Pre-Commissioning TestsProcedure for SEC Transmission Electrical Installation

1.0 INTRODUCTION Proper pre-commissioning of new electrical equipment is important to prove that new equipment has been properly shipped and correctly erected and installed. This Procedure highlights the necessary steps related to proper pre-commissioning of new electrical equipment. As a general practice, all equipment is tested in the factory before delivery to the site. Pre-commissioning testing at site is done to prove that: No equipment was subjected to any damage during transportation. All equipment has been installed correctly. All equipment is working in coordination with other equipment, as specified. All the protection and control schemes are working in accordance with relevant specifications and

protection requirements. All equipment has been adjusted properly in accordance with approved settings. The installation is safe for putting into service.

1.1 Purpose

The main purpose of this procedure is

1.1.1 To provide guidelines to the witnessing engineer or technician to organize work at site during the pre-commissioning test period.

1.1.2 To provide the minimum tests to be performed on the equipment by the contractor, who has to prepare his work according to this Procedure.

1.2 Procedure

This Procedure is divided to two parts: the first part describes organizing the work at site before, during and after pre-commissioning tests. The second part concerns the mechanical checks, inspections and electrical tests to be performed on the equipment before commissioning the equipment into service.

PART I. ORGANIZATION OF THE WORK SITE FOR PRE-COMMISSIONING PART II. MECHANICAL TESTS, VISUAL INSPECTIONS AND ELECTRICAL TESTS

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PRE-COMMISSIONING TEST PROCEDURE

Index Number: T-PreCom-1000-R0

Revision Number: 00

Prepared By: Pre-Commissioning Committee

Original Issue Date: 2003-06-17

Revised By:

Revision Date:

Recommended By: Mohammad S. AL-Rafaa

Page Number: 1 of 124

Title:

PRE-COMMISSIONING TEST PROCEDURES FOR SEC

TRANSMISSION ELECTRICAL INSTALLATIONS Approved By: I.Y. Al-Hamoudi, Vice President CTA

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PRE-COMMISSIONING TEST PROCEDURE PART I

Title: PART I: ORGANIZATION OF THE WORK


SITE FOR PRE-COMMISSIONING Page Number: Page 2 of 124

1.0 INTRODUCTION Pre-commissioning tests for a new or reinforcement project are to be checked thoroughly and witnessed by SEC Commissioning engineer or technician. During the course of the commissioning it has been observed that at many stages the contractors are not ready and consequently the Commissioning personnel have to wait with the result that some tests may be missed or ignored. A procedure is required to check the complete readiness of the contractor before the pre-commissioning tests and prepare the commissioning engineer/technician for applying commissioning tests as per SEC commissioning Procedure. This document briefly outline the necessary steps to be followed to ensure that contractors are ready to start the pre -commissioning in order to reduce or maintain the approved project milestones and control the quality of the commissioning test. The main purpose of this procedure is to provide necessary guidelines to ensure the readiness of the contractors to start the pre-commissioning testing of new or reinforcement projects and how to apply and perform the pre-commissioning tests ensuring that: The project is ready for pre-commissioning tests. The contractor is fully equipped and ready from all aspects to start the pre-commissioning test. The time for witnessing the pre-commissioning tests is at minimum duration with high quality

performance. 2.0 PROCEDURES

2.1 Project Management Responsibility

Project Management shall confirm the readiness of the contractor from all aspects. A joint inspection shall be conducted with commissioning personnel and the contractor to ensure the contractors readiness to start the project after written confirmation is received from Project Management.

2.1.1 Contents of Confirmation Letter

The Confirmation Letter shall, at minimum, contain:

Equipment is installed and has been inspected and satisfied by the SEC Project

Quality section. Availability of contractors qualified manpower and testing engineers. Availability of tools and test equipment with one-year valid calibration certificate. Insulation Resistance test and pre check of all wiring. Stable power supply for testing The site is safe for testing. Approved relay settings and drawings. Site office as per SEC requirements. Over-all approved schedule along with approved outages. Substation HVAC system is in service; required for protection/control testing.

2.1.2 Joint Inspection

The contractor, Project Engineer and commissioning personnel shall visit the substation jointly two weeks prior to the start of the pre commissioning testing and the following points shall be confirmed.

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2.1.2.1 Site Office Facilities

The site office shall be complete with the following facilities:

Commissioning Group Room with working table, chairs, telephone, PC

and PC table. Conference room with conference table, chairs, white board, telephone

and notice board. Drawing/record room with filling cabinets and Operation and

Maintenance Manuals. Fax. Proper W.C. facilities are provided with raw water for washing. Kitchen with refrigerator.

