from impulse currents up to the whole lightning current and from the whole electromagnetic field of the flash of lightning.

LPZ 0B: Zone is protected against direct lightning strikes, but at risk from the whole electromagnetic field of the flash of lightning. Internal systems can be exposed to (partial) lightning currents.

Internal

LPZ 1: Impulse currents limited by the splitting of the current and by surge protective devices (SPDs) at the zones boundaries. The electromagnetic field of the lightning flash can be attenuated by spatial shielding.

LPZ 2, 3, …. Impulse currents further limited by the splitting of the current and by surge protective devices (SPDs) at the zone boundaries. The electromagnetic field of the lightning flash is usually attenuated by spatial shielding.



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Figure 19: Lightning protection zones concept according to IEC 62305-4 [4] (figure adapted from [8])

Generally, the lightning current arrester from LPZ 0 to LPZ 1 acts like a kind of wave breaker and it conducts a large part of the interference energy away and thus protects the installation in the building from damage. Additional surge protective devices are installed at the LPZ boundary from LPZ 1 to LPZ 2 to ensure a sufficiently low level of residual interference adjusted to the immunity of the terminal device.

2.2.5.2 Types of overvoltages

Overvoltages (surges) in low-voltage systems are caused by several types of events or mechanisms [11]:

(1) Lightning overvoltages

Lightning overvoltages are the result of a direct flash to or near the power system, structures (with or without lightning protection system) or to the soil. Distant lightning flashes can also induce overvoltages in the circuits of an installation.

Lightning is a natural and unavoidable event which affects low-voltage systems (power systems as well as signal/communication systems) through several mechanisms. The obvious interaction is a flash to the power system, but other coupling mechanisms can also produce overvoltages (see Figure 20)



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S1: flashes to the structure

S2: flashes near the structure

S3: flashes to the services connected to the structure

S4: flashes near the services connected to the structure

Figure 20: Different lightning flash coupling mechanisms to a structure

For a given flash, the severity of the overvoltage appearing at the end-users facility reflects the characteristics of the coupling path such as distance and nature of the system between the point of flash and the end-users facility, earthing practices and earth connection impedance, presence of surge-protective devices (SPDs) along the path, and branching out of the distribution system. All these factors vary over a wide range according to the general practice of the utility as well as local configurations.

(2) Switching overvoltages

Switching overvoltages are the result of intentional actions on the power system, such as load, inductor or capacitor switching in the transmission or distribution systems by the utility, or in the low-voltage system by end-user operations. They can also be the result of unintentional events such as power system faults and their elimination.

(3) Temporary overvoltages (TOV)

Temporary overvoltages occur in power systems, as the result of a wide range of system conditions, both normal operation and abnormal conditions. Their occurrence is relevant to the selection of suitable surge-protective devices.

TOV are power frequency overvoltages of relatively long duration (several seconds) and may be caused by faults within the medium and low-voltage networks. The Temporary overvoltage specification of the SPD (UT) shall be greater than temporary overvoltage of the network. Otherwise the SPD will be destroyed due to an overload when TOVs occur.

2.2.5.3 Expected surge currents due to lightning flashes

For direct lightning flashes to connected services, partitioning of the lightning current in both directions of the service and the breakdown of insulation must be taken into account. As an example a 2 wire 0.5 mm2 cross section data cable will be unable to carry a 100 kA lightning current into a building. Insulation breakdown (cable damage) will occur along the line.

Considering these limitations expected surge currents for power and telecommunication/data lines are shown in Table 11.



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Table 11: Expected surge currents due to lightning flashes

2.2.5.4 Impulse withstand categories of installed equipment

So called “overvoltage categories’ or “impulse withstand categories” I, II, III, and IV are specified in the standards for testing of equipment taking into account the characteristics of the system to which it is intended to be connected [16].

Equipment of overvoltage category IV is for use at the origin of the installation (e.g. electricity meters and primary over-current protection equipment).

Equipment of overvoltage category III is equipment in fixed installations and for cases where the reliability and the availability of the equipment is subject to special requirements (e.g. switches, distribution boards, electric wall mounted sockets in the fixed installation and equipment for industrial use with permanent connection to the fixed installation).

Equipment of overvoltage category II is energy-consuming equipment to be supplied from the fixed installation (e.g. appliances, portable tools and other household and similar loads. If such equipment is subjected to special requirements with regard to reliability and availability, overvoltage category III applies).

Equipment of overvoltage category I is equipment for connection to circuits in which measures are taken to limit transient overvoltages to an appropriately low level (e.g. PCs).Table 12 shows the rated impulse voltages for equipment energized directly from the low-voltage mains. Thus installation of appropriate (and coordinated) SPDs shall limit the overvoltages to the values shown in Table 12. As an example, in a typical 230/400 V 3-phase network limitation of overvoltages to 1500 V is required for Category I equipment such as PCs or other sensitive electronic devices.



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Table 12: Rated impulse voltage for equipment energized directly from the low-voltage mains [16]

Nominal voltage of the supply system

Voltage line to neutral derived from nominal

voltages a.c. or d.c. up to and including

(V)

Rated impulse voltage in (V)

Overvoltage category

Three phase (V)

Single phase

(V) I II III IV

50 330 500 800 1500 100 500 800 1500 2500

120-240 150 800 1 500 2 500 4 000 230/400 277/480 300 1 500 2 500 4 000 6 000

400/690 600 2 500 4 000 6 000 8 000 1 000 1 000 4 000 6 000 8 000 12 000

2.2.5.5 Surge Protection Devices

A Surge Protective Device (SPD) is a device that is intended to limit transient overvoltages and divert surge currents and it contains at least one non-linear component.

2.2.5.6 SPD selection

The primary function of SPDs is to protect downstream terminal devices. They also reduce the risk of cables from being damaged. The choice of SPDs depends, among other things, on the following considerations:

Lightning protection zones of the installation site (see 2.2.5.1) Energies to be discharged Arrangement of the protective devices Immunity of the terminal devices Protection against differential-mode and/or common-mode interferences System requirements, e.g. transmission parameters Compliance with product or user-specific standards, where required Adaption to the environmental conditions / installation conditions.

2.2.5.7 SPD Technologies

SPDs are installed external to the equipment to be protected and to limit overvoltages to values below the test voltages of equipment in Table 12. Under normal conditions, the SPD has no significant influence on the operational characteristics of the systems to which it is applied. Under abnormal conditions (occurrence of a surge), the SPD responds to surges by lowering its impedance and thus diverting surge current through it to limit the voltage to its protective level. Upon return to normal conditions, the SPD recovers to a high impedance value after the surge and a possible power follow current.



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A SPD can fail or be destroyed when surges are larger than its designed maximum energy and discharge current capability. Failure modes of SPD are divided roughly in open-circuit mode and short-circuit mode.

For an open-circuit mode the system to be protected is no longer protected. In this case, a failure of the SPD is usually difficult to detect because it has almost no effect on the system. To ensure replacement of the failed SPD before the next surge, an indicating device of the SPD failure may be required.

For a short-circuit mode the system is severely affected by the failed SPD. Short-circuit current flows through the failed SPD from the power source. Thermal energy can be produced there and can result in a fire hazard before burning out and open circuit. In case the system to be protected has no suitable device to disconnect the failed SPD from its circuit, a suitable, additional disconnecting device may be required for an SPD with short-circuit failure mode.

The main components of SPDs belong to two categories [13]:

(1) Voltage-limiting type, as varistors, avalanche or suppressor diodes, etc. These SPDs are sometimes called "clamping type". Figure 21 shows the response of a typical voltage-limiting SPD to an impulse applied via a combination wave generator.

Figure 21: Typical response of a voltage-limiting type SPD such as a varistor

(2) Voltage-switching type as air-gaps, gas discharge tubes, thyristors, etc. Figure 22 shows the response of a typical voltage-switching SPD to an impulse applied via a combination wave generator.

Figure 22: Typical response of a voltage-switching type SPD such as a spark-gap



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In practice often combination type SPDs, which incorporate both voltage-switching type components and voltage-limiting type components, are used.

2.2.5.8 AC power SPD classification (Type 1, 2 and 3)

SPDs employed as part of the fixed installation are classified according to the requirements and loads on the installation sites as surge protective devices Type 1, 2 and 3 and tested according to [12].

