1.attachment-i- technical specifications - copie

8/18/2019 1.Attachment-I- Technical Specifications - Copie

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0 28.12.09 ISSUED FOR IMPLEMENTATIONS NB BC BC

Rev. No Date Purpose Prepared byReviewed

byApproved

by

Template No. 5-0000-0001-T1 Rev. 1 Copyrights EIL – All rights reserved

Document No.6891-0645-CP-002

Rev. No.0

Page 1 of 98

NEW FCCU PROJECT, HPCL, MUMBAI

(SMMS)

JOB SPECIFICATION

FOR

CATHODIC PROTECTION SYSTEM

FORSEAWATER LINE

AND

UNDERGROUND VESSELS

NEW FCCU PROJECT, HPCL, MUMBAI

TECHNICAL VOLUME


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NEW FCCU PROJECT, HPCL,MUMBAI

(SMMS)

TABLE OF CONTENTS

Section/ Sub-sectionNo.

Description

1.0 Scope Of Work

1.1 Scope Of Work For Cathodic Protection System (CP System)

1.2 Scope Of Work For CP System installation

1.3 Instruction To Bidders

1.4 Specific Requirements For CP System Works

2.0 Design Basis/ Philosophy For CP System

2.1 Codes And Standards

2.2 Scheme For CP System

2.3 Design Basis For CP System

2.4 Detailed Engineering Works To Be Performed By Contractor ForCP System

3.0 Specification For CP System Equipment and Materials

3.1 Specification for natural air cooled transformer/ rectifier unit

3.2 CP System Power distribution board (PDB)

3.3 Mixed metal oxide coated titanium tubular anode

3.4 Permanent reference cell

3.5 Mixed Metal Oxide Wire Anode3.6 Anode, cathode & monitoring junction boxes (AJB), (CJB), (MJB)

3.7 Cables

3.8 Calcined petroleum coke breeze

3.9 Thermit welding

3.10 Materials/ equipment for operation and maintenance

3.11 Specification For Painting Corrosion protection for junction boxes,

PDB, cable markers and junction boxes support structures

3.12 Specification For Central monitoring and control system

3.13 Specification For Soil Resistivity Test

4.0 Tentative Bill of Materials (BOQ)

5.0 Mandatory Spares For Cathodic Protection System

6.0 Vendor list for CP System

7.0 Drawing List for C P System


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1.0 SCOPE OF WORK


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CONTENTS

SECTION DESCRIPTION

1.1 SCOPE OF WORK FOR CATHODIC PROTECTION SYSTEM(CP SYSTEM)

1.2 SCOPE OF WORK FOR CP SYSTEM INSTALLATION

1.3 INSTRUCTION TO BIDDERS

1.4 SPECIFIC REQUIREMENTS FOR CP SYSTEM WORKS


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1.0 SCOPE OF WORK

1.1 The work to be performed by the contractor shall comprise of design, detailedengineering, supply, installation, testing, and commissioning of impressed Current CathodicProtection (CP) System for plant underground seawater cooling(SWS/SWR) pipeline 40”

dia.x500m long in unit and offsite areas , at HPCL MAHUL Terminal as shown in Layoutdrawing no. 6891-114-50-47-0405, Rev.0. And underground vessels within the battery limit

of NEW FCCU PROJECT, HPCL complex at MUMBAI, MAHARASHTRA. Theschedule of the under ground vessels to be protected shall be as follows:

T

hi

s

d

This document is not intended to be all- inclusive and the use of the guidelines set forth heredo not relieve the CONTRACTOR of his responsibility of providing adequate CP System,

which shall be proved performing to the entire satisfaction of the OWNER/ EIL.

The contractor also need to supply all materials, consumables in his scope of supply and

provide all construction tools, tackles, equipment and personnel necessary for the work andsubmit construction drawings and as built drawings including soft copies in latest version of

AutoCAD and operating manuals after completion of work. One set of soft copy and hardcopy of all drawing/ document to be submitted to EIL and six set of hard copy and one setof soft copy to be submitted to client for records.

The Contractor needs to keep vigilance and take all precautionary measures to prevent fire

hazards during execution of job.

1.2 Scope of work for Cathodic Protection (CP) System Installation

Item wise works envisaged under this Contract will comprise of the following:

1.2.1 Preparation and submission of Design, Detail Engineering package as per Design

basis and job specifications enclosed in this bid document. The detail engineeringpackage shall include, as a minimum, design calculations, calculation andpreparation of Bill of quantities, layout drawings of all materials/ equipment of CP

System, Connection schemes and wiring diagrams, Installation procedures, Name ofequipment suppliers, shop/ field Testing & Inspection plan for equipment, necessarytechnical information/ datasheets, fabrication / construction drawings, Testing and

commissioning procedures and formats, Quality control/ Quality assurancedocuments etc. & obtain approval from OWNER/ EIL before execution of work.

CONTRACTOR needs to obtain approval on all layout drawings of Cathodic

Sl.

No.

Item No. Description Inside

Dia

(mm)

T.L. to

T.L.

(mm)

Design.

Temp.O

C

Location

1. 114-D-3028 Closed blow downdrum

1800 5500 200 FCCU

2. 120-D-1002Amine Blow down

Drum1600 5000

65 FCCU


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Protection materials/ equipment at site from OWNER/ EIL before starting theinstallation work.

1.2.2(a) Carry out soil resistivity survey at 10 locations (locations to be decided by EIL) by

wenner-4 Pin method and presentation of result to EIL (Soil chemical analysis neednot be done).

1.2.2 (b) Carry out detailed engineering, Supply all materials, equipment and perform all

erection and installation work as per approved detail-engineering package. Provisionof service connection to T/R units shall be in CONTRACTOR's scope of work.

1.2.3 Shop testing of all major contractor supplied CP equipment (T/R, Anode, Cables,Junction Boxes etc.) and submission to EIL of Test results/ certificates for approval

before delivery of equipment.

1.2.4 Field-testing of individual components of CP System as per approved detail

engineering package. Final commissioning of installed system as per approvedprocedure and submission to EIL of results thereof.

1.2.6 Liaison with other agencies, seek and obtain all permission related and obligatory tohis part of the work.

1.2.7 Preparation and submission of 1 set of soft copy and 6 sets of hard copies to client

and one set each soft and hard copy to EIL for records for all as built CP Systempackage comprising of operation and maintenance manual for equipment, as-builtdrawings, Material specifications and Pre-commissioning/ Commissioning results.

1.2.8 After Commissioning of the CP System, if it is found that structure to electrolyte

potential achieved at some location is in the range which is below acceptable limit asper code, then a supplementary CP System need to be installed to bring the potentiallevel at such locations within acceptable limit as mentioned vide Document No.

6891-0645-CP-002, subsection 2, for "Design Basis/ Philosophy for CP System",

1.2.9 CONTRACTOR shall give performance guarantee for CP System of undergroundvessels as per design basis and job specifications and operation guarantee of thematerial and equipment supplied by him as well as guarantee against defective

workmanship for installation work carried out by him.

1.3 INSTRUCTION TO BIDDERS

1.3.1 Site Particulars

It shall be the bidder's responsibility to have a thorough understanding of the

reference documents, site conditions and specification included therein. Theintending bidders shall be deemed to have visited the site and have studied theconditions before submitting the Bids. Non-familiarity with the site conditions will

not be considered a reason either for extra claims or for not carrying out the work instrict conformity with the drawings and specifications.


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1.3.2 Every item of work and supply by CONTRACTOR shall be subject to Engineer-In-Charge scrutiny, supervision and approval. Any work carried out or supplies

effected without such approval shall stand automatically rejected and his claim forcompensation for such unauthorised work shall be null and void.

1.3.3 Bidder to note that all bought outs shall be supplied only from the list of approved

vendors given elsewhere in the document. For any item for which list of approvedvendors not furnished, Bidder shall propose, on award of Contract, vendor names &

obtain Client’s Consultant’s approval before placement of order on the ve ndor.

1.3.4 Bidder to note that the time schedule for the CP System work shall be 5 months

from the date of FOI/LOI. The work front for CP System for each location shall begiven to the CP System contractor by others as and when it is ready. Therefore CP

System contractor need to be required to mobilize and demobilize at site with man

material and equipment as per the availability of the work front.1.3.4 Information to Be Furnished By Bidder along with Technical Bid

The bidder shall prepare a separate technical proposal for this work. This proposalshall, as a minimum include the following information:

a) Two separate organisation charts to be furnished along with two different

headings as follows:

i) Complete organisation chart with Bio data to key personnel for the entire

organisation of the Bidder.

ii) The site organisation chart with Bio data of the Personnel to be deployed at sitefull time for the entire duration of this Project.