2.1.2.2 Site Technical and Equipment Requirements

The following shall be available at site prior to precommissioning:

Confirmation Letter for verification of Section 2.1.1. Approved drawings, Scope of Work and one set of approved drawings

available for sole use of witnessing personnel. Catalogues, Operation and Maintenance Manuals, all relevant

specifications and protection requirements. Factory Test results. Approved site test procedures and format. Proper communication must be ready for SCADA if applicable. SCADA program is ready for implementation if applicable. Proper housekeeping and safety standards. Approved deviations List. Base and Detailed Design Comments.

3.0 WITNESSING COMMENCEMENT After confirmation of all the items of Section 2.1.2, witnessing can begin after two weeks.

3.1 Commissioning File The Commissioning engineer/technician shall have a Commissioning File for each substation; the File shall include at minimum: Single Line Diagram. Approved relay settings. Site Instructions. Weekly and overall Commissioning Schedule. Minutes of Meeting. Technical Specifications. Copy of approved deviations list and Base Design comments. 3.2 Site Instructions/Records and Project Punch List/Snags Rectifications Commissioning personnel are responsible for witnessing the pre-commissioning tests for reinforcement and new substations. During the course of witnessing, the necessary Site Instructions (S.I.) are issued which indicate the deficiencies in fulfilling SEC relevant Standards, SOW, workmanship, safety and common operation and maintenance problems. Sometimes differences have been noted in the S.I.s issued by different engineers on a particular point. Therefore guidelines are required for issuing S.I.s. This document briefly describes the

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guidelines to be followed by all Commissioning personnel to issue S.I.s in order to achieve uniformity and consistency. It should be kept in mind that this is a guideline only and it will not supercede any SEC relevant Specification in any manner.

3.3 Sequence of Events

Any items contrary to SEC Standards, SOW, workmanship and safety will be reflected in the deficiency section of the Register File, see Attachment No. 1. The Register File has two sections, one section belongs to the activities (Attachment No. 2) along with the single line diagram to help an engineer to visualize the project and the other section for the deficiencies. After one week from the registration of a deficiency in the book, all outstanding items will be sent to the Project Engineer via Site Instructions/Records (Attachment No. 3). Bi-weekly, the status of the punch list has to be issued by the contractor on the SEC format, Attachment No. 4. One month prior to the scheduled energizing of the equipment, the categorized deficiency list shall be issued by the commissioning personnel to identify the items which must be corrected prior to energization (Attachment No. 5).

ATTACHMENTS TABLE

ATTACHMENT

NO. DESCRIPTION REMARKS

1. Register Book/Deficiency Record

The Commissioning engineer/technician shall record all the items contravening safety, SEC Standards, Scope of Work and workmanship on the Deficiency Record.

2. Register Book/Activity Record

The Commissioning engineer/technician is responsible to daily update site activities to help any engineer to familiarize him with the status of the project.

3. Site Instructions After one week from recording in the Deficiency Record, incomplete items will conveyed to the Project Engineer via the Site Instructions Form.

4. Status of the Punch List

Bi-weekly the status of the punch list shall be updated by the contractor.

5. Categorization of the Punch List

One month prior to energizing the equipment, the categorized deficiency list shall be issued by the commissioning personnel to identify the items to be done before energization.

6. Pre-Commissioning Time Utilization Statistic Sheet

The commissioning engineer/technician shall fill in this sheet on a daily basis.

7. Final Pre-Commissioning Report

The Commissioning engineer/technician shall issue a final Pre- commissioning Report at the end of the project.

8. Sample Check (Optional Agreement)

In order to reduce the pre-Commissioning time the sample check procedure may be exercised based on the contractors previous performance and the last time utilizations status sheet. This shall be based on agreement between the contractor and SEC Transmission.

9. Check List The check list is intended to provide information to the commissioning engineer/technician who are assigned to inspect the contractors work and witness commissioning testing on behalf of SEC.

10. Contractors Performance Report

The commissioning engineer/technician shall fill this form at the end of the project to evaluate the performance of the contractor.

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4.0 ISSUING SITE INSTRUCTIONS/RECORDS Site Instructions (SI) shall conform to the following: The Site Instruction will be issued on a standard format, see Attachment 3. Every site instruction will be allocated with a number prefix and a letter P (Protection), S (Testing

of Substation Equipment), L (Overhead), U (Cable), O (Operations) and FM (HVAC, Building), etc., with date.

The S.I. will be issued to the site project engineer who will hand over the same to the contractor. Deficiencies in the drawing/literature, tools and test equipment, etc., shall be conveyed without

S.I. Number with one weeks notice and if not corrected within a week the same to be issued with an S.I. Number. This also shall be discussed with the section head for further guidance.