The highest requirements (class I test in [12]) with respect to the discharge capacity are made on SPDs Type 1.The class I test is intended to simulate partial conducted lightning current impulses. SPDs Type 1 are generally recommended for locations at points of high exposure, for example, line entrances to buildings protected by lightning protection systems. These protective devices must be capable of carrying partial lightning currents, waveform 10/350 μs, many times without consequential damage to the equipment. SPDs Type 1 are called lightning current arresters and the function of these protective devices is to prevent destructive partial lightning currents from penetrating the electrical installation of a structure.

SPDs tested to class II or III test methods are subjected to impulses of shorter duration. Type 2 SPDs are generally recommended for locations with lesser exposure to direct impulses. SPDs Type 2 are called surge arresters and employed to protect against surges. Their discharge capacity is around some 10 kA (8/20 μs).

SPDs Type 3: The main function of a SPD Type 3 is to protect against surges arising between L and N in the electrical system – They may be installed in supply networks where SDPs Type 1 and/or 2 already exist. They can be installed in fixed or mobile sockets.

Type 1 SPD Type 2 SPD Type 3 SPD

Figure 23: Examples of Type 1, Type 2, and Type 3 Surge Protection Devices

2.2.5.9 SPDs for information technology systems, RF receivers and GPS

In contrary to surge protective devices for AC power supply systems, where uniform conditions can be expected with respect to voltage and frequency in 230/400 V systems, the types of signals to be transmitted in information technology (IT), control and data networks differ with respect to their

Voltage (e.g. 0 – 10 V) Current (e.g. 0 – 20 mA, 4 – 20 mA)



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Signal reference (balanced, unbalanced) Frequency (DC, NF, HF) Type of signal (analogue, digital).

Therefore, the signal must not be influenced intolerably by the use of lightning current and surge arresters in measuring and control installations. Manufacturers of SPDs offer a wide variety of surge protection elements with appropriate specifications for many applications (Ethernet, Telephone, RS232, RS442, ISDN, etc.).

When selecting SPDs, the following aspects must be especially taken into consideration:

– Protective effect (discharge capacity and protection level) – System parameters (system voltage, nominal current and transmission

parameters) – Installation environment (design, conditions of connection and certifications) Guidelines for the selection and testing of surge protective devices connected to

telecommunications and signaling networks are given in [14], [15] and by the manufacturers specifications. IEC 61643-21 [14] specifies test procedures and parameters for IT system SPDs and they must be tested with at least one of the pulses listed in Table 13.

The maximum protection level of a given SPD arisen during these tests is indicated as voltage protection level Up measured at the output of the device.

Category C tests represent especially disturbing pulses with a steep rate of rise and less energy (surge arrestors), opposite to the disturbing pulses of category D, which is supposed to simulate high energy loads due to induced partial lightning currents (lightning current arrestors). The category is also indicated in the technical data sheet of the SPDs – both in the description of the discharge capacity (In, Iimp) and protection level (Up).

Table 13: Voltage and current impulses for determining the voltage limiting characteristics of SPDs for IT systems adopted from [14]

Category Type of test

Impulse voltage

Impulse Current

Minimum number of impulses

Test for

C1

steep rate of

rise

0.5 kV or 1 kV, 1.2/50 s

0.25 kA or 0.5 kA, 8/20 s 300

surg

e ar

rest

er

C2 2 kV, 4 kV or 10 kV, 1.2/50 s

1 kA, 2 kA or 5 kA, 8/20 s

10

C3 1 kV,

1 kV/ s 10 A, 25 A or 100 A, 10/100 s

300

D1 high energy

1 kV

0,5 kA, 1 kA or 2,5 kA, 10/350 s

2 *)

*) Lightning current arrester / Combined lightning current and surge arrester



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Immunity of IT terminal devices to be protected

Within the scope of the tests for electromagnetic compatibility (EMC), electrical and electronic equipment (devices) must have a predefined immunity against conducted pulse interferences (surges). Requirements on the immunity and test constructions are specified in EN 61000-4-5 [19].

Different electromagnetic environmental conditions make different demands on the immunity of the devices. In EN 61000-4-5 test levels are subdivided into four different stages. Test level 1 includes the minimum requirements on the immunity of the terminal device. Generally, the test level can be taken from the documentation about the device or requested from its manufacturer.

Table 14: Test levels of devices according to EN 61000-4-5 [19]

Test levels according to EN 61000-4-5

Corresponds to charging voltage of the test generator

1 0.5 kV 2 1 kV 3 2 kV 4 4 kV

SPDs for use in IT systems need to limit conducted interferences to safe values to ensure that the immunity of the terminal device is not exceeded.

Depending on the building structure and the protection requirements stipulated by the Lightning Protection Zones Concept (see 2.2.5.1) it may be necessary to install lightning current and surge arresters locally separated from each other or at one point of the installation.

Examples of different types of SPDs applicable for AC power, coaxial cables (e.g. GPS signals), Ethernet and low voltage signal lines (e.g. meteorological sensors) are shown in Figure 24.

Coaxial cable (e.g. GPS) Ethernet IT system

Figure 24: Typical SPDs for coaxial cables, Ethernet and IT data lines



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Protection of GPS receiver

The GPS receiver antenna shall be placed within the area protected by a lightning rod or a structure (LPZ 0B) to avoid any direct lightning strike to the antenna.

Appropriate SPD for coaxial lines shall be placed at the entry of the antenna cable into the equipment vault or the building. Alternatively the SPD can be placed directly at the GPS clock interface. Connection to the common ground of the GPS clock and the SPD should be as short as possible.

Note: Check with the GPS clock manufacturer compatibility of the SPD with the GPS clock specifications to avoid unacceptable signal distortion.

Figure 25: Example of a SPD for coaxial cable with N-connectors

2.2.5.10 SPD for PV installations

Photovoltaic systems inevitably represent a connection to the electrical installation of a building. Today no final standard exists, specifying SPDs used to protect PV arrays, nevertheless SPD manufacturers offer appropriate SPDs. In a recent draft IEC document (IEC/82/514CD, 2008) the following specifications for surge arresters to protect PV arrays from over-voltages caused by indirect lightning strikes are requested:

a) maximum continuous operating voltage UC > 1,2 × VOC STC, where VOC STC is the open circuit voltage of a PV module at Standard Test Conditions

b) maximum discharge current Imax ≥ 5 kA c) voltage protection level UC < Up < 1,1 kV

Some SPD manufacturers offer SPDs especially designed for the application in PV installations (e.g. DEHNguard, DG PV 500 SCP).

2.2.5.11 SPD Installation Requirements

It is highly recommended that the power and signaling networks enter the structure to be protected close to each other and are bonded together at a common bonding bar. This is especially important for structures made of non-shielding material (wood, bricks, concrete, etc.).



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Connecting conductors for SPDs and any external connectors connected in series with the SPD shall be as short as possible. The residual voltage transferred to equipment will be the sum of the residual of the SPD and the inductive voltage drop along the connecting leads as shown in Figure 26. When the surge protective device in the conductor branch responds, the discharge current flows through further elements (lead conductors, fuses) causing additional dynamic voltage drops Udyn1 and Udyn2, respectively, across these impedances (Figure 26) and the protected equipment is exposed to the voltage Utotal, given by

Utotal = Udyn1 + USPD + Udyn2

Figure 26: Connection of surge protective devices in cable branches [8]

For a high frequency event as a lightning flash, the resistive component is negligible compared to the inductive component and Udyn is determined by:

dt

dixLU

imp

dyn

where L is the inductance of the lead conductor. As a general rule, the lead inductance is assumed to be 1 μH/m. This inductive voltage drop, when caused by an impulse with a rate of rise of 1 kA/μs will be approximately 1 kV/m of lead length. Furthermore, if the steepness of di/dt is greater, this value will be increased. In order to keep this dynamic voltage drop low, the inductance of the connecting cable and hence its length must be kept as low as possible (less then 0.5 m).

SPDs in the AC power installation

Due to short distance between entry point of the cables and the equipment in the vault combined lightning current and surge arresters (Type 1 +Type 2 SPD in a single unit) are recommended when low impedance equipotential bonding from the protective device to the terminal device can be assured (e.g. use shielded cable from combined arrestor to the terminal device).



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When using separate Type 1 and Type 2 SPD in series, coordination of the SPDs is essential to ensure proper share of the surge energy among the involved SPDs. Manufacturers of SPD offer coordinated product lines and provide information about installation requirements (e.g. minimum cable length between Type 1 and Type 2 unit). Coordination with the local power distribution network operator is required to ensure installation of surge protection devices in line with local regulations and conditions (e.g. before or after the meter or different solutions are applicable in TN, TT or IT distribution network systems).

With respect to system earthing (TT, TN, IT) and position of Residual Current Device (RCD) the SPDs shall be installed as shown in Figure 27, Figure 28, and Figure 29, respectively [13], unless it contradicts local regulations. The main target is to ensure proper operation of the RCD even in case of a damaged SPD.

Figure 27: Installation of SPD in TN-system

Figure 28: Installation of SPD in TT-system

1 Origin of the installation 2 Distribution board 3 Main earthing terminal or bar 4 Surge protective devices 5 Earthing connection of surge protective

devices, either location 5a or 5b 6 Equipment to be protected F Protective device indicated by the

manufacturer of the SPD (for example, fuse, circuit-breaker, RCD)

RA Earthing electrode (earthing resistance) of the installation

Rg Earthing electrode (earthing resistance) of the supply system

1 Origin of the installation 2 Distribution board 3 Main earthing terminal or bar 4 Surge protective devices 4a Surge protective device in accordance with

IEC 60364-5-53 (2.3.2) or spark gap 5 Earthing connection of surge protective

devices, either location 5a or 5b 6 Equipment to be protected 7 Residual current protective device (RCD) F Protective device indicated by the






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Figure 29: Installation of SPD in IT-system

SPDs in Telephone/Control/Data Network Circuits and RF installations

Lightning equipotential bonding requires that all metal conductive components such as cable lines and shields at the entrance to the building shall be incorporated into the equipotential bonding to achieve impedances as low as possible. Examples of such components include antenna lines, telecommunication and control lines with metal conductors. The lines are connected with the help of elements capable of carrying lightning current (arresters and shielding terminals). A convenient installation site is the point where cabling enters the building. Both the arresters and the shielding terminals must be chosen to be appropriate to the lightning current parameters to be expected.

The individual cables must be integrated into the equipotential bonding as follows:

Unshielded cables must be connected by SPDs which are capable of carrying partial lightning currents (the expected partial lightning current per wire is the partial lightning current of the line divided by the number of individual wires).

If the cable shield is capable of carrying lightning currents, the lightning current flows via the shield. However, capacitive/inductive interferences can reach the wires and make it necessary to use surge arresters.

o The shield at both ends must be connected to the main equipotential bonding to be capable of carrying lightning currents

1 Origin of the installation 2 Distribution board 3 Main earthing terminal or bar 4 Surge protective devices 5 Earthing connection of surge protective

devices, either location 5a or 5b 6 Equipment to be protected 7 Residual current protective device (RCD) F Protective device indicated by the






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Figure 30: Shield connection system capable of carrying lightning currents

Whenever possible all outside equipment (antennas, sensors, etc.) shall be installed in LPZ 0B.

When implementing measures to protect against disturbance variables from nearby, distant and direct lightning strikes, it is recommended to apply a concept of protective devices with several protective stages. This reduces the high energy interference (partial lightning current) in stages because an initial energy absorbing stage (LPZ 0/LPZ 1) prevents the main part of the interference from reaching the downstream system. The subsequent stages (LPZ 1/LPZ 2) serve to reduce the interference to values which the system can cope with.



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3 CTBTO/IMS Specific Part

This part is a complement to section 2 and describes specific requirements for the protection of IMS field installations. The protection of the Central Recording Facility (CRF) and the remote elements is discussed, as well as some technology specific issues.

3.1 Classification of CTBTO/IMS stations

3.1.1 Classification in terms of lightning exposure

The CTBTO/IMS stations are installed at geographical locations with different exposure to lightning. With respect to their location, the stations can be separated in two classes, Class A and Class B.

Class A: Lightning Exposed

Lightning is not an unusual event in the region and therefore all protection measures (SPDs, equipotential bonding, etc.) should consider direct lightning on site or to an entering service (e.g. use SPD Type I at the entry points of service lines and install a lightning protection system).

In terms of the Lightning Protection Level (LPL) defined and used in IEC 62305 a LPL II should be considered as a standard for Class A CTBTO/IMS stations, since there is no risk of explosions and loss of human life involved in IMS stations.

Class B: None or very little lightning activity

Lightning is not expected in the region or is an extraordinary event. Extra lightning protection is not necessary but typical measures for surge protection and equipotential bonding as for Class A sites are recommended with the only difference that installation of SPDs Type 2 (see section 2.2.5.8) at the entry point of service lines is sufficient.

As for many sites reliable data of ground flash density or annual thunderstorm days are not available to the public, the classification should be based also on information from local authorities.

Class B should be used only, when the local authorities confirm the absence of any lightning activity. The budget differences in the protection measures for Class A and Class B stations are relatively small compared to the total value of installed equipment. The consequences of increased failure rate and costs for repair do hardly justify the acceptance of any lightning risk.

3.1.2 Classification in terms of Lightning Protection Zones

For a typical CTBTO/IMS site application of LPZ 0A, LPZ 0B, LPZ 1 seems sufficient with the following specifications:



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LPZ 0A: Exterior of the site

LPZ 0B: Outside areas protected against direct lightning strikes either by extra lightning rods or by IMS station construction elements (e.g. radio tower)

LPZ 1: Inside the equipment vault or the CRF At the boundary LPZ 0A to LPZ 1 lightning current arrestors (Type 1 SPD) shall be

used whereas at the boundary LPZ 0B to LPZ 1 surge arrestors (Type 2 SPD) shall be used.

When the expected lightning strike rate is very high, implementation of LPZ 2 inside the CRF building is highly recommended.

3.2 Protection of the Central Recording Facility

CRF is usually located in a separate building or in a dedicated room of an existing building. The design of the LPS for the CRF installation has to comply with standard IEC 62305, LPL II.

3.2.1 Air Termination system and down-conductors

Typical design of the air termination and down conductor system of a small building with two down conductors placed at diagonal corners is shown in Figure 31.

Figure 31: Typical external LPS of a small building

Alternatively to the system of horizontal air termination conductors shown in Figure 31 protection can also be achieved by vertical lightning rods of a sufficient height to place the building within the protected volume.

3.2.2 Earth termination system

Foundation earth electrodes shall be the preferred earth electrode system for buildings. When professionally installed, electrodes are enclosed in concrete on all sides, and hence, corrosion resistant. Because of the large area of this type of



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electrode, low earthing resistance can be achieved. The hygroscopic characteristics of concrete generally produce a sufficiently low earth electrode resistance.

The foundation earth electrode must be installed as a closed ring in the strip foundation or the bedplate and thus also acts primarily as the equipotential bonding (Figure 32, Figure 33). For larger buildings (exceeding dimensions of 20 m) a division into meshes ≤ 20 m x 20 m is required. The terminal lugs to the outside required to connect the down conductors of the external lightning protection system, and to the inside for equipotential bonding, must be considered.

Figure 32: Preparation of foundation earth electrode (spaces ensure that electrodes are

enclosed on all sides by concrete)

Figure 33: Foundation earth electrode in use

Terminal lugs to the outside into the ground must have supplementary corrosion protection at the outlet point. Suitable materials are, for example, plastic sheathed steel wire high-alloy stainless steel, Material No. 1.4571, or fixed earthing terminals.

When a foundation earth electrode is not possible, a ring electrode shall be installed. When choosing the material of the earth electrode with regard to corrosion, the local conditions must be taken into consideration. It is advantageous to use stainless steel.

In case of CRF being located in a dedicated room of an existing building, whose earth termination system does not comply with LPL II requirements, an upgrade of the earth termination system according to LPL II is required.

3.2.3 Equipotential bonding system

Equipotential bonding shall be done according to section 2.2.4.

3.2.4 Surge protection

All incoming and outgoing cables must be protected at the entrance of the building (LPZ 0A,B / LPZ 1 – boundary) by appropriate SPDs.

When LPZ 2 needs to be provided, the CRF equipment must be installed in a metal rack which defines the volume of the LPZ 2. Appropriate SPDs shall be installed at all lines crossing this boundary



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Special attention should be paid also to equipment not belonging to IMS station but is interconnected through power or signal connections with the IMS station equipment.

In case of a dedicated room, the room boundaries define the LPZ 1 volume and appropriate SPDs shall be installed at all lines crossing this boundary.

3.3 Protection of the remote elements

The remote elements shall be protected from direct lightning and lightning induced surges based on the lightning protection zones concept. The main equipment shall be located in the LPZ 1. Some units, located outside, will be situated in the LPZ 0B (antennas and radio modems) and no equipment shall be installed in the LPZ 0A.

The protection zones at remote elements are shown in Figure 34 and Figure 35. The boundary between LPZ 0A and LPZ 0B is defined by the protection zones, calculated for the LPL II, provided by the communication towers, power transmission line poles or installed lightning attractors. The LPZ 0B and LPZ 1 boundary is defined by the SPDs at the entrance to the equipment vault.

Figure 34: Example for LPZ for an infrasound remote element (Note: it is assumed in this example that trees provide certain protection against direct strikes to installations at ground

level)



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Figure 35: Example of LPZ for a seismic remote element

A schematic LPZ concept and according SPD installations for a remote element is shown in Figure 36. All lines entering the equipment vault are protected by SPDs and the GPS antenna and meteorological sensors are placed in LPZ 0B.

Figure 36: Lightning protection concept of an IMS station (schematic)

3.3.1 Air termination system

All electronic equipment, including solar panels, GPS and RF antennas, and meteorological stations, installed at remote elements shall be located within LPZ 0B.



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This zone LPZ 0B is provided either by existing installations (e.g. radio tower) or extra installed lightning protection rods. Protection angles are computed according to LPL II (see section 2.2.1).

Figure 37: Example of air-termination for RF antenna at an IMS station

3.3.2 Down-conductors

Down-conductors are not required, except in case of lightning air-termination installed on non conductive structures (e.g. wooden or fiber glass masts). When such non conductive structures are used, the size and material of the down conductor shall comply with requirements in section 2.2.2.

3.3.3 Earth-termination system

The earthing of the remote elements should be designed in order to provide (a) equipotential plane and (b) low resistance to ground. Figure 38 and Figure 39 present two examples for a recommended design of the earthing system for CTBTO/IMS array elements. As the size, the distances and the relative position between the tower, the equipment vault and the fences may vary from site to site, the following main aspects should be considered:



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Figure 38: Example of schematic design of earth termination system for an IMS infrasound array element. A minimum of 4 earthing rods per structure (communication tower, equipment

vault, and solar panel array) shall be installed



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Figure 39: Example of schematic design of earth termination system for an IMS seismic array element. A minimum of 4 earthing rods per structure (communication tower, equipment vault,

and solar panel array) shall be installed



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Create one integrated earthing systems for the tower and equipment vault (about 5 m x 5 m mesh)

Ring conductor (distance about 1 m) around the tower and the equipment vault shall be used in order to provide control of the step voltage in the vicinity of the constructions

Vertical ground rods shall be used when they result in a significant and cost effective reduction of earthing resistance (e.g. when they reach the ground water level or other good conduction soil layers).

Ensure low impedance connection between tower and vault and/or building parallel to the cables.

To minimize potential differences all metal parts (e.g. tower base, guy wires, GPS and meteorological mast, solar panel frames, conductive fences, borehole casing, etc.) shall be connected to the earth termination system. Material and dimension shall be selected according to section 2.2.3.1

3.3.4 Equipotential Bonding system

The equipotential bonding at the remote elements has to be done according to section 2.2.4 by the installation of SPDs at all incoming and outgoing cables and proper connection of cable shields at the cable entry point, as well as equipment chassis interconnection.

To reduce the potential difference between the tower and the vault the following may be applied:

Several parallel bonding conductors running in the same paths as the electrical cables, or the cables enclosed in grid-like reinforced concrete ducts (or continuously bonded metal conduit), which have been integrated into both of the earth-termination systems.

Shielded cables with shields of adequate cross-section, and bonded to the separate earthing systems at either end.

Cables shall be placed inside the tower structure whenever possible (reduces induction effects).



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Figure 40: Preferential cable routing along a tower of triangular cross profile

3.3.5 Surge Protection

The Surge Protective Devices (SPD) shall be installed according to section 2.2.5 at the entrance of all incoming cables to the equipment vault (boundary of the LPZ 0B to LPZ 1). Examples are shown in Figure 36 and Figure 41.

Figure 41: Example of SPDs installed at the entrance of incoming cables to the equipment vault

3.4 Technology Specific Situations

3.4.1 Seismic Monitoring Stations

The main specific part of the seismic monitoring station is the existence of the borehole (up to a depth of 60 m or more) at the remote elements. The casing of this borehole must be integrated to the earth termination system. It should be noted, that this casing does not substitute the earth termination system described above.



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Figure 42: Borehole at an IMS seismic monitoring station with earthing conductor

3.4.2 Infrasound Monitoring Stations

The main specific part of the infrasound monitoring station is the existence of wind noise reducing pipe array (see Figure 43) at the remote elements. In case of an electrically conductive pipe array it must be integrated to the earth termination system. It should be noted, that this does not substitute the earth termination system described above.

Figure 43: Pipe array at an infrasound station, partly filled by soil

3.4.3 Hydroacoustic Monitoring Stations

The protection requirements for Hydroacoustic (Hydrophone) stations are covered by the requirements for CRF. No specific situation is foreseen for T-Phase Monitoring Stations.



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3.4.4 Radionuclide Monitoring Stations

No specific requirements apply to radionuclide monitoring stations. Any buildings and objects shall be protected by a lightning protection system of LPL II according to IEC 62305-3 standard. Air sampler and meteorological sensors shall be placed in the protected area of the air termination system or protected structure (LPZ 0B) to avoid direct strikes to the technical equipment. Surge protection on power lines and data lines shall be installed at the interfaces of the LPZs. An example of a lightning protection system for a radionuclide monitoring station is shown in Figure 44.

Figure 44: Lightning protection of a radionuclide monitoring station by a metallic tower providing protected volume for the satellite antenna



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Annex A Maintenance and inspection of the Lightning Protection System

A.1 General

The objective of the LPS inspections is to ascertain that:

the LPS conforms to the originally specified design, all components of the LPS are in good condition and capable of performing

their designed functions, and that there is no corrosion, and that any recently added services or constructions are incorporated into the LPS.

Inspections should be made:

during the construction of the structure, in order to check the embedded electrodes that will become inaccessible;

after the installation of the LPS; periodically at intervals determined with regard to the nature of the structure to

be protected, i.e. corrosion problems and the class of LPS; after alterations or repairs, or when it is known that the structure has been

struck by lightning.

During the periodic inspection, it is particularly important to check the following:

deterioration and corrosion of air-termination elements, conductors and connections;

corrosion of earth electrodes; earthing resistance value for the earth-termination system; condition of connections, equipotential bonding and fixings.

A.2 Recommended frequency of inspection

For class II LPS a visual inspection at least annually is recommended in IEC 62305-3. A complete inspection (including measurements and component tests) is recommended every 2 years.

A.3 Visual inspection

Visual inspections should be made to ascertain that:

the LPS is in good condition, there are no loose connections and no accidental breaks in the LPS

conductors and joints, no part of the system has been weakened by corrosion, especially at ground

level, all visible earth connections are intact (functionally operational),



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all visible conductors and system components are fastened to the mounting surfaces and components which provide mechanical protection are intact (functionally operational) and in the right place,

there have not been any additions or alterations to the protected structure which would require additional protection,

there has been no indication of damage to the LPS, to SPDs or any failures of fuses which protect SPDs,

correct equipotential bonding has been established for any new services or additions which have been made to the interior of the structure since the last inspection, and that continuity tests have been performed for these new additions bonding conductors and connections inside the structure are present and intact (functionally operational),

separation distances are maintained, bonding conductors, joints, shielding devices, cable routing and SPDs have

been checked and tested.

A.4 Testing

Visual inspections should be completed by the following actions:

Performing continuity tests, especially continuity of those parts of the LPS which were not visible for inspection during the initial installation and are not subsequently available for visual inspection;

Conducting earth resistance tests of the earth-termination system. The following isolated and combined earth measurements and checks should be made and the results recorded in an LPS inspection report:

(1) The resistance to earth of each local earth electrode and where reasonably

practical the resistance to earth of the complete earth-termination system. Each local earth electrode should be measured in isolation with the test point

between the down-conductor and earth electrode in the disconnected position (isolated measurement).