Additional manpower if asked by EIL depending upon the exigencies of the workshall be provided by the Contractor with out any extra cost to Owner.

b) Bidders are required to confirm the supply of Tentative Bill of quantities (BOQ)for all major materials as mentioned vide section 4.0 of this document, and also

required to furnish drawings, documents and all other supporting evidence toenable EIL to make an objective evaluation of their bids in all respects. However

bidder may note, after award of contract they have to carry out the detailedengineering of C.P. System as per design guidelines given in this document.

Quantities approved by Owner/ EIL after detailed engineering shall beconsidered for installation purpose.

c) List of materials/ equipment and consumables to be procured from Indianmarket along with names of suppliers/ manufacturers and brief technical details,make of the equipment.

d) List of materials/ equipment and consumables to be procured from foreign

market along with name of supplier/ manufacturer and Make, Tech.


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specification/ detail of equipment as per information required in Spec No. 6891-0645-CP-002.

e) In case the bidder takes any deviation to the terms and conditions of the tender

specifications, the bidder must list all such exceptions/ deviations in properformats. In case no exceptions/ deviations are contemplated, the bidder must fillup the proforma with the words "NIL EXCEPTIONS AND DEVIATIONS".

f) To confirm necessary hot/ cold permit shall be taken by Bidder from OWNER as

per safety procedures applicable at site before starting of hot/ cold work inside theplant area.

g) Quantified list along with Make/ Model/ technical data/ catalogues of the majorconstruction equipment, tools, tackles and testing/ commissioning instruments,

the bidder proposes to use for execution of the work. Depending on the exigency

of the work contractor may have to mobilise additional construction equipmentwithout any extra cost & time impact.

i) Bar chart giving details how Bidder plans to execute the work within the specifiedtime schedule.

1.4 SPECIFIC REQUIREMENTS FOR CP SYSTEM WORKS

1.4.1 General

Clauses given under specific requirements for CP System works shall be read in

conjunction with General conditions of contract and in case of any conflict, theprovisions of specific requirements for CP System works will override the provisionof general conditions of contract.

1.4.2 EIL/ OWNER shall have the right to inspect the following:

- Workshop & production facilities available with CONTRACTOR or its tie upagency.

- Fabrication/ testing of material/ equipment to be supplied by CONTRACTOR or

its tie up agency for CP system.

It shall be Bidder's responsibility to arrange access for EIL/ OWNER Personnel forsuch visits. All costs related with travel, boarding, lodging for EIL/ OWNERpersonnel for such visits (if any) shall be borne by EIL/ OWNER.

1.4.3 `A' class Electrical Contractor license is essentially required as per regulations laidby electrical inspector of the state for electrical jobs. The Contractor shall arrange

for the same. Any approval from electrical inspector required for the electricalinstallation shall be in Contractor's scope.


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1.4.4 Materials

1.4.4.1 Material Supplied By Owner

No material for CP System shall be supplied by owner.

1.4.4.2 Material Supplied By Contractor

The Contractor shall procure supply all materials, equipment and consumables

required for the work in his scope. Technical specifications of major items are givenin Spec. No. 6891-0645-CP-002, sub-section 3.0, of this document. Supply of allbalance materials, consumables not covered in Spec. No. 6891-0645-CP-002, sub-

section 3.0 but required for completion of work as per this specification shall beentirely Contractor's responsibility. The rates quoted for the execution of the

Contract shall be inclusive of all Contractor supplied material and equipment.

1.4.5 Warranty

Contractor need to provide design guarantee for the system as per codes andstandards & the protection criteria mentioned in the section “Design basis” of this

document. Contractor needs to replace/ repair or reinstall free of cost any material/ equipment supplied or installed by him in case it fails to operate due to defective

material or workmanship as per requirements of this specification within 12(Twelve) months from the date of issue of completion certificate and acceptance ofthe CP System by Owner. Contractor shall replace at his own cost if any item found

defective or missed before handing over the system to owner.

1.4.6 Construction Aids, Equipment, Tools and Tackles

Contractor shall be solely responsible for making available for executing the work,

all requisite construction Equipment, special Aids, tools, tackles and testingequipment and appliances, all instruments including automatic Programmable

current interrupters required for commissioning and interference testing of thesystem. Such construction equipment shall be in first class operating condition. Anydiscrepancies pointed out by Owner/ EIL shall be immediately got rectified, repaired

or the equipment replaced all together by Contractor. Owner/ EIL shall not in anyway be responsible for providing any such equipment, machinery tools and tackles

etc. The Owner/ EIL reserve the right to re-arrange such deployment depending uponthe progress and priority of work in various sections at no extra cost to Owner.

1.4.7 Transportation, Packing and Handling

Contractor shall be responsible for transportation of all equipment/ materialsrequired for CP system work and unload the same at allotted area at site.


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1.4.7.1 To protect all the material during period of dispatch, storage and erection againstcorrosion, incidental damage due to vermin, sunlight, rain, high temperature, humid

atmosphere, rough handling in transit and storage in open during monsoon includingdelays in transit. Bidder shall be responsible for any damage to equipment/ material

due to above reasons.

1.4.8 Bidder to refer in technical volume : Document No. 6891-0645-CP-002:

The “Scope of Work”, "Design Basis/ Philosophy for CP System", "Jobspecifications for CP System", “Tentative Bill of Materials (BOQ), "Mandatory

Spares for CP System", “Vendor List for CP System", “CP System drawing List”


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2.0 DESIGN BASIS/ PHILOSOPHY FOR CP SYSTEM


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CONTENTS

Section

No.

Description

2.1 Codes and Standards

2.2 Scheme for Cathodic Protection (CP) System

2.3 Design basis for CP System of underground vessels

2.4 Detailed Engineering Works To Be Performed By Contractor For

CP System of underground Vessels


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2.1 Codes and Standards

The entire work shall be performed as per the following codes/ standards.

∗ NACE : RP-0169-97, RP-0285-95

∗ BS : 7361 Part I-1991 ( Formerly CP 1021-1973)

∗ VDE : 0150, protection against corrosion due to straycurrents from DC

installations.

∗ DIN : 30676

∗ IEC/ NEC : Relevant codes

∗ Indian electricity act and rules framed there under.

∗ Fire insurance regulations.

∗ Regulations laid by Chief Electrical Inspector of State.

∗ Regulations laid by Chief Inspector of Explosives.

∗ Regulation laid by Factory Inspector of State.∗ Petroleum Act, 1976 (Govt. of India., Corrosion control in Petroleum production

TPC Publication No.5)

Wherever the requirements in this specification are in conflict with any of the above

standards, the requirements of this specification shall be binding.

2.2 Scheme for Cathodic Protection (CP) System

Impressed Current Cathodic Protection (CP) System for soil side corrosion prevention of

seawater line and underground vessels as given at scope of work, within the battery limit ofNEW FCCU PROJECT, HPCL complex at MUMBAI, MAHARASHTRA. Anodes tobe considered shall be close continuous distributed type string anode of mixed metal oxide

wire, piggyback connected with anode lead cable, factory pre-packed with coke breeze forthe U/G vessels and MMO tubular anode for seawater line. The tentative requirement of the

Bill of materials (BOQ) for each vessel and seawater line to be supplied by Contractor isfurnished in the section 4.0 of this document. Free ends of each loop of string anode shall beterminated to AJB. One No. indoor type, air cooled, Transformer-Rectifier unit (T/R Unit)

25V/ 25A rating shall installed to energise the anode strings for both the vessels through 1No. each of anode junction boxes (AJB). Each T/R Unit shall have one outgoing positive

header cable, which shall be terminated to AJB to be installed near each vessel(through in-out connection). Each T/R Unit shall have one out going negative header cable, which shallbe terminated, to a cathode junction box cum test station (CJB). CJB cum test station

(CJB) is to be installed near each vessel and seawater line for the drainage connection andpotential measurement. Two drainage cables and two measurement cables from the vesseland seawater line shall be terminated to its CJB. Power supply for the T/R Unit shall be

drawn by contractor from the Electrical substation-10. OWNER shall provide 3-Phase, 4-wire, 400V power supply for CP System at the Electrical substation, one 250A/ 63A, 415V,

TP circuit breaker/ Switch Fuse unit shall be allotted by OWNER at the Electricalsubstation-10. CONTRACTOR need to lay one 3-phase, 4-wire (300/ 50 sq. mm ) powersupply cable from this circuit breaker/ Switch Fuse unit outlet to one indoor type wal

mounted PDB near the T/R Unit location for distribution of power to the T/R Unit. Each TR


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Unit and PDB should be located at non-classified area inside the electrical S/S-10.Monitoring of CP System performance shall be done by installation of 4 No. of permanent

reference cells for each vessel and 20 No. of permanent reference cells along the seawaterline route. All the reference cells to be installed and the output current / voltage of

connected respective TRU are required to be part of the central monitoring system.The reference cell cables and the measurement cables from each vessel and the seawaterline shall be routed through the respective cathode junction box cum test station (CJB) to a

single Monitoring Junction Box (MJB), which shall be located near the T/R Units and havethe provision of measurement of vessel/pipe to soil potential. Also for monitoring of vessel

/pipe to soil potentials at the T/R unit, monitoring cables consisting of reference cell andmeasurement cables shall be laid between MJB and T/R unit for connection of tworeference cells to each T/R Unit panel. Selector shall be used at the TR Unit for

measurement of potential for each reference cell. The T/R Units, PDB, and MJB shall beinstalled at one location inside the Electrical S/S-10. All Cable laying should be done on

existing overhead cable trays/ cable trenches wherever possible. Underground Cable laying

in paved/ unpaved areas should be done as per enclosed drawing wherever overhead cabletrays/ cable trenches are not available. Connection of drainage cables and measurement

cables to the Vessel shall be done by Thermit welding.