While issuing an S.I., necessary reference to the drawing No., sheet No., specification No., P.R. and design approval stage comments, etc., must be indicated.

A copy of the S.I. signed by the Project Engineer and Contractor will be kept in the commissioning file.

Some of the instructions although necessary, cannot be implemented due to Contractual terms, lack of wording in the Scope of Work, unclear P.R., etc., are to be filed with proper remarks in the respective substation file for implementation at a later stage. Such items shall be communicated to Engineering and Design Department for inclusion in future Projects.

The contents of the S.I. can be categorized under various headings as noted below. The common Snags/Punch list mentioned will be issued once in one S.I. for the whole substation and repetition of the same for different bays shall be avoided.

4.1 Equipment not fit for Service

This consists of the following deficiencies relating to protection, metering and control equipment.

Missing equipment. Physical damage to the equipment. Rating is not matching with relevant specifications. Equipment with internal fault causing incorrect test results. The equipment is not on the SEC Approved Manufacturers List.

4.2 Deviations from SEC Specifications Examples are listed as follows:

Protection or a part of it is not in line with SEC relevant Specifications and/or Protection

requirements. Work has not been executed in line with general requirements or has not had approval

during the design stage. Design comments have not been implemented for the protection scheme and other

equipment.

4.3 Poor Work Quality

Examples are listed as follows: Segregation of protection CT and VT cables is not maintained and color coded cables are

not used. Poor ferrule printing quality which will fade over time.

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Cables are directly terminated on terminal blocks without providing adequate clearances for access during troubleshooting or maintenance.

Equipment or terminals are not sufficiently accessible to allow maintenance. Ferruling method does not meet relevant specifications. Apparatus is not properly labeled. Wiring has either wrong ferrules or no ferrules. Improper use of terminal lugs. Control cables do not carry proper number tags. Proper wiring dressing has not been done in panels. Labels with incorrect spelling, uneven engraved letters, improperly aligned, letters too

small, badly cut edges, etc. Alarm annunciator labels/text with letters too small to read from a distance, and

acknowledge/reset/test push buttons at difficult to reach locations. Congested wiring obstructs other terminals on a terminal block. Very loose plug/socket arrangement. These should always be locking type. Improper locking of panel doors has caused frequent breaking of the panel door locking

mechanism. Adequate illumination does not reach all working places, terminals, in the panel, in front

of relays, etc. Terminals, auxiliary relays, flag relays mounted at very low level or very high level. Wiring not supported properly causing undue termination tension, which may result

eventually slipping of wire/breaking off from crimp. Bad crimping of wires. For CT circuit this is most dangerous as this may lead to open

circuiting of energized circuits. Open circuited energized CT circuits may cause fires and serious electrical hazards.

Inadequately rated relays used for continuously energized relays in fail safe, scheme, etc.

4.4 Improper Electrical Scheme

A protection scheme may not operate properly in spite of implementation of the relevant specification. Examples are listed as follows: Pole discrepancy in tripping of the required CBs. Alarm is not working, either locally or remotely. Problems with auto re-closing. Problem with the inter trip scheme. Absence of anti pumping operation. This can be dangerous if the anti pumping fails to

operate. D.C. supervision scheme is not working. Trip circuit supervision scheme is not working properly. Improper operation of auto switching (ABTS) scheme. Improper operation of distance relay accelerating scheme. Problems with closing selection, interlock wiring, close lockout relay elements. Relay flags not working properly due to mechanical problem or other reasons. Alarm does not operate due to very fast resetting of main protection relay contacts. Auto re-closing scheme does not work correctly due to like failure of synchrocheck relay,

inadequate duration of start pulse, etc. 4.5 Updating of Records

Examples are listed as follows: Equipment is missing from the apparatus list.

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Rating, contact arrangement and ordering number is incomplete. Cross-references are missing or incorrect. Correct catalogues have not been provided. Testing procedures are not available for some relays. Three copies of drawings are required to be updated for modifications and corrections,

using red for addition and green for deletion. This has not been done correctly. Proper test record forms are not available to record the test results. Some drawing sheets missing. Factory test results not available at site.

4.6 Common Punch List/Snags

The following Punch list/ snags are found repeatedly in substation construction. Most of them are clearly mentioned in the SEC Specifications/General Requirements. Irrespective of this fact, they are usually repeatedly discovered. When these types of points are raised at site, the contractor generally tries to avoid implementation. Every effort should be made to have the contractor promptly correct the inadequacies. