16-samss-519

Previous Issue: 29 June 2005 Next Planned Update: 5 May 2012 of 10 Primary contact: Carlson, Ronald Wayne on 966-3-8746128

Copyright©Saudi Aramco 2007. All rights reserved.

Materials System Specification

16-SAMSS-519 6 May 2007 Indoor Switchboard - Low Voltage

Electrical Substations Equipment Standards Committee Members Ghamdi, Mohammed Ahmed, Chairman Carlson, Ronald Wayne, Vice Chairman Maghrabi, Ibrahim Mohammad Ramadhan, Mohammad Jafar Hartman, Ralph August Helfrich, Cory Allan Refai, Jobran Ali Stansbury, Merlin Chip Lowe, John Ojan, Jawad Ali Gopal, Uarutharaja Nazzawi, Abdullah Omar Fayez, Hamad Abdullah

Saudi Aramco DeskTop Standards Table of Contents 1 Scope............................................................ 2 2 Conflicts and Deviations............................... 2 3 References.................................................... 2 4 Definitions..................................................... 3 5 General......................................................... 4 6 Rating............................................................ 5 7 Service Conditions........................................ 5 8 Enclosures.................................................... 5 9 Conductors.................................................... 6 10 Grounding..................................................... 7 11 Switching Devices......................................... 7 12 Metering........................................................ 8 13 Nameplates................................................... 9

Document Responsibility: Electrical Substations Equipment 16-SAMSS-519 Issue Date: 6 May 2007 Next Planned Update: 5 May 2012 Indoor Switchboard - Low Voltage

of 10

1 Scope

This Specification defines the mandatory requirements for indoor, low voltage switchboards rated a maximum of 2000A and 600 V.

2 Conflicts and Deviations

2.1 If there are any conflicts between this Specification and associated purchasing, project or engineering documents, this specification shall take precedence.

2.2 Direct all requests to deviate from this Specification in writing to the Company or Buyer Representative, who shall follow internal company waiver procedure.

2.3 The designation "Commentary" is used to label a sub-paragraph that contains comments that are explanatory or advisory. These comments are not mandatory, except to the extent that they explain mandatory requirements contained in this SAMSS

3 References

The following is a summary of all the documents which have been mentioned within this Specification. The specific part(s) of these documents which are applicable have been identified throughout this Specification.

3.1 Saudi Aramco References

Saudi Aramco Materials System Specifications

16-SAMSS-518 Panelboard - Low Voltage

16-SAMSS-521 Indoor Transfer Switch - Low Voltage

3.2 Industry Codes and Standards

American National Standards Institute

ANSI C37.13 Standard for Low-Voltage AC Power Circuit Breakers used in Enclosures

National Electrical Manufacturers Association

NEMA 250 Enclosures for Electrical Equipment (1000 Volts Maximum)

NEMA AB 1 Molded Case Circuit Breakers and Molded Case Switches

NEMA PB 2 Deadfront Distribution Switchboards


of 10

National Fire Protection Association

ANSI/NFPA 70 National Electrical Code

Underwriters Laboratories, Inc.

UL 891 Safety Requirements for Switchboards

4 Definitions

Compression connectors: are connectors which are compressed onto the conductor using a die and high mechanical force. The process is not reversible and the connector becomes a permanent part of the conductor. The connector can only be removed from the conductor by either cutting the conductor or cutting the connector.

Conductor: All material, devices and parts which are expected to carry current as part of their normal function (e.g., cable, bus, relay contacts, terminal block studs, etc.).

Deadfront: As per the NEMA PB 2 definition, a switchboard which has no exposed live parts on the front.

Discrete: Device which only performs one function. For example, a discrete voltmeter only displays voltage.

Front Accessible: As per the NEMA PB 2 definition, a switchboard in which all bus and device connections are accessible from the front. If necessary, a limited number of devices shall be permitted to be removed to achieve this accessibility.

Low Voltage: Means a voltage level of less than 1000 volts.

Commentary Note:

For this equipment in the intended application "low voltage" is essentially limited to 600 V.

Main Circuit: All the conductive parts of an assembly included in a circuit which is intended to transmit electrical energy to the connected loads.

Main Circuit Disconnector: device to isolate the switchboard from the main incoming circuit.

Mechanical connectors: connectors which are attached onto the conductor using, generally, a standard tool. The process is reversible and the connector can be removed from the conductor without cutting the conductor or the connector.

Panelboard: equipment manufactured per the requirements of 16-SAMSS-518.


of 10

PEM: Parent Equipment Manufacturer. The manufacturer who designed the equipment and who confirmed the design performance through certified design/type tests. This manufacturer (1) has the legal authority to license the assembly of this equipment to others (2) is responsible for the technical performance of the equipment and (3) will be able to provide after-sales support and parts for the equipment.

Space: switching assemblies: are not equipped with a switching device but shall be developed to accept, with no modifications other than the installation of devices within the compartment door, a switching device suitable for a 125 kVA distribution transformer.

Spare: switching assemblies: are completely developed to serve the type of load indicated (i.e., including main switching devices, protective relaying, instrument and control transformers, control and auxiliary circuits, etc.) and shall be ready for operation when the feeder and control cables are connected. If the type of load is not specified, the load shall be assumed to be a 125 kVA distribution transformer.

Switchboard or assembly: The complete assemblage of switching assemblies as it will appear after installation by the Buyer.

Switching assembly: The assembly of switching devices and associated control and auxiliary equipment which controls or distributes power to a single load or via a single circuit.

Switching Device: A device designed to make or break current.

Transfer Switch: equipment manufactured per the requirements of 16-SAMSS-521.

5 General

5.1 Terms in bold font are defined within Section 3.

5.2 Refer to Section 2 for direction on conflict resolution between documents. For example, if there are any conflicts between this Specification and associated project or engineering documents, this specification shall take precedence.

5.3 Whenever this specification requires compliance to a third party document (e.g., ANSI, UL, etc.), this document shall be the edition which was in effect on the date of the Quotation Request.

5.4 All requirements of this specification must be implemented using standard designs which have been approved, have been fully tested and are fully supported by the PEM.

5.5 This specification shall take precedence over any referenced third party document.


of 10

5.6 Switchboards shall be manufactured per NFPA 70 (i.e., NEC) Article 384, UL 891 and NEMA PB 2.

5.7 All temperatures expressed within this specification are in Celsius units

6 Rating

6.1 Rated Duty: Continuous

6.2 Rated Current (maximum): 2000A

6.3 Short Circuit interrupting rating (minimum): 10 kA rms

7 Service Conditions

Switchboards shall be suitable for continuous operation under the following service conditions:

7.1 Ambient air temperature:

a) A maximum of 40 degrees.

b) A minimum of 0 degrees.

c) Average temperature, measured over a period of 1 month, is a maximum of 30 degrees.

7.2 Relative humidity (average value):

a) For a period of 24 hours, does not exceed 75%.

b) For a period of 1 month, does not exceed 70%.

7.3 Altitude is less than 1000 meters, unless a higher altitude is specified within Data Schedule 1.

8 Enclosures

8.1 Shall be front accessible, deadfront, completely enclosed, and free standing.

8.2 Enclosures shall meet the requirements of either Type 1, 2 or 5 per NEMA 250.

8.3 A space heater system shall not be installed within the switchboard enclosure(s).


of 10

9 Conductors

9.1 All conductors shall be copper, silver or alloys of these materials with the following exceptions:

9.1.1 Parts which are internal to a pre-manufactured device (e.g., internals of circuit breaker).

9.1.2 Connectors supplied as integral parts or components of manufactured equipment such as molded case circuit breakers provided the connectors are approved for copper conductors.

9.1.3 Plating of the copper, silver or copper/silver alloy base conductor material is acceptable.

9.2 All joints of the main circuit phase bus system shall be bolted with a minimum of two bolts as follows:

9.2.1 For overlapping joints, two bolts shall be provided.

9.2.2 For butt joints with splice plates, four bolts shall be provided (i.e., two bolts at each overlap).

9.3 Main circuit conductor system shall be copper and sized so the temperature rise does not exceed 65°C.

9.4 Bus bar mating surfaces shall be either silver or tin plated.

9.5 If a neutral has been specified, a full capacity neutral bus shall be provided.

9.6 The main circuit bus system shall be of rigid material (i.e., cable or flexible conductors shall not be used).

9.7 Conductors shall be terminated using either one or two hole, mechanical or compression connectors with the following exceptions:

Exceptions:

a) All wire/cable connections to the main circuit bus system shall be terminated using two hole compression connectors.

b) All wire/cable 250 MCM and larger or 120 mm² or larger shall be terminated using compression connectors.


of 10

10 Grounding

A ground bus shall be provided extending the full length of the switchboard. Bus design shall accommodate the termination of a two hole connector at each end of the bus.