2.2.1 Contractor shall carryout detailed engineering, procurement, installation, testing and

commissioning of the following major materials/ equipment as per the above-mentioned

basic scheme for Cathodic Protection System for the buried vessel:

a) Transformer/ Rectifier (T/R) units : T/R unit 2 No. 75V/ 75A capacity and 1 No.25V/ 25A capacity; air cooled, indoor plinth mounted type and shall be installed at

non-classified locations inside S/S-10. The enclosure of T/R units shall be IP-55 as per

relevant IEC/ NEC codes as per enclosed subsection 3.0.

The T/R units shall have programmable current interruption facility according to a

schedule defined by the user. Interruption ON / OFF cycle should be programmable inthe time ratio selectable from 0 to 999 seconds in increments of 1 second. Theinterruption device shall be solid state type without any mechanical moving parts and shallhave arrangement for bypass.

b) Anode Beds:

i) For vessel : Anodes minimum 213m length to be considered shall be close continuous

distributed type string anode of mixed metal oxide wire, piggyback connected with

anode lead cable, factory pre-packed with coke breeze. The anode strings shall be laid inthe sand cushion of the vessel backfill, in the form of several loops surrounding the

vessel. The general specifications of mixed metal oxide coated on titanium wire anodefactory pre-packed with coke breeze is enclosed in SECTION 3.0. Following guide lines

shall be considered for uniform current distribution:

- Separation distance of String anode from vessel to be protected shall be 0.30m


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Free ends of each anode string loop should be connected to AJB. Thus 2 No. of anodelead cables from each loop shall be terminated to AJB

- Vertical separation distance between each consecutive anode string shall be 0.30m

or as decided during the detailed engineering stage.

The contractor need to execute the work as per the detailed engineering package to beprepared by them and approved by EIL/ OWNER during execution stage. Datacollection for soil/ sand resistivity to be done as per scope of work & enclosed

Specification given in SECTION 3.0 .-

ii) A trained cable jointer need perform the anode lead cable to anode string joints, at

factoryor at field.

iii) Sand resistivity need to be considered for the Vessel CP System design as 200 ohm- m.

iv) The vessel shall have suitable paint for the soil side corrosion protection.

v) The Minimum quantity of CP System materials and TR Unit ratings as mentioned inSection 4.0 “Tentative Bill of Materials (BOQ)” of this document need to be offered by

all bidders. During detailed engineering stage, if bidders offer more than the minimumquantity of materials or rating of TR Units mentioned, that should be acceptable butlower than the minimum quantity of materials or rating of TR Units mentioned here

should not be acceptable.

vi) In case desired by EIL /OWNER as an (optional) item, CP System contractor need toSupply and backfill fine sand within the RCC pits for backfilling of the UG Vesselsand CP System materials to be installed inside the RCC pit including making of 75mm

PCC Cover on the pit. The sand filling shall be done as follows:

• The internal dimension of the pit for sand filling purpose need to be considered5000mm(h)x8000mm(l)x7068(w).

• Sand shall be backfilled in layers of maximum 250mm loose thickness and compacted

to 80% relative density with suitable vibratory compactor.

• Sand type conforming to fine aggregate, IS Sieve Designation 1.18mm, Grading zone

I/II/III/IV, as per IS: 383-1970, shall be considered for backfilling the RCC PITsurrounding the vessel.

In case the sand filling inside the RCC pit and making of PCC cover over the pit is done byother agency, CP Contractor need to coordinate the CP System activity with the other agency.

ii) For seawater line:

CONTRACTOR shall mobilize at site with engineers, supervisors, techniciansskilled/unskilled labour and materials/equipment required for commencing construction

work for distributed anode bed for seawater line as follows:


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Site Preparation

CONTRACTOR shall be solely responsible for thorough investigation as to all localconditions affecting the work, including but not limited to transportation and access to the

job site, including the availability and condition of roads, disposal, handling and storage ofmaterials; availability and quality of labour, water and electric power, climatic conditions,ground water level & soil strata equipment machinery and material required by

CONTRACTOR, prior to and during performance of the work.

For commencing construction work, the CONTRACTOR shall survey and mark at site theexact location of anode ground beds as per advise of EIL(SMMS) engineers to be present atsite. All PDB,TR Unit, MJB, RTU, junction boxes, cable are to be installed as per the

construction drawings to be prepared by Contractor and approved by EIL/OWNER prior tocommencing any installation work at each site. The CONTRACTOR shall also locate with

the help of a pipe locator all existing underground piping as per layout drawings in this

project before starting drilling/excavation work.

DISTRIBUTED ANODE BED: VERTICAL

Distributed vertical anode bed system of anode bed size 6" dia x 6m deep shall be installed

at 15 to 20m interval along the seawater line route. Necessary work for bore holes forvertical anode beds, anode installation, backfilling with coke breeze and making of RCC pit

for anode beds need to be done by CONTRACTOR. The drilling of bore hole and casing ofthe bore hole for vertical distributed anode beds shall include the following:

- MS casing pipe (bottom closed) to be considered for 6" dia for 6m deep distributedanode bed.

- Top 2m of the casing pipe of 6m deep anode bed shall be coated with coaltar tape(DENSOLEN-System AS 40 Plus – C50, 4-Layer wrapping of total thickness 3.2mm)

or coal tar enamel or shrouded with 5mm W.T. PVC pipe of matching ID.

- One MS cap or PVC cap to be provided as top cover of the casing to prevent entry ofany foreign object inside the bore hole until the permanent anodes are installed insidethe casing.

Anode Installation:

MMO tubular anode complete with anode Lead Cable, non metallic centralizer and dead

weight shall be lowered centrally in each bore hole. To ensure that anodes are locatedcentrally, each anode shall be fitted with a non metallic centralizer.

Anodes shall be lowered in such fashion that bottom of anode is 150mm above the bottomof bore hole.

Annular space between casing pipe and anodes as well as between casing pipe & bore holeshall be filled by pumping calcined Petroleum coke breeze in slurry form. Procedure for


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backfilling of coke breeze shall be got approved by CONTRACTOR from EIL beforecommencing the work

One MS Plate should be used as RCC pit cover. The anode bed No. should be engravedand stencilled using paint on RCC pit cover. All 10mm2 lead cables shall be terminated

inside the respective Anode lead junction box.

The contractor needs to execute the work as per design to be approved by EIL

during the detailed engineering stage.

c) Junction Boxes: Junction Boxes (AJB & CJB) for CP System shall be as per inenclosed specification for junction boxes, vide subsection 3.0. The enclosure of AJB

& CJB shall be classified type as per Area classification and relevant IEC/ NEC codesgiven in enclosed spec. While deciding no. of Anode leads for each AJB, at least two

nos. of cable entries and cable terminals should be kept spare at each AJB for

connection of Anodes as per supplementary design, if required. In case supplementarydesign is not required in certain areas, the spare cable entries should be closed with a

threaded plug. CJB cum test station (CJB) shall be located at Rim of the Vessel andnear seawater line for the drainage connection and potential measurement. Twodrainage cables and two measurement cables from the Vessel and seawater line shall

be terminated to each CJB.

d) Cables: Cables for CP System shall be as per in enclosed specification for cables, videsubsection 3.0. All cable glands shall be of double compression weatherproof brass,nickel/ cadmium plated type, lugs shall be long barrel heavy duty tinned copper type.