If the resistance to earth of the earth-termination system as a whole exceeds 10 Ω, a check should be made to ascertain that the electrode conforms to the minimum length requirements of Figure 9.

If there is a significant increase in the value of the earth resistance, additional investigations should be made to determine the reason for the increase and measures taken to improve the situation.

For earth electrodes in rocky soil, the requirements in section 2.2.3.5 should be followed. The 10 Ω requirement is not applicable in this case.

(2) The results of a visual check of all conductors, bonds and joints or their

measured electrical continuity.



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Annex B Soil resistivity measurements

B.1 Specific earth resistance ρE

ρE is the specific electrical resistance of the soil. It is typically given in units Ohm.m (Ωm) and represents the resistance between two opposite sides of a cube of soil with edges of 1 m in length (see Figure 45).

Figure 45: Definition of specific ground resistivity ρE

Note: In some documents the term ground conductivity σE, given in units Siemens/meter (S.m-1), is used and is defined as the inverse of the ground resistivity σE = 1/ ρE.

The specific earth resistance ρE which determines the magnitude of the earth electrode resistance RA of an earth electrode is a function of the composition of the soil, the amount of moisture in the soil and the temperature. It can fluctuate between wide limits. Values and fluctuation ranges of the specific earth resistance ρE for various types of soil are given in Figure 46.



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Figure 46: Specific earth resistance ρE of different ground types

B.2 Seasonal fluctuations

Extensive measurements have shown that the specific earth resistance varies significantly depending on the burial depth of the earth electrode. Owing to the negative temperature coefficient of the ground (α = 0.02 ... 0.004), the specific earth resistance attain a maximum in winter and a minimum in summer. It is therefore advisable to convert the measured values obtained from earth electrodes to the maximum prospective values, since even under unfavorable conditions (very low temperatures) permissible values must not be exceeded. The curve of the specific earth resistance ρE as a function of the season (ground temperature) can be represented to a very good approximation by a sinus curve having its maximum at the northern hemisphere around the middle of February and its minimum around the middle of August. Investigations have further shown that, for earth electrodes buried not deeper than around 1.5 m, the maximum deviation of the specific earth resistance from the average is around ± 30 % (see Figure 47).

Figure 47: Specific earth resistance ρE as a function of the seasons without influencing of rainfall (burial depth of the earth electrode < 1.5 m). Note: This figure is valid for mid

latitudes at the northern hemisphere. Shifting the x-axis by six month it can be applied to the southern hemisphere too



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For earth electrodes buried deeper (particularly for earth rods), the fluctuation is merely ± 10 %. From the sine - shaped curve of the specific earth resistance in Figure 47 the earthing electrode resistance RA of an earth-termination system measured during a particular season can be converted to a maximum prospective value.

B.3 Measurement of specific earth resistance ρE [8], [10]

The specific earth resistance ρE is determined using an earthing measuring bridge with 4 clamps. Figure 48 illustrates the measuring arrangement of this measuring method named after WENNER. The measurement is carried out from a fixed central point M which is retained for all subsequent measurements. Four measuring probes (earthing spikes 30 ... 50 cm long) are driven into the soil along a line a – a' pegged out in the ground. From the measured resistance R one can determine the specific earth resistance ρE of the ground:

Figure 48: Determination of the specific earth resistance ρE with a four-terminal measuring

bridge according to the WENNER method. Current I is injected by electrodes A, B and voltage drop U along the central earth section between electrode M and N is picked off by

electrodes M, N

R measured resistance (R=U/I) in Ω e probe distance in m ρE average specific earth resistance in Ωm down to a depth corresponding to

about the probe distance e

By increasing the probe distance e (e.g. stepwise from 2 m to 30 m) and retuning the earthing measuring bridge, the curve of the specific earth resistance ρE as a function of the depth can be determined (examples see Figure 49).



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Curve 1: A decrease of ρE with increasing depth (see line “1” in Figure 49) indicates existence of good conductive soil layer (ground water) at greater depth and a deep earth electrode is advisable.

Curve 2: As ρE decreases only down to point Z, an increase in the depth deeper than Z does not improve the values.

Curve 3: With increasing depth ρE is not decreasing: a strip conductor electrode is advisable

Figure 49: Specific earth resistance ρE as a function of probe distance “e”

As measuring results are often distorted and corrupted by underground pieces of metal, underground aquifers etc, a second measurement, in which the spike axis is turned by an angle of 90°, is always advisable (see Figure 50).

Figure 50: 90° turned positions of earth electrodes to check for any underground pieces of metal



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Annex C Earthing Electrode System Testing/Verification

Procedures in this section shall not be performed by untrained or unqualified personnel, nor are any procedures herein intended to replace proper training. It is required that personnel attempting to measure the resistance of an earthing electrode system receive prior formal training on the subject and on its associated safety hazards. All

applicable laws, rules and codes regulating the work on electrical systems shall be complied with at all times.

This section provides procedures for performing resistance testing of the site earthing electrode system. The resistance of an earthing electrode system shall be measured after its installation and before it is bonded to the power company neutral wire or any other utility, such as the telephone ground or metallic pipes.

Periodic testing shall be performed on the site regularly when the site ground system can be safely disconnected from the power company neutral wire. Suggested best practice is to perform the test at least once every year, with tests being performed in alternate seasons to verify results under diverse soil moisture/temperature conditions.

NOTE: Earthing electrode system testing shall be performed anytime the site is suspected to have taken a direct lightning strike.

C.1 Overview

Testing shall be performed using one of the methods which are described in this chapter. The methods are:

C.2 3-pole/4-pole Measurement of Earthing Resistance

This method is the most widely accepted. However, performing the test may require access to areas that may be beyond the site property lines.

The current voltage measuring method is based on the block diagram circuit shown in Figure 51 below.



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Figure 51: Earthing Resistances Measurement - Method

An AC generator G feeds current I via earth electrode E (earth electrode resistance RE) and auxiliary earth electrode H (auxiliary earth electrode resistance RH).

Voltage UE drops on earthing resistance RE (UE proportional to RE.) This voltage is picked up and measured by probe S. With the so called three wire circuit, the instrument sockets E and ES are connected to each other.

In a four wire circuit a separate cable is used to connect socket ES with the earth electrode and with that, the voltage drop of the cable between socket E and earth electrode is not measured. As the voltage measuring circuit has such a high impedance, the influence by the probe resistance RS is negligible within certain limits.

Thus the earthing resistance RE evolves

I

UR meas

E

and is independent from the resistance of the auxiliary earth electrode RH. The generator typically runs at a frequency between 70 and 140 Hz.

A probe positioned inside a potential gradient area leads to incorrect measuring results. For that reason it is advisable to repeat each measurement with repositioned probes and only to regard a measurement as successful and accurate if several subsequent measurements result in the same values. Normally, a distance of 20 m to the earth electrode and to the probes to each other is sufficient (see Figure 52).



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Figure 52: 3-pole/4-pole Measurement of Earthing Resistance - Process

An accuracy test of the results is made with another measurement following repositioning of the auxiliary earth electrode or probe. If the value stays about the same, the distance is sufficient. If the measured value changes, probe or auxiliary earth electrode must be repositioned until the measured value RE stays constant. Spike wires should not run too close to each other.

C.3 Clamp-on Ohmmeter

This method shall be used when access to necessary space needed for the 3-pole/4-pole Measurement of Earthing Resistance is not available. However, the clamp-on ohmmeter test can only be performed after AC utilities have been connected to the site and various feed conductors are accessible.

The Clamp-on Ohmmeter works on the basis of injecting a known voltage U into the earthing electrode system in order to create a current flow whose value is a function of the earthing electrode system resistance. The test current flows from the earthing electrode system through the earth, returning to the earthing electrode system via the power company’s multi-grounded neutral wire.

The meter then measures this current and converts the measurement to a resistance reading using Ohm’s Law (R = U/I). As such, the meter displays a resistance of the earthing electrode system in Ohms. Since the power company’s earthing system is so extensive, the meter considers it to be of negligible value and disregards its effect on the reading.

The test voltage (U) is applied without disconnecting ground rod and/or the direct electrical connection by means of a clamp-on current transformer and the current detected by a second current transformer (some companies provide meters where the two transformers are combined in a single instrument).



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Figure 53: Clamp-on Ohmmeter Measurement of Earthing Resistance (RX Earthing Resistance to be measured, R 1… Rn

It is recommended that the commercial power be turned off in order to eliminate any currents on the neutral wire that can affect the meter’s ability to give an accurate reading of RX.

Figure 54: Placement of Clamp-on Ohmmeter

C.4 Prerequisites for Testing

The following conditions must be met in order to perform earthing electrode system testing:



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(1) 3-pole/4-pole Measurement of Earthing Resistance is possible only if the following conditions can be met:

Sufficient land area must be available to perform 3-pole/4-pole Measurement of Earthing Resistance. The reference probe may likely need to be inserted into soil that is beyond the site fence or property line. Testing using a clamp-on ohmmeter may be an option in these cases.

The earthing electrode system must be able to be isolated from the power company grounded conductor (may be a neutral wire).

(2) Clamp-on Ohmmeter testing is possible only if the following conditions can be met:

Site must be supplied with commercial power company-provided power. Sites supplied only by a generator or other non-commercial power may not be suitable for clamp-on ohmmeter testing.

Neutral wire must be present as part of the power company service.

Neutral wire must be part of an extensive power company earthing system. In systems such as 3-phase delta service, the neutral wire may not be part of the extensive power company earthing system.

The earthing electrode system must be connected to the power company grounded conductor (may be a neutral wire).

For sites using a multi-bonded/multi-earthing electrode system (such as commonly used at communications sites), a point on neutral wire for meter to clamp onto must be available before its first bond to the site.

For a single earthing electrode system, the earthing electrode conductor must be accessible for the meter to clamp onto at a point between the earthing electrode and any other connection (such as the telephone company ground or a metallic pipe).

(3) Combined Soil Resistivity/Clamp-on Ohmmeter testing is possible only if the following conditions can be met:

System must be such that gathering of individual earthing electrode system component values with a clamp-on-ohmmeter can be available for use by an engineering firm.

A soil resistivity profile for the site has been performed and is available for use by an engineering firm.

If these conditions cannot be met, an added supplemental earthing electrode system can be installed. This supplemental earthing electrode system could be installed and tested prior to its connection to the existing system. This supplemental system should be installed in such a manner as to allow an easy disconnect point for future testing.



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C.5 Required Test Equipment and Supplies

Ground Resistance Tester (with supplied test leads, test clips, and probes)

Small sledgehammer

Tape measure

Safety glasses

Gloves

Earthing/Bonding System Test Worksheet (Table 15)



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Table 15: Earthing/Bonding System Test Worksheet

Test completed by:

Date:

Client/Project:

Site Location/ID:

Ground Resistance Tester

Model: S/N:

Calibration date:

Soil Description

Ambient Conditions during test

Temperature: Present conditions (dry, rain, snow): Date of last precipitation:

Documentation available to the person performing the test:

Documentation of the earthing system

Test results of the previous test

Type of Test:

Initial Test after completion

Scheduled test after …. Years

Unscheduled test after a lightning strike

………………………………………………..

Material(s) used for earthing/earthing system (result of visual inspection)

Copper

Stainless steel

Galvanized steel

o.k

not o.k

Results of measurement:

Specific Ground Resistivity (ρ): ……………….(Ωm)



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Individual earthing rods:

# 1 2 3 4 5 6

RE (Ω)

Comments:



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Annex D Dissimilar Metals and Corrosion Control

Components of an LPS shall withstand the electromagnetic effects of lightning current and predictable accidental stresses without being damaged. Components of an LPS shall be manufactured from the materials listed in Table 16 or from other materials with equivalent mechanical, electrical and chemical (corrosion) performance.

Table 16: LPS materials and conditions of use [3]

Earth electrodes made of a uniform material can be threatened by corrosion from corrosive soils and the formation of concentration cells. The risk of corrosion depends on the material and the type and composition of the soil.

The pH (hydrogen ion concentration) of the soil where an earthing electrode system is to be installed should be tested before the system is installed.

Test soil pH using a commercially available soil pH meter or a swimming pool acid/ base tester. If using a swimming pool acid/base tester, mix and test a solution containing one part site soil and one part distilled water. In strongly acidic soils (pH of



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5 or below), it is recommended that precautionary measures be taken to help maintaining the life expectancy of the earthing electrode system.

Some options may be as follows: • Consult an engineering firm • Encase all earthing electrode system components in an earthing

enhancing material • Use stainless steel or solid copper ground rods instead of copper-clad

rods.

D.1 Choice of earth electrode materials

Table 6 is a compilation of the earth electrode materials and minimum dimensions usually used.

D.1.1 Hot-dip galvanized steel

Hot-dip galvanized steel is also suitable for embedding in concrete. Foundation earth electrodes, earth electrodes and equipotential bonding conductors made of galvanized steel in concrete may be connected with reinforcement iron.

D.1.2 Bare steel

Bare steel shall be used only when completely embedded in concrete. When bare steel (not embedded in concrete) is already in use in existing installations corrosion effects over the years should be monitored carefully.

D.1.3 Steel with copper sheath

In the case of steel with copper sheath, the comments for bare copper apply to the sheath material. Damage to the copper sheath, however, creates a high risk of corrosion for the steel core; hence a complete closed copper layer must always be present.

D.1.4 Bare copper

Bare copper is very resistant due to its position in the electrolytic insulation rating. Moreover, in combination with earth electrodes or other installations in the ground made of more “base” materials (e.g. steel), it has additional cathodic protection, although at the expense of the more “base” metals.

D.1.5 Stainless steels

Certain high-alloy stainless steels (e.g. V4A) are inert and corrosion-resistant in the ground. The free corrosion potential of high-alloy stainless steels in normally aerated soils is mostly close to the value of copper.

As the surface of stainless steel earth electrode materials is passivating within a few weeks, they are neutral to other more inert and base materials.



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Stainless steels shall contain at least 16 % chrome, 5 % nickel and 2 % molybdenum. Extensive measurements have shown that only a high-alloy stainless steel with the Material No. 1.4571, for example, is sufficiently corrosion-resistant in the ground.

D.2 Combination of earth electrodes made of different materials

No combination of materials shall be used that will form an electrolytic couple of such a nature that, in the presence of moisture, corrosion will be accelerated. In those cases where it is impractical to avoid a junction of dissimilar metals, the corrosion effect shall be reduced by the use of plating or special connectors, such as stainless steel connectors used between aluminum and copper or copper alloys.

The cell current density resulting from the combination of two different metals installed in the earth to be electrically conductive, leads to the corrosion of the metal acting as the anode. This essentially depends on the ratio of the magnitude of the cathodic area AC to the magnitude of the anodic area AA. A higher degree of corrosion is only to be expected if the ratio of the areas is

100A

C

A

A.

Table 17 shows possible combinations (+) of materials and not combinable (-) materials when AC > 100 x AA.

Table 17: Material combinations of earth-termination systems for different area ratios

(AC > 100 x AA)



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D.3 Methods to help reduce Corrosion

D.3.1 Galvanized steel connecting cables from foundation earth electrodes to down conductors

Galvanized steel connecting cables from foundation earth electrodes to down conductors shall be laid in concrete or masonry up to above the surface of the earth. If the connecting cables are led through the ground, galvanized steel must be equipped with concrete or synthetic sheathing or, alternatively, terminal lugs with NYY cable, stainless steel or fixed earthing terminals must be used. Within the masonry, the earth conductors can also be led upwards without corrosion protection.

D.3.2 Earth entries

Earth entries made of galvanized steel must be protected against corrosion for a distance of at least 0.3 m above and below the surface of the earth (Figure 55). Generally, bitumen coatings are not sufficient. Sheathing not absorbing moisture offers protection, e.g. butyl rubber strips or heat-shrinkable sleeves.

Figure 55: Points threatened by corrosion [8] and practical solution

D.3.3 Underground terminals and connections

Cut surfaces and connection points in the ground must be designed to ensure that their corrosion resistance is as good as the corrosion resistance of the basic earth electrode material. Therefore it might be necessary (e.g. when there is a cut of galvanized steel), to cover that connection points in the ground with a suitable coating, e.g. sheathed with an anticorrosive band.



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Annex E Lightning Protection System Compliance Matrix

CTBTO guidelines minimum requirements Reference Station Design Remarks

AIR TERMINATION SYSTEM

Design Parameters

Rolling sphere radius: 30m Mesh size: 10 m x 10 m Protection angle: see Table 2 of IEC 62305-3

IEC 62305-3, Table 2

Air termination system material

Galvanized steel Stainless steel Copper Aluminum


Air termination conductors diameter/cross-section

Galvanized steel: solid round Ø8 mm or cross section 50 mm2 Stainless steel: solid round Ø8 mm or cross section 50 mm2 Copper: solid round Ø8 mm or cross section 50 mm2 Aluminum: solid round Ø8 mm or cross section 50 mm2




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DOWN CONDUCTORS

Design Parameters

Maximum distance between down-conductors 10 m IEC 62305-3, Table 4

Minimum number of down conductors

Two (2) IEC 62305-3, 5.3

Down conductor material

Copper Aluminum Galvanized steel Stainless steel


Down conductors diameter/cross-section

Galvanized steel: solid round Ø8 mm or cross section 50 mm2 Stainless steel: solid round Ø8 mm or cross section 50 mm2 Copper: solid round Ø8 mm or cross section 50 mm2 Aluminum: solid round Ø8 mm or cross section 50 mm2




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EARTH TERMINATION SYSTEM

Design Parameters

For the specific soil resistivity up to 800 Ωm: Horizontal electrodes: 5.0 m Vertical electrodes: 2.5 m

IEC 62305-3, Figure 2

Earth termination system material

Copper Galvanized Steel Stainless steel


Earth rod diameter Copper solid round: Ø 15 mm Galv. steel solid round: Ø 16 mm Stainless steel solid round: Ø 15 mm


Earth conductor cross-section

Copper: 50 mm2 Galv. steel: 90 mm2 Stainless steel: 100 mm2


Earthing resistance of the earth-termination system

Recommended < 10 Ω IEC 62305-3, 5.4.1



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LPL class II minimum requirements Reference Station Design Remarks

EQUIPOTENTIAL BONDING

Main bonding bar (MBB)

Placed close to the entry point of service lines

Conductors connecting bonding bar to earth termination system

Copper 14 mm2 Aluminum 22 mm2 Steel 50 mm2


Conductors connecting internal metal installations to the bonding bar

Copper 5 mm2 Aluminum 8 mm2 Steel 16 mm2


Bonding of AC power line by SPD (Typ1 or Type 2) IEC 62305-3, 6.2.5

Bonding of data and communication lines by SPD IEC 62305-3, 6.2.5

Bonding of cable shields directly to MBB IEC 62305-3, 6.2.5



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LPL class II minimum requirements Reference Station Design Remarks

SURGE PROTECTION

AC Power supply Type 1+2 SPD1 IEC 62643-12

Photovoltaic system Type 1+2 SPD EN 65305-3

GPS antenna

Place antenna within protected area of air termination rod (LPZ 0B) IEC 62305-1

SPD for RF coaxial cable, Type 2, with protective effect P1, for installation at the boundary LPZ 0B/LPZ 1. Bandwidth must be suitable for GPS signal (carrier frequency of 1575 MHz). Operating DC voltage up to 8 V is necessary for active GPS antennas.

IEC 61643-21

EN 61000-4-5

1 Installation requirements depend on local power network type (e.g. TT, TN system)



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SURGE PROTECTION cont.

RF antenna

Place antenna within protected area of air termination rod (LPZ 0B) IEC 62305-1

SPD for RF coaxial cable, Type 2, with protective effect P1, for installation at the boundary LPZ 0B/LPZ 1. Bandwidth must correspond to RF equipment specifications.

IEC 61643-21

EN 61000-4-5

Meteorological data

Place sensors within protected area of air termination rod (LPZ 0B). IEC 62305-1

SPD for data lines, discharge capacity Type 2, with protective effect P1, for installation at the boundary LPZ 0B/LPZ 1, corresponding to the signal parameters of the sensors.

IEC 61643-21

EN 61000-4-5

Signal cables

SPD for data lines, discharge capacity Type 2, with protective effect P1, for installation at the boundary LPZ 0B/LPZ 1, corresponding to the type of the signal.

IEC 61643-21

EN 61000-4-5



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Annex F List of Abbreviations

α Protection angle of air-terminal (°) Ad Collection area of structure for direct strikes Am Collection area of structure for nearby strikes CRF Central Recording Facility LPS Lightning protection system LEMP Lightning electromagnetic impulse LPZ Lightning protection zone Nd Annual number of direct strikes to a structure Ng Ground flash density Nm Annual number of nearby strikes to a structure Ni Annual number of strikes nearby an incoming line NL Annual number of direct strikes to an incoming line PE protective earthing conductor PEN PEN conductor is a conductor combining the functions of both a

protective earthing conductor and a neutral conductor RA Earth electrode resistance (Ω) RCD Residual Current Device ρ Specific earth resistivity (Ωm) σE Specific ground conductivity (Sm-1) SPD Surge protective device Td Thunderstorm days per year Th Thunderstorm hours per year TOV Temporary over voltage (V) UC Maximum continuous operation voltage (V) UP Voltage protection level of a SPD VOC STC Open circuit voltage of a PV module at Standard Test Conditions (V)



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Annex G References

[1] IEC 62305-1:2006-01, Protection against lightning - Part 1: General principles [2] IEC 62305-2:2006-01, Protection against lightning - Part 2: Risk management [3] IEC 62305-3:2006-01, Protection against lightning - Part 3: Physical damage to structures

and life hazard [4] IEC 62305-4:2006-01, Protection against lightning - Part 4: Electrical and electronic

systems within structures [5] F. de la Rosa, K. Cummins, L. Dellera, G. Diendorfer, A. Galván, J. Husse, V. Larsen,

C.A. Nucci, F. Rachidi, V. Rakov, H. Torres and M.A. Uman: Characterization of lightning for applications in Electric Power Systems, Technical Brochure No.172, CIGRE WG. 33.01.02, December 2000.

[6] IEEE Std 1410-2004, IEEE Guide for Improving the Lightning Performance of Electric Power Overhead Distribution Lines

[7] Driven Ground Rod 1-3-7 Year Test Program”, Final Report, Draft No. 2 September 1971, National Association of Corrosion Engineers

[8] Lightning Protection Guide (2nd updated edition) – Dehn + Söhne, 2007 [9] IEC 60728-11:2005 Cable networks for television signals, sound signals and interactive

services - Part 11: Safety, 2005 [10] FLUKE 1625 Earth/Ground Tester. Users Manual, 2006 [11] IEC TR 62066: Surge overvoltages and surge protection in low-voltage a.c. power

systems – General basic information, First edition 2002 [12] IEC 61643-1: Low-voltage surge protective devices - Part 1: Surge protective devices

connected to low-voltage power distribution systems - Requirements and tests. Ed.2.0, 2005

[13] IEC 61643-12: Low-voltage surge protective devices - Part 12: Surge protective devices connected to low-voltage power distribution systems - Selection and application principles. Ed.2.0, 2008

[14] IEC 61643-21: Low voltage surge protective devices – Part 21: Surge protective devices connected to telecommunications and signaling networks – Performance requirements and testing methods. Ed.1.1, 2009

[15] IEC 61643-22: Low voltage surge protective devices – Part 21: Surge protective devices connected to telecommunications and signaling networks – Selection and application principles. First Edition, 2004

[16] IEC 60664-1: Insulation coordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests

[17] NFPA 780: Standard for the Installation of Lightning Protection Systems, 2008 Edition, NFPA, USA

[18] DIN EN 62305-3 Beiblatt 5: Blitzschutz – Teil 3: Schutz von baulichen Anlagen und Personen – Beiblatt 5: Blitz- und Überspannungsschutz für PV-Stromversorgungssysteme

[19] IEC 61000-4-5: Electromagnetic compatibility (EMC)-Part 4-5: Testing and measurement techniques–Surge immunity test (2001-04)


ATTACHMENT V

GCI Outdoor Antenna and Indoor Equipment Requirements Global Communications Infrastructure (GCI) VSAT Antenna shall be installed with non-penetrating mount (NPM) for IS20. The NPM to be used for this application is the Baird VL-4 with a single tray/leg configuration for the ballast. Both the GCI Outdoor and Indoor equipment will be installed and commissioned by the GCI Contractor upon the required civil works are completed.

Site: IS20 Address: 0°36'36.0"S 90°22'12.0"W Latitude: -0.6050° Longitude: -90.3660° Satellite: 22W SES-4 Elevation: 13.2° Azimuth (true): 89.7° Azimuth (magn.): 85.6°

Following civil works and related infrastructure works are required for the GCI elements -

Outdoor Components The GCI satellite dish must be located in an area with an unobstructed view of the satellite and free

from any other RF and electrical interference. Trimming or clearing of trees and vegetation be made for the clear line of sight/look angle for the Satellite.

The Contractor shall build appropriately reinforced concrete base for a GCI satellite antenna. The concrete pad must be able to support the 3.14 x 3.14 m (9.8596 m2) / 10.3 x 10.3 ft (106.11 sqft) non-penetrating mount for the VSAT Antenna (See Figure 1 for specification reference.)

The Contractor shall arrange and provide not more than 32 standard concrete blocks (16 inches x 8 inches x 8 inches) with a total weight of 478 lbs / 217 kg for the Ballast1 at the GCI satellite antenna installation location. (See Figure 2 for specification reference.)

The Contractor shall construct a protection fence with a small door around the GCI VSAT Antenna if the VSAT installation location is on the ground. (This requirement is optional if the VSAT is to be installed within a gated and walled compound or VSAT antenna installation is on the rooftop.)

The Contractor shall construct and install adequate weatherproof (with water drain) cable trenches, ducts, and conduits between the GCI Indoor equipment location and Outdoor Antenna for the Inter-Facilities Link (IFL) cable.

Common earth grounding facility (earth point) shall be made available for the GCI VSAT Antenna. The civil work shall provide a good antenna earth within 10 m of the proposed antenna site. Usually, a good building earth (for example an earthed structural steel member, metallic cold water pipe or copper spike driven into the ground) is sufficient.

For the location with cold or extreme temperature environments, an anti-ice mechanism for the VSAT antenna may be required. In such cases, ruggedized outdoor power socket shall be made available close to the GCI VSAT antenna assembly. Separate power duct or conduit installation is preferred, and it shall not be shared with the IFL cable conduit.

1 Ballast materials for the VSAT antenna mount has to be calculated specifically based on the ground level/elevation,

and wind speed on case by case basis.

Indoor Components The Contractor shall make sure the adequate ventilation and air conditioning at the GCI Indoor

equipment location.

For the GCI Indoor equipment, there are no other specific requirements other than typical computing equipment requirements for the HVAC related matters, and it is desirable that GCI indoor equipment is installed in the secure telecommunication rack or enclosure.

The telecommunication rack is optional as long as the indoor equipment is placed in a secured manner with proper cooling and ventilation in the dust free environment.

Followings are the typical GCI indoor equipment specifications: o iDirect 3100 Satellite Modem (1U space in the rack); o Cisco 891F Network Router (1U space in the rack); o APC UPS and Battery Pack (from 8U, and up to 12U space in the rack);

There will be a couple of GCI equipment spares (router, modem, BUC, LNB, Feedhorn, etc.) to be stored on site, and they should be stored in an easily accessible secured location.

Cabling Path and Routing Requirements The cabling path for the IFL cable between the outdoor VSAT Antenna and indoor equipment (i.e.

Satellite Modem) shall be determined according to the GCI Site Survey document, and any required cabling trenches, ducts, conduit, and point of entry be made.

The Contractor shall construct and install adequate weatherproof (with water drain) cable trenches, ducts, and conduits between the GCI Indoor equipment location and Outdoor Antenna. The Contractor shall also provide and install waterproof conduits (with draw ropes) in the trench which will be used to bring the cables from the satellite dish to the GCI indoor unit. The conduits must be waterproof and should enter the indoor equipment room through a port in the wall. The trench should not be filled in until the Commission’s GCI contractor has installed the cables for the satellite antenna.

The minimum inside diameter of the ducting shall be 2 inches (50 mm), and the cabling routes shall be able to maintain the bend radius of up to 4 inches (100 mm).

For the location with cold or extreme temperature environments, an anti-ice mechanism for the VSAT antenna may be required. In such cases, ruggedized outdoor power socket shall be made available close to the GCI VSAT antenna assembly. Separate power duct or conduit installation is preferred, and it shall not be shared with the IFL cable conduit.

Power Requirements Regulated, stable, and clean electrical power shall be provided to the GCI equipment. Installation of

automatic voltage regulator may be required if there are any power deficiencies observed.

Standard electrical power sockets for the GCI equipment shall be installed with earth grounding in accordance with the local electrical regulations.

The power lines and electrical outlets shall sustain at least 180 W for the GCI equipment o The modem has a maximum of 120 W and router has a maximum of 60 W power

requirements. They can be operated in either 110 VAC or 220 VAC.

Grounded power lines and electrical sockets for the UPS connection shall be implemented accordingly.

o 1500 VA UPS for 110 VAC power supply source; o 1000 VA UPS for 220 VAC power supply source.

Should the anti-ice mechanism is required for the GCI VSAT antenna, the ruggedized outdoor power socket shall be installed close to the GCI VSAT antenna assembly, and must be able to sustain up to 1000 Watts2. The cable should be a #10 AWG (5.3 mm2) stranded copper wire coded in accordance with local electrical regulations, and the maximum cable length should be under 15 m (50 ft). The power for the anti-ice mechanism should be a separate power source from that of the Indoor unit.

2 The power requirement for anti-ice may vary on case by case basis depending on the type of anti-ice equipment

installed.

Figures and Specifications

Figure 1: Dimensions and product information for the VSAT antenna mount

Figure 2: Standard concrete block (16”x8”x8”) for the Ballast weight

ATTACHMENT VI

General Technical Specifications for Vehicle

№ General Technical Specification for the Station Vehicle

4-wheel drive, heavy duty, high performance vehicle for on/off-road, especially applicable

to the local climate.

I GENERAL 1 Type of vehicle Pickup truck, double cabin, 4 doors, Long Wheel Base

2 Arrangement 4 wheel drive, 4 х 4

3 Body colour Any (preferable white).

4 Seats A minimum of 5 seats

5 Payload 500 – 1200 kg

6 Safety Dual airbags

7 safety Electric windows

8 safety Central door locking

II ENGINE 1 Engine type 4/6 cylinders, injection type

2 Engine capacity 2,0 – 4,5 litres.

3 Power, Kw not less than 76 kW but not more than 200 kW

4 Type of fuel Diesel

5 Cooling system water cooled

III TRANSMISSION 1 Gearbox 5 speeds synchromesh and transfer box with high and low ratios (differential

switch – 2 speed high and low range transfer box)

IV WHEELS AND SUSPENSION 1 Tyres not less 175/R16-R17 radial or its equivalents, tubeless type

2 Spare wheel spare wheel complete set (including lifting jack) secured from theft

3 Brakes Disk brakes (front wheels) and ABS on the 4 wheels

4 Suspension Optimized for use over rough terrain

5. Ground Clearance Min. 212mm

V DEVICES (DASHBOARD) 1 Standard

instrument panel

Tachometer, speedometer (km/h); odometer (km); fuel gauge; oil pressure

gauge; water temperature gauge; head lamps indicator; direction signal lamps

indicator; hand brake warning light; emergency button; (on/off) differential

switch;

2 Steering As local standard; power assisted

VI FUEL CONSUMPTION 1 Liters/100 km: 9 – 18 litres per 100 km (excluding air-conditioner consumption)

VII ACCESSORIES 1 Air condition

system

efficient integrated air conditioning system capable of controlling the

temperature of a fully occupied vehicle

2 Protectors Vulnerable components on the underside of the vehicle (excluding engine oil

sump and front differential) should be protected with sturdy guards.

3 Tyres A full set of extra wheels with winter tyres and with show chains.

4 Canopy Hard top (lockable) canopy.

5 ESP Electronic Stability Control system

VIII OTHER REQUIREMENTS

1 Warranty at least 24 months

2 Winch (desirable but not

essential).

Integrated electric winch capable of extracting a fully loaded vehicle

from bogs, creek beds, etc.

3 Availability of

maintenance service

Authorized maintenance services in local area.

4 It is expected that vehicles to be offered should be similar to those

listed below: (please provide quotation from local manufacturer when

possible)

- Toyota (Hilux);

- Nissan (Frontier);

- Ford (Ranger);

- Mitsubishi (L200);

- GM (S10)

5

Delivery

Vehicle should be delivered locally (DDP) to Puerto Apoyo, Santa

Cruz, Galápagos, Ecuador.

annex d terms of reference site preparation, construction… · 2016. 4. 29. · site preparation,...

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