11 Switching Devices

11.1 Breakers operating at greater than 240 V shall be equipped with padlockable lock-off devices.

11.2 If an incoming disconnect switch is provided, the switch assembly is not required to be withdrawable providing the open switch poles are visible with the compartment door open. The switch shall be padlockable in the OPEN position.

11.3 Circuit breakers with frame sizes exceeding 600-A shall be equipped with the following

11.3.1 Fully field maintainable (e.g., operating mechanism, pole contacts, etc.).

11.3.2 Equipped with a field adjustable electronic trip unit (i.e., "Type A" per NEMA AB1).

11.4 If a main circuit disconnector is provided, it shall be equipped with the following additional features:

11.4.1 Shall be withdrawable and padlockable in the fully withdrawn position. In this condition the compartment door shall be able to be closed to prevent a person from contacting any electrically energized parts.

11.4.2 Shall be equipped with adjustable instantaneous and inverse-time ground fault detection and tripping.

11.5 Switching assembly spare and space allotment shall be as follows:

11.5.1 A spare switching device shall be provided for every five devices of the same rating.

11.5.2 A minimum of one space shall be provided for every ten or portion of ten connected feeder circuits.

Commentary Note:

For example, assume the switchboard contained 6-225A breakers, 3-400A breakers and 3-150A breakers. 1 spare 225A switching assembly would be required to comply with paragraph 11.5.1.


of 10

2 spaces are required to comply with 11.5.2. Therefore, the switchboard would be equipped with 1 spare 225A breaker and 2 SPACES.

11.6 Ground fault protection shall not be installed on any incoming or outgoing circuits.

11.7 Low voltage panelboards installed within the switchboard shall comply with 16-SAMSS-518.

11.8 Transfer switch assemblies installed within the switchboard shall comply with 16-SAMSS-521.

12 Metering

12.1 Main incoming amperage and voltage metering shall be provided for each switchboard assembly. This metering shall have the following requirements:

a) Discrete voltmeter(s) shall display a voltage indication of all three phases (not necessarily all at once). These meters shall not require a control power to function.

b) Amperage indication shall be provided of all three phases (not necessarily all at once).

12.2 Discrete meters (e.g., ammeters, voltmeters, pf meters, etc.) shall not be installed within individual switching assemblies.

Discrete metering systems shall have the following characteristics:

a) 2% or better full scale accuracy.

b) Minimum overload capacity of:

i) 1.2 times measurement range continuously. ii) Ammeters: 10 times measurement range for 5 seconds. iii) Voltmeter: 2 times measurement range for 1 second.

c) Voltmeter/voltage input rating shall not be greater than 150 V.

d) Ammeter/amperage input rating shall not be greater than 25 A.

Exception: to 12.2. a) and b):

Ammeter monitoring the motor space heater system.


of 10

13 Nameplates

White Nameplates with black lettering shall be provided to identify the panelboard with the tag number indicated within Data Schedule 1.

Revision Summary 6 May 2007 Major revision.


of 10

Data Schedule 1

16-SAMSS-519: Indoor Switchboard – Low Voltage

(Information to be supplied to Supplier) Line # 1 Buyer's Quotation Request/ Purchase Order No.

______________________________________________________

2 Buyer's B.I./J.O. No.________, Line Item No.___________

3 Panelboard Tag No.__________________________

Service information:

20 As indicated on the attached reference documents ___ or the following:

33 System frequency: 60 Hz _____, 50 Hz _____

35 Number of Phases/Wires 1/2___, 1/3___, 3/3 ____, 3/4 ___

40 Rated Current: _______ A (2000A maximum)

41 Short Circuit Interrupting Rating: _________ kA (10kA minimum)

43 Rated voltage: _________ (600V maximum)

50 Incoming breaker required: YES ___, NO ____: If YES, trip rating ______ A

52 Neutral bus required: YES ___, NO ___

54 If YES, rated current of neutral bus as a % of phase bus: 100% ___, 200% ___

55 Site altitude (if greater than 1000 meters) _________ meters

56 Main circuit supply conductor connectors(if applicable):

57 Supplied by Supplier: YES ( ), NO ( )

58 If YES: No./phase and size of main circuit supply conductors:

59 _____ /ph., ______ AWG, MCM, mm²~!

16-samss-519

Documents