All hardware used shall be of stainless or brass material.

e) Power Distribution Board (PDB):

The Power distribution board (PDB) shall be plinth mounted indoor type and shall be

installed at non-classified locations near the T/R Unit. The enclosure of shall be IP-55as per relevant IEC/NEC codes.

The Power distribution board (PDB) shall be composed of one no.3 phase, 4-wire250A/ 63A, incoming MCCB and 12/3 no. 1 phase, 63A outgoing MCB for input

power supply to TR Unit as well as 6No.6A outgoing MCB for central monitoringsystem power supply. The incoming switch shall be 3-pole and outgoing switches shall

be 2-pole. The MCCB and MCB shall be suitable for motor load application and shallbe of HAGER, SIEMENS, L&T, MERLIN GERIN, MDS, INDO ASIAN,

SCHNEIDER ELECTRIC, ABB, OR AEG make. 4 Nos. of 25 x 5mm tinned copperbus bar shall be used which should be taped by PVC tape of red, yellow and bluecolours for identification of the three phases and black colour for neutral. Wiring inside

PDB shall be done using 50mm2, 1-core, copper conductor, PVC insulated,

unarmoured cable between TPN switch neutral and neutral bus whereas rest of thewiring shall be done by 25mm

2, 1-core, copper conductor, PVC insulated unarmored

cable. All single core cables shall be used red, yellow and blue coloured for phaseconnections and black coloured for neutral connection. All cables terminations shall be

through Tinned copper cable lugs of matching cable size. All cable entries to the PDB


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situations the straight through joint kit of any standard manufacturer like Raychem orequivalent make as per OWNER/ EIL approval may be considered for jointing cables.

For installation of permanent reference cell for seawater line at each location one 4"HDPE/PVC pipe backfilled with Gypsum, Bentonite, Sodium Sulphate special backfill

material need to be installed vertically upto 2m depth by suitable drilling method as perspecification& drawing & direction of Engineer-in-Charge.

j) Carrier pipe protection inside casing pipe at road crossing:

Diamond shape zinc ribbon anode of dimension 12.7mmx14.28mm (Platine Bros,USA / Yuxi Chaina make) shall be considered for carrier pipe protection inside casingpipe at one 20m long road crossing for 40” dia. carrier pipe. Length of Zinc ribbon

anode at every location shall be 1100mm. Minimum number of Zinc ribbon anodelocations shall be 12 No. Casing insulator & heat shrinkable end seal shall be RACI

INDIA make. Minimum number of Casing insulator locations shall be 12 No. Height

of the casing insulator shall be decided based on casing pipe ID.

k) FRP Cable tray

For laying of CP System cable along the seawater pipeline route one ultraviolet/fireresistant FRP ladder type, ventilated and solid bottom cable tray manufactured andtested as per NEMA FG-1-1984 / ASTM E-84 / ASTM D-635 /IS-6746 standards and

matching with the specifications of the existing FRP trays in the plant need to besupplied and installed on existing pipe rack by CP Contractor. The tray shall be 300mm

width, 6mm thick, and 500m long supported at 3m interval. All accessories such asbends, tees, crosses, reducers, splicer, clamps and necessary hardware need to besupplied as required.

2.3 Design basis for CP System of Vessels & seawater line:

a) No Insulating joints shall be installed to isolate any incidental structures from CP

System within Battery limit. Hence the structures intended to be cathodically protectedshall be in electrical continuity with many foreign structures within the plant complex

such as RCC pavements, RCC foundations, earthing grids, other U/G structures, whichare not intended to be protected. The CP current requirement therefore shall be

governed by following factors:

- Surface area and coating quality of structures to be protected.

- Surface area and surface condition of nearby foreign structures.- Relative position of anode between foreign structure and structure intended to

be protected.

To take care of such situation CP System shall be designed & installed in two stages

by providing one preliminary design and another supplementary design as follows:


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1. Preliminary design: A preliminary design shall be made based on the scheme

mentioned in section 2.2 above. The quantities required for T/R units, PowerDistribution Boards, anode beds of various configurations, Junction boxes (AJB, CJB,

MJB, etc.), Cables of various sizes, Thermit weld connections, and any other materialsas required shall be calculated by CONTRACTOR. The locations of T/R units,Distribution Boards, anode beds of various configurations, Junction boxes (AJB, CJB,

MJB, etc.), Cables of various sizes, Thermit weld connections, shall be marked byCONTRACTOR in appropriate layout drawings and shall be submitted along with

Detail engineering package to OWNER/ EIL for approval. The T/R Units, PDB, MJBand RTU shall be installed at one location in non-classified area near the ElectricalS/S-10. The power supply for the T/R Unit/ PDB shall be drawn from the identified

cubical of the electrical substation. The locations for installation of all CP systemmaterials/ equipment shall be verified at site by OWNER/ EIL to check the practical

feasibility of installation as well as its suitability for optimum/ effective performance

as envisaged in the design. CONTRACTOR shall start installation work of CP Systemonly after site verification and approval of locations by OWNER/ EIL at site. Detailed

Engineering works to be performed by CONTRACTOR are mentioned in Section 4.0.After completion of installation work, CONTRACTOR shall carry out testing/ commissioning activities in presence of OWNER/ EIL.

2. Supplementary design: After energizing CP System as per preliminary design, the

unprotected/ under protected and over protected areas shall be identified and asupplementary design is to be made to bring all structures intended to be protectedwithin acceptable potential limits. For identification of under protected/ over-

protected areas, at first natural Str. to soil potential is to be taken at all test points inpresence of OWNER/ EIL. Then the system as per preliminary design shall be

energised at different current levels. For each current level, protection potential andprotection span of cathode structure nearest to as well as remotest to each anode bedshall be observed until predetermined current limits of Anodes or T/R units are

reached or desired protection potential levels are achieved. These observations shallbe recorded in a tabular form or graphically plotted and to be submitted to OWNER/

EIL for review. OWNER/ EIL after review/ interpretation of the instantcommissioning results or within 6 months of the polarization period of the CP System,shall decide whether any additional anode bed or additional T/R unit is required to be

installed or whether there is requirement for disconnection of some anodes/ anode bedsor any other remedial measures and the contractor shall update the CP System

accordingly at no additional cost and within a specified time acceptable to EIL/ OWNER. Incase it is decided to install additional anodes then 6A capacity MMO

tubular anodes vide subsection 3.0 need to be installed at the suitable locations asdecided by EIL.

3. The following criteria shall be followed to determine the protection levels:

- Maximum allowable vessel to soil potential with respect to Cu/ CuSO4 ref. Cell : -

2.50V(ON) or –1.10V(Instant OFF) for impressed current system


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- Minimum allowable vessel to soil potential with respect to Cu/ CuSO4 ref. Cell :--0.850 V (ON) or -100mV polarization shift (Off) or -300mV (ON) potential shift

from initial native potential. Discretion to use any of the criteria shall solely restwith Owner/ Owner's Representative.

- Interference Criteria : +100mV positive shift

b) Design life of Anode = 25 years (minimum) for impressed current CP System.

c) Test station/ test points as mentioned in the BOQ are to be considered for monitoringexternal potential of Vessels. Separate classified type CJB cum test station need to beinstalled at the rim wall of Vessel for potential monitoring, to ensure adequate

potential level of Vessels intended to be protected.

d) While deciding number of modular type 25V/ 25A and 75V/ 75A capacity T/R units,

considerations must be given to see no T/R unit is loaded more than 75% of its ratedoutput voltage & current capacity through out design life while feeding load to a single

or group of anode beds.

e) While making preliminary design contractor should make the entire endeavor to ensure

the adequacy of the design so that the requirement of supplementary design is bareminimum.

f) For continuous string/ wire anode the anode current capacity shall be considered30mA/m.

g) Identification and mitigation of interference between structures to be protected as well

as between the structures to be protected and foreign structures need to be carried outby contractor as per the requirements of the codes mentioned in this document.

h) Earthing of all T/R Units, PDB, and JUNCTION BOXES need to be done byconnecting the same with plant earthing grids, wherever plant earthing grids are not

available nearby, a separate earth pit approved by OWNER / EIL may be consideredby contractor.

i) To avoid cable damage in the long run, all cables are to be laid at the cable trayswherever possible; under ground cable laying should be considered only when no

cable trays are available nearby. All CP System cables need to be laid at power cabletrays, all multi core-monitoring cables may be laid in either electrical or

instrumentation cable trays which ever is available.

j) For road crossing of CP System cables, suitable RCC duct or PVC PIPE duct

embedded in concrete at proper depth need to be prepared by Contractor. Contractorshould get the construction drawing approved by OWNER/ EIL before execution ofthe work.

k) The type of coating and operating temperature of each Vessel should be taken into

consideration for all detail-engineering calculations.


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l) Wherever specific guidelines are not furnished for cathode structure current density or

separation distance of anode from cathode structure and spacing between consecutiveanodes, a current density for coated cathode structure and RCC incidental structure

shall be considered 5.0 mA/m2 and the same for bare cathode/ incidental structure shallbe considered 25mA/m2.

m) If operating temperatures of Vessel exceed 25 deg.C, protective current density

shall be corrected @ 0.5mA/m2 /deg.C.

n) Classified type local AJB/ CJB need to be provided near the rim of each Vessel andseawater line, for termination anode/ cathode/ reference cell/ measurement cable

connections.

2.4 Detailed Engineering Works To Be Performed By Contractor for CP System of

underground Vessels and seawater line

Following detailed engineering works are to be performed by contractor based on schemegiven vide item no.2.2 and design basis given vide item no. 2.3 of this document for CP

System of underground Vessels and seawater line:

- List of materials/ equipments to be procured from Indian market/ foreign market.

- Item wise list of vendors with their reference lists for supply of materials/ equipment.

- Calculation and Preparation of Bill of Quantities for all CP system materials and

equipment required.

Bill of quantity along with detailed calculations and preparation of specifications,

installation work procedures & fabrication/ construction drawings for following items:

- CP System power distribution board (PDB): Total quantity and connection schemeshowing group of T/R units to be connected with each CP System PDB andconnection details between owner's switch board and each CP System PDB.

- T/R unit: Total quantity, detailed circuit diagrams and their installation drawings.

- AJB/ CJB/ MJB/RTU: Total quantity and connection Scheme showing how group of

anodes, anode beds and vessels are to be connected with each AJB/ CJB/ MJB/RTU.Also fabrication drawing & schematic drawing for internal terminal arrangements andinstallation drawings for a typical AJB/ CJB/ MJB/RTU.

- Anodes: Total nos. of Anode strings and anode string to anode lead cable joint detailsfor entire CP System and their layout arrangement drawings showing no. of anode

strings in each bullet. Construction drawings and work procedures for anode to cable jointing and also for installation of anode strings.


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Design calculations showing:

- Cables: Total quantity of cables and their layout drawing for each CP Station as wellas for entire CP System for +ve header cables, -ve header cables, anode lead cables,

earthing cables, drainage cables, power supply cables and multi-core monitoringcables.

- Cable to vessel joint: Total quantity of joints and details of a typical joint.

- T/R unit wise CP System layout drawing showing how each T/R unit is connectedwith group of anode strings/ vessels through AJB/ CJB/ MJB.

- Test points: All reference cells and anode strings should be marked in a single layoutdrawing.

- Overall CP System layout drawing including all test points, anodes, anode beds, AJB,CJB, MJB/RTU, cable routes on a plot plan. All CP System materials/ equipment

shall be marked properly for easy identification on all appropriate drawings as well ason site.

- Preparation of testing & commissioning procedure for CP System.

- Preparation of construction drawings with soft copies before starting of installation/ procurement work, Preparation of Soft & hard copies of as built drawings aftercompletion of CP System work shall also be furnished.

- Quantified list of the major construction equipment, tools, tackles etc. including

Diesel engine pump set for dewatering at cable/ pipe trench the BIDDER proposes touse for execution of the work.

- Details & list of vehicles proposed to be used by the CONTRACTOR during theentire construction & commissioning period for transportation of material,

equipments, as well as movement of personnel within the plant area.

- Bar chart giving details how BIDDER plans to execute the work within the specified

time schedule.

- Quality Assurance Plans/ Procedure

The CONTRACTOR shall establish document and maintain an effective Quality Assurancesystem as outlined in recognized codes etc. and Quality Assurance Plans included inSpecifications etc. to ensure that the work is performed in a planned, systematic manner to

the best quality standards and properly documented to provide confidence that materialssupplied and/ or work executed and services performed by him conform to the applicablespecifications and all the requirements of contract document and work executed by him

shall perform satisfactorily over the entire period of its life.


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The Quality Assurance Systems Plans/ Procedures of the CONTRACTOR shall generallycover the following aspects/ details, which shall be furnished by BIDDER along with, his

detail-engineering package.

i) A Quality Assurance Organogram with curriculum vitae of key personnelresponsible for the Quality Assurance at site.

ii) Complete details pertaining to the responsibility authority and accountability of theQuality Assurance Organization of the CONTRACTOR at site.

iii) Equipments, material, Erection, Installation, Testing and commissioning controlplans for quality testing/ inspection etc.

iv) Quality Control of processes such as Thermit welding, anode to cable jointing etc.

v) Control Procedures/ Plans for calibration and safe up-keep of instruments, gaugesand similar testing equipments etc.

vi) Quality audit & Maintenance/ records/ procedures etc.

vii) Other relevant details.

Quality Assurance System Plans/ Procedures of the CONTRACTOR shall be furnished inthe form of a QA manual. BIDDER shall be required to provide explanation pertaining tothe details furnished by him in accordance with provisions contained in this clause and any

further details, as sought for by OWNER/ EIL. In addition, all the Quality AssurancePrograms/ Plans as per specifications enclosed with the Contract shall be fully complied

with by the Contractor.

- Precautionary measures to be taken to prevent fire hazard during Thermit welding

and Pin Brazing of vessel for the purpose of cable to vessel joint as well as duringinstallation, operation & maintenance of CP System.

- All other information as required in individual job specifications shall be furnishedby CONTRACTOR in his detail-engineering package.


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3.0 SPECIFICATION

FOR

CP SYSTEM EQUIPMENT

AND

MATERIALS


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CONTENTS

SECTION DESCRIPTION

3.1 SPECIFICATION FOR NATURAL AIR COOLEDTRANSFORMER/ RECTIFIER UNIT

3.2 CP SYSTEM DISTRIBUTION BOARD

3.3 MIXED METAL OXIDE COATED TITANIUM TUBULAR

ANODE

3.4 PERMANENT REFERENCE CELL

3.5 MIXED METAL OXIDE WIRE ANODE

3.6 ANODE, CATHODE & MONITORING JUNCTION BOXES

3.7 CABLES

3.8 CALCINED PETROLEUM COKE BREEZE

3.9 THERMIT WELDING

3.10 MATERIALS/ EQUIPMENT FOR OPERATION AND

MAINTENANCE

3.11 SPECIFICATION FOR PAINTING CORROSION PROTECTION

FOR JUNCTION BOXES, PDB, CABLE MARKERS ANDJUNCTION BOXES SUPPORT STRUCTURES

3.12 SPECIFICATION FOR CENTRAL MONITORING ANDCONTROL SYSTEM

3.13 SPECIFICATION FOR SOIL RESISTIVITY TEST


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3.1 SPECIFICATION

FORNATURAL OIL COOLED TRANSFORMER/ RECTIFIER UNIT


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7) IS:3700 (Part I)-1972 – General (first revision)& (Reaffirmed IS:4400 (Part I)-1967,1988)

8) IS:3700 (Part II)-1972 - Low Power signal diodes (first & IS:4400 (Part II)-1967

revision) (Reaffirmed 1988)

9) IS:3700 (Part III)-1973 - Rectifier Diodes (First revision) & IS:4400 (Part III)-1968

(Reaffirmed 1988)

10) IS:3700 (Part IV)-1968 - Low power small signal transistors& IS:4400 (Part IV) – 1981(Reaffirmed 1988)11) IS:3700 (Part V)-1968 - Power transistors (Reaffirmed1988)

12) IS:3700 (Part VI)-1968 – Switching transistors (Reaffirmed 1988)

13) IS:3700 (Part VII)-1970 - Reverse blocking triode thyristors & IS:4400 (Part VII)-1970(Reaffirmed 1988)

14) IS:3700 (Part VIII)-1970 - Voltage regulator & voltage reference diodes (Reaffirmed1988)& IS:4400 (Part VIII)-1970

15) IS:3700 (Part II)-1984 - Light emitting diodes

16) IS:8828-1978 - Miniature air-break circuit-breakers for AC circuits for voltages notexceeding 1000 volts(with Amendment No.1, Rs.1.50, and Amendment No.2)

17) IS:9224 - Low voltage fuses.

18) IS:9224 (Part I)-1979 - General requirements

19) IS:9224 (Part II)-1979 - Supplementary requirements for fuses with high breakingcapacity for Industrial application(with Amendment No.1)Superseding IS:2208)

20) IS:9224 (Part IV)-1980 - Supplementary requirements for fuse-links for the protectionof Semi conductor devices

21) IS:4064 - Air-break switches, air-break dis connectors, air break switch-dis connectors

and fuse-combination units for voltages not exceeding 1000V AC or 1200 V DC.

22) IS:4064 (Part I)-1978 - General requirements (first revision) (with Amendment No.1)(Superseding IS:2607and IS:4047)

23) IS:3070 - Surge arrestors for alternating current systems.

24) IS:3070 (Part I)-1985 - Non-linear resistor type surge arrestors (Second revision)


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25) IS:3070 (Part II)-1966 - Expulsion type lightening arrestors (with Amendment No.1(Reaffirmed 1977)

26) IS:11548 - Capacitor for surge protection, above 650V

27) IS:694-1977 - PVC insulated cables for working voltages up to and including 1100volts(second revision) with Amendments No.1 to 3) (Amendment No.1, Rs.1.50)

28) IS:3961 - Recommended current ratings for cables.

29) IS:3961 (Part II)-1967 - PVC insulated and PVC-Sheathed heavy duty cables (withAmendment No.1)

30) IS:3961 (Part IV)-1968 - Polyethylene insulated cables.

31) IS:3961 (Part V)-1968 - PVC-insulated light duty cables.

32) IS:4800 - Enameled round winding wires.

33) IS: 4800 (Part I)-1968 - Conductor data (with Amendments No.1 and 2) (Reaffirmed

1978)

34) IS: 4800 (Part-II)-1968- Maximum overall diameters (Reaffirmed 1978) (withamendment No.1)

35) IS: 4800 (Part V)-1968 - Wires for elevated temperatures (with Amendments No.1 and6) (Reaffirmed 1978)

36) IS: 4800 (Part VII)-1970 - Wires with good dielectric properties under humidconditions(with Amendments No.1 to 3) (Reaffirmed 1978)

37) IS:4800 (Part 12)-1986 - Self bonding wires, heat or solvent bonding enameled round

copper wire with temperature index 155.

38) IS:1122-1985 - Dial, scales and indexes for indicating analogue measuring instruments.

39) IS: 1248 (Part I) -1983 - Direct acting indicating analogue electrical measuring

instruments and their accessories: Part-I General requirements (Second revision)

40) IS: 1248 (Part II) -1983 - Direct acting indicating analogue electrical measuringinstruments and their accessories:Part II Ammeters and Voltmeters (Second revision)

41) IS: 6236-1971- Direct recording electrical measuring instrument (Reaffirmed 1987)

42) IS: 3107-1974 - Portable multipurpose direct (Reaffirmed 1987) - acting electrical

indicating instruments (first revision) (with Amendments No.1 & 2)


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43) IS: 2419-1979 - Dimensions for Panel mounted indicating & recording electrical

instruments (first revision) (with Amendment No.1.)

44) IS: 8573-1977 - Digital electronic DC voltmeters and DC electronic analogue-to-digitalconvertors (with Amendment No.1) (Reaffirmed1991)

Wherever the requirements in this specification are in conflict with any of the abovestandards, the requirements under this specification shall be binding.

3.1.2 TRANSFORMER

The main transformer will be the isolation type having separate primary and secondarywindings. An electrostatic shield, composed of heavy copper foil, shall be placed between

the two windings and grounded to the rectifier cabinet, for this purpose a visible lead should

be brought out from the copper foil which shall be connected to any of the mounting stud ofthe transformer core. Transformer winding wire insulation, winding interlayer insulation,

core to winding insulation shall be class F type. The transformer core and winding will bedipped in thermosetting varnish and baked. Transformer varnish will meet the standards for155 degree C operation. The transformer winding shall withstand 2,000 volt (RMS at 50

hertz) applied for one minute between the windings and between each winding and thetransformer core. Maximum temperature of transformer winding will not exceed 90 deg C

and air temperature inside the upper cabinet will not exceed 65degC at full load current atambient temperature of up to 45 deg C. Transformer full load efficiency will not be lessthan 95%.The auto transformer shall be similar to main transformer except it will have

single winding and tapping for manual mode of control.

3.1.3 RECTIFYING ELEMENTS

The power rectification shall be done by Silicon diodes mounted on heat sinks of sufficient

size to prevent the diode case temperature from exceeding 100oC at ambient temperature asper data sheet. The peak inverse voltage rating and current ratings of the diodes shall be as

per data sheet. The diodes shall be connected in Bridge circuitry for full wave rectification.Each diode in the bridge circuit shall be protected by a HRC fuse.

3.1.4 AC INPUT

The transformer rectifier units shall be designed to operate on 240 volts (+10%) AC singlephase, 50 Hz power supply. In rush current limiting reactor of suitable rating to be provided

at input line of the main transformer to avoid possibility of abnormal tripping ofMCB whileclosing circuit using MCB.

3.1.5 DC OUTPUT


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The transformer rectifier shall be designed to operate continuously at 110% rated outputcurrent and 110% rated output voltage at input supply voltage 240v (+10%) without

exceeding specified hot spot temperature limit and without damaging any components.

3.1.6 DC OUTPUT ADJUSTMENTS

The DC output control shall be available in any of the following modes, with the help of a

selector switch.

3.1.6.1 MANUAL MODE

Output voltage at 23 equal steps up to 110% rated voltage shall be available by means of

coarse and fine tap changing switches for rated input supply voltage and 110% rated outputcurrent. Tapping for output voltage control shall be taken from a separate auto transformer.

The controlled output voltage of the auto transformer shall be fed to main transformer input.

The output of the main transformer shall be rectified for DC load supply.

3.1.6.2 AUTO MODE:

Unit shall have CONSTANT OUTPUT CURRENT/ VOLTAGE CONTROL (AVCC

MODE) in AUTO MODE as per Data Sheet.

i) CONSTANT CURRENT AND VOLTAGE CONTROL (AVCC MODE)

Constant current control feature shall be achieved by automatically adjusting T/R unit

output voltage between 0 to 110% rated voltage through close loop control using T/R unitoutput current as feed back taken from the shunt inside the T/R unit so that T/R unit output

current of any value between 0 to 110% rated current does not vary more than +1.0A of setvalue when there is a change input supply voltage of +10% or change in load resistance overa specified range decided by the ratio of output voltage & current rating of the T/R unit.

ii) CONSTANT PIPE TO SOIL POTENTIAL CONTROL (NOT APPLICABLE

FOR THIS PROJECT)

Constant Pipe to soil potential (PSP) control feature shall be achieved by automatically

adjusting T/R unit output voltage between 0 to 110% rated voltage through close loopcontrol using PSP as feed back taken from external reference cell, to cause change in output

current of T/R unit so that PSP as measured by external reference cell always remainsconstant and does not vary more than +0.04% of the set potential. For feed back PSP

reference, 2 nos. Cu/ CuSO4 ref. cells to be used one operating and other standby to beselected manually with the help of a selector switch.

Continuously adjustable potentiometer to be used for setting T/R unit output current/ PSP.

Silicon controlled Rectifiers (SCR's) shall be used in the Primary Circuit of mainTransformer for close loop control of the output voltage in auto mode. The SCR's of the

transformer rectifiers will be controlled by commands from electronic circuit cards. These


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cards shall be the plug-in type Printed Circuit Board (PCB) mounted on the front panel ofthe rectifier for easy field replacement.

The printed circuit board contact pads will be chromium plated to provide easy conductionand to eliminate contact corrosion. Complete printed circuit boards will be sealed with acircuit card sealant to prevent atmospheric corrosion and fungus contamination. Circuit

elements in the control cards shall be derated properly and proper heat dissipationarrangements shall be made in the PCB so that they function properly for full load operation

of T/R unit at ambient temperature as per data sheet.

3.1.7 DC OUTPUT RIPPLE

The filter circuit shall be designed in such a manner that ripple factor does not exceed 5% at

rated load both in Auto and manual mode.

3.1.8 INPUT OVERLOAD PROTECTION

Protection from overloads on the input will be provided by Miniature circuit breakers ofsuitable rating on the input side. The trip point will be unaffected by ambient temperature.

The trip handles of individual poles of circuit breaker will be mechanically linked so that alllines are opened when an overload occurs. In addition to above MCB, HRC fuse of suitable

rating should be connected before MCB so that AC input current is limited to max. 10%excess rated input current as per data sheet.

3.1.9 OUTPUT OVERLOAD PROTECTION

Protection from overload on the output in auto mode for T/R unit having either constantcurrent control or constant pipe to soil potential control will be provided by another closeloop SCR control circuitry giving automatic constant current control same as mentioned

vide 3.1.6.2 (i) except that it will act as back up control to main auto mode control. SeparatePCB shall be used for main auto mode control and the backup control. The current limit for

backup control is to be set by two limit switches marked "coarse" and "fine". The limits ofthe two switches shall be algebraically additive and shall give equal steps of 3A each up to110% rated current. One scale calibrated in Ampere shall be provided with each limit

switches so that current limit can be set by operator at any desired value in 3A step. In anycircumstances even in case of short circuit the T/R unit output current should not exceed the

current limit set by the backup control.

In addition to above electronic current limiting feature HRC fuse of suitable ratings to beused at positive and negative terminals as well as one double pole MCB of suitable rating tobe connected after HRC fuse at the out put to disconnect T/R unit quickly in case of over

loads in the output circuit or for ease of isolating T/R Unit from the circuit when it is desired

to keep the T/R Unit in standby mode.

3.1.10 VOLTAGE SURGE PROTECTION


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Each silicon controlled rectifier (SCR) and Diodes shall be protected from voltage surges by

means of R-C circuitry. This R-C circuitry will be rated as recommended by themanufacturer of the SCR/ Diodes so that they will conduct heavily before the peak inverse

voltage ratings of the SCR/ Diodes are reached. In addition, lighting arrestors and zener

Barrier type or MOV type surge Diverters shall be provided in the AC input and DC output

circuit of the Transformer rectifier as per data sheet.

3.1.11 COOLING

The transformer/ rectifier will be air cooled completely enclosed IP55 construction. The

temperature of the transformer winding shall not be more than 90 OC and maximum airtemperature of the upper cabinet should not be more than 65 OC for ambient temperature of

up to 45O

C.

3.1.12 INPUT AND OUTPUT TERMINALS

DC terminals made of tinned plated copper shall be located convenient to the cableentrance. The terminals shall be suitable for cable sizes as per data sheet. Three negative

and three positive output terminals shall be provided.

AC terminals shall be insulated to withstand 2000 volts 50Hz to the enclosure, shall beshielded to prevent accidental contact and shall be sized to take cable sizes as per data sheet.

3.1.13 METERS

The transformer rectifier units shall be equipped with separate continuous reading voltmeterand ammeter for the D.C output and the A.C. input voltage, current and Structure toelectrolyte Potential measurement meter with selector switch for selection of different

Structure to electrolyte Potential measurement meter. All meters shall be electronic digitaltype with LED display arrangement and should be able to indicate the current and voltage

ranges as per data sheet up to a resolution of one decimal place for DC Ammeter &Voltmeter and 3 decimal places for Potential measurement meter. Digit size should be12.5mm (minimum). All meters shall be rectangular in shape and accurate to within 2% at

full load at ambient temp. as per data sheet. They shall be temperature compensated to varyno more than 1% per 10% temperature changes.

All AC & DC voltmeters shall be provided with separate fuse and toggle switch where as all

Ammeters shall be provided with only toggle switch.

3.1.14 ANNUNCIATION

Each transformer rectifier shall be supplied with a continuous signal light which will go outat loss of A.C input. In addition to this each T/R unit should give annunciation for Auto and

manual mode of operation by continuous signal light. T/R unit should also indicate the


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failure of each fuse in bridge rectifier and two DC output fuses by an independent LED foreach.

3.1.15 ENCLOSURES

"The enclosure of T/R unit shall be plinth mounted type having two compartments. Lowercompartment shall contain main transformer, Auto-transformer, DC choke. The upper

compartment shall contain the SCRs, Diodes, indicating meters, Protective devices,Electronic control circuits/ control cords etc. and shall be provided with a Plexiglas viewing

window. Both the compartments shall be completely enclosed type having IP55construction.

The enclosure shall have a frame work made of minimum 50mmx50mmx3mm angle iron,the upper cabinet body shall be made of minimum 12SWG (2.67mm) W.T. sheet steel,

lower cabinet shall be 10 SWG(3.25mm) W.T sheet steel and bottom plate of lower and

upper compartment shall be 8mm(min.) thick steel plate. Size of enclosure shall beminimum 1700(H) x 700(W) x 550mm (D) or higher size than this. Necessary fins for the

cooling purpose shall be provided at lower compartment. A detachable sun/ rain shade to beprovided of suitable size.

The transformer rectifier shall be provided with the following accessories.

• Steel channel under the base for plinth mounting.• Lifting lugs of size suitable for lifting complete transformer rectifier unit when full

of oil to be welded at the 8mm thick bottom plate of upper cabinet.

• Locatable control cabinet with viewing window to IP55 as a minimum.

Accessibility shall be provided by hinged and removable front and back shutters. APlexiglas viewing window shall be provided at the front shutter to allow the meters to beread without opening the front shutter. One drawing pocket shall be made at inner side of

the front shutter. One holder for 60 watt filament lamp connection shall be provided at astrategic point inside the cabinet to facilitate proper illumination during operation and

maintenance. The enclosure shall be supplied with an engraved warning level with thewords "DANGER". Two junction boxes shall be provided at both sides of the uppercompartment, one of them A.C. cable entries and other for D.C cable entries. Gland plate

should be provided against each junction box for fixing single compression cable glands forA.C DC control/ monitoring cables. One 240V, 5A Socket shall be provided at a strategic

point inside the cabinet to facilitate connection of soldering iron during maintenance. Afterfabrication the entire enclosure shall be sand blasted to a SA 2 1/2 surface. An inorganic

zinc primer shall then be sprayed to a total thickness of 3 mils. The finish coat shall be adark grey shade of polyamide cured epoxy in three coats to achieve total thickness of 15mils.

3.1.16 ENCLOSURE EARTHING

All normally dead metallic parts shall be electrically continuous, earthing terminals shall besuitable for 35mm square cable connection, one earthing terminal shall be made for earthing


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connection to power supply earthing and two earthing terminals shall be made for earthingconnection to the local earthing pits.

The earth connection points shall be protected against corrosion. It shall not be necessary to

scrape the paint away in order to make an effective earth connection. Provision shall alsobe made adjacent to each gland plate for cable gland earthing connection.

3.1.16.1 Cable Terminations

i) Cable glanding and terminating facilities and terminals shall be suitable for the specifiedcable type and conductor size. Consideration and provision shall be taken by themanufacturer on the equipment design for the use of cables with aluminum conductors.

Cable glands & cable lugs shall be in the scope of supply for CP system installationcontractor.

ii) Terminal blocks shall be arranged and positioned to afford easy access for carrying outexternal cable termination, testing, inspection and maintenance. There shall be ample clear

space allowed between the terminal block and the gland plate for the spreading andtermination of external conductors.

iii) All terminal blocks shall be shrouded or provided with transparent covers. Pinch screwtype terminals are not acceptable.

iv) Three positive and three negative post type D.C output terminals shall be provided forthe T/R Unit. Each post shall be fitted with double nuts and washers.

v) Terminals for different voltages shall be separated by partitions.

vi) A terminal box or chamber with undrilled gland plate or entry panel of sufficientdimensions to terminate the specified incoming and outgoing cables shall be provided.

Direction of cable entry shall be from below.

vii) Termination of single core cables shall be through a non-magnetic metal panel or glandplate and provision made for bonding and earthing any armour and/ or concentric ground

conductors.

viii) Cable terminal arrangements for power and control cables may be integrated providedthat a barrier separates the two.

ix) Auxiliary wiring shall have copper conductors of the manufacturer's standard sizing(subject to Buyer’s approval).

x) Suitable terminals for two nos. ref. cell cables, one no. measurement cables and a selectorswitch for permanent ref. cell to be provided for T/R unit panel for connection to VSP

meter.


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Wiring shall be crimped using self-insulated compression type terminal blocks which shallbe suitably identified. Conductors shall be fitted with sleeve ferrules bearing the same

identification as the terminal to which they are connected. Minimum conductor size shallbe 1.0mm2 (current density shall not be more than 3A/mm2 for copper conductor).

3.1.17 NAME PLATE

A permanently stamped stainless steel metal plate shall be attached to outside of the casewith the following information.

a. Manufacturer's nameb. AC input voltage and current rating

c. AC frequencyd. Phase

e. Output DC volts and Amps. rating

f. Weight in Kg of T/R unith. Model number

i. Serial number j. Year of Manufacture

3.1.18 DATA SHEET OF 50V, 75A T/R UNIT

A. AC input voltage : 240 Volts +10% 50 Hz single phaseB. AC input Current : 33A(Max.)C. DC power output : 4.6 KW(Max.)

D. KVA rating of transformer : 7.7KVAE. DC output voltage : 50V

F. DC output current : 75AG. Current rating

- Diodes: 150A(Max. Average forward current)

- SCR : 85A (Average on state current), 133A (RMS on state current)H. Full load efficiency

- Transformer alone: More than 95%- Transformer Rectifier Assembly: More than 75%

I. Full load power factor:0.8 lagging

J. Insulation level: 2KVK. Peak Inverse Voltage

- Diodes/ SCR's : 1200V (PIV)

L. Filtering circuit: L.C filterM. Ripple and Hum at rated output: Not more than 5%

N. Surge Divertersi) For diodes/ SCR's : R-C circuitry of rating as advised by manufacturer of SCR/ Diodesii) For input of T/R unit : 2 nos. Zener Diodes of voltage rating 300V RMS, spark over

voltage 1000V (Peak), RIR Type A6 FMR 100 BB or equivalent MOV type surge diverters.iii) For output of T/R : 2 nos. Zener Diodes of voltage unit rating 300V RMS, Spark over

voltage 800V (Peak), RIR Type A6 FMR 80 or equivalent MOV type surge diverters.


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O. Lightening arrestor:

2 nos. each at the input and output of the T/R unit of voltage rating 280V RMS, Max. 1.2/ 50 micro Seconds impulse spark over voltage 2.5KV (Peak), Max. discharge residual

voltage at 5KA, 8/20 micro second impulse current wave 2.5KV @1.5KA, Max. impulsecurrent discharge capacity 4/10 micro second impulse current wave 10KA(Peak), LAMCOL.T-2.8 or equivalent make.

P. Protection : MCB suitable for motor load having thermal over load and magnetic short

circuit Protection for input current in addition to separate HRC fuse protection for eachDiode, HRC fuse at out put and input terminals, glass cartridge fuse, in the live line of alllamps, auxiliary power lines to control circuit and voltmeter circuits.

Q. Construction : Plinth mounted indoor type.

R. Cooling : Air cooled

S. Meters/ Instruments: As per Sec.3.1.13.

1 No. DC voltmeter 0-60V, 1 No. DC Ammeter 0-80A

1 No. AC voltmeter 0-300V1 No. AC Ammeter 0-50A

1 No. Corrosion voltmeter, 0-5000 mV, 10M ohm input resistance.

T. Enclosure:Per sec. 3.1.15

U. Cable entry: Through double compression Aluminum gland of following sizes of

cables. Gland plates are to be provided at the junction boxes located at both side of uppercompartment:

+ve and -ve header : 95mm2 /50mm2 1-core, 4nos.

Power supply cable : 25mm2

, 3-core, 1 No.

Monitoring cable : 6mm2, 1-core, 3 nos

(Monitoring cable to be used in case permanent ref. cell is used for monitoring pipe/

structure to soil potential )

V. Enclosure painting : As per sec. 3.1.15

W. Fabrication, Schematic: Supplier to furnish for EIL approval schematic wiring

diagram and fabrication drawing prior to fabrication of T/R units.

X. Spare parts & Additional features: Supply as per Sec.3.1.18.

Y. Ambient temp : 45 deg C


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Z. Type of control required in Auto mode: Constant current control and constantvoltage control (AVCC MODE)

3.1.19 DATA SHEET OF 75A, 75V T/R UNIT

A. A.C. input voltage single phase : 240 volts +10% 50 HzB. A.C.Input Current : 50A (max.)

C. D.C.Power output : 6.8 KW (Max.)D. KVA rating of transformer : 11.3KVA

E. D.C.output voltage : 75VF. D.C.output current : 75A

Rest same as 3.1.18 except in item(S) where DC Voltmeter rating shall be 0-80V in place of0-60V.

3.1.20 DATA SHEET OF 50A, 50V T/R UNIT

A. AC input voltage single phase : 240 volts +10% 50HZB. AC input current : 30A (max.)C. DC power output : 3.0KW (max.)

D. KVA rating of transformer : 5 KVAE. DC output voltage : 50V

F. DC output current : 50AG. Current rating SCR: 50A (Average on state current), 133A (RMS on state current)

Rest same as 3.1.18 except in item(s) where DC Ammeter rating shall be 0-60A in place of0-80A.

3.1.20 (a) DATA SHEET OF 25A, 25V T/R UNIT

A. AC input voltage single phase : 240 volts +10% 50HZB. AC input current : 5A (max.)

C. DC power output : 625W (max.)D. KVA rating of transformer : 2.5 KVAE. DC output voltage : 25V

F. DC output current : 25A

Rest same as 3.1.18.

3.1.21 Testing of T/R units

All T/R units shall be tested by contractor and inspected by EIL/ Owner before dispatch,

testing shall be conducted in accordance with codes and standards enclosed in thisdocument, as per routine tests done by manufacturer and additional tests as mentionedbelow:


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3.1.21.1 Efficiency test of Transformer Rectifier Assembly at 25%, 50%, 75% and100% rated output current both in Auto and manual mode of operation. Efficiency test of

Transformer alone after isolating rectifier at 100% rated output current.

3.1.21.2 No load output voltage test in Manual mode for each voltage setting usingcoarse and fine tap switches at rated input voltage of 240V AC.

3.1.21.3 Output voltage and current test in Manual mode for each voltage settingusing coarse and fine tap switches for the following conditions.

i) Input voltage 240V AC, load resistance 1.65ohm for 50A T/R & 1.1 ohm for 75A T/Rii) Input voltage 253 VAC, load resistance 1.65ohm for 50A T/R & 1.1ohm for 75A T/R

iii) Input voltage 207 VAC, load resistance 1.65ohm for 50A T/R & 1.1 ohm for 75A T/R.

3.1.21.4 Output voltage test at rated output current setting in Auto mode for the

following conditions.

i) Input voltage 240VAC, load resistance: 1.65ohm for 50A T/R & 1.1 ohm for 75A T/Rii)Input voltage 253 VAC, load resistance : 1.65ohm for 50A T/R & 1.1 ohm for 75A T/Riii) Input voltage 253 VAC, load resistance 0 ohm (short circuit across +ve and -ve terminal

of T/R unit). Set back up control 75A & 50A for 75A &50A T/R unit respectively.iv) Input voltage 207VAC, load resistance: 1.65 ohm for 50A T/R & 1.1 ohm for 75A T/R

Output current and voltage shall be recorded for each of above conditions (i) to (iv).

3.1.21.5 Heat run test for max. temp rise to be conducted for main transformer, Autotransformer, filter choke, Diodes and SCR's, at 50A output current for 50A T/R Unit & 75A

current for 75A T/R unit for 48 to 72 hours continuous operation. Number of T/R units tobe considered for Heat run tests and actual duration for which test to be conducted up to 72hours (max.) shall be decided by EIL and owner. Thermocouple instrument shall be used for

measurement of temperature. The sensors shall be clamped at different locations inside theclosed T/R unit cubical and the cable of the sensors shall be connected to temperature

indicator through a selector switch outside the T/R unit cubical during heat run test.

3.1.21.6 Insulation resistance test using 500V megger for Auto transformer and Main

transformer between primary and secondary, primary and earth, secondary and earth.

3.1.21.7 Dielectric strength test using 2KV for 1 min. duration for Auto transformer,main transformer between Primary and secondary, primary and earth, secondary and earth.

3.1.21.8 Polarity test in Auto and manual mode of operation of T/R unit.

3.1.21.9 Calibration test for all Ammeters and volt meters.

3.1.21.10 Auto mode over load protection test:

Set back up control at 40 Amp and increase current from zero to max. Possible using main

Auto control for T/R Unit having constant current control.


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In case of Auto PSP control T/R unit ref. feed back signal to be varied from min. to max.

set potential of T/R unit using battery & rheostat in place of ref. half cell signal, currentduring the test should not exceed more than 40A in both cases.

3.1.21.10.1 Constant Current Test

i) D.C Current Regulation against variation in AC Input

Put the unit in constant current mode and set the output current at 75 A by the help ofcurrent setting potentiome ter and observe the variation in, if any, of output current withvariation of AC input voltage at the steps keeping the output load constant: 216V, 240 V,

264 V.

ii) D.C Current Regulation against variation in Load Voltage

Keeping the AC input voltage at 240 V constant , set the output D.C current at 75 A and

observe for any variation of DC current with variation of output load voltage at threedifferent values ensuring that at each output load voltage, taking care voltage limit set valueis not exceeded.

Repeat the above at 50A and finally at 25A set output current.

3.1.21.11 Constant voltage test for control circuitory.

Supply voltage of T/R unit to be applied 240V 184V and 276V.

For each input supply voltage the reference voltage, +ve DC and -ve DC voltages of Automode control circuit to be checked whether they are constant.

3.1.21.11.1 D.C Voltage Regulation against variation in Load Current

Keeping the AC input Voltage at 220 V constant, set the output D.C voltage at 48 V andobserve for any variation of D.C Voltage

1.attachment-i- technical specifications - copie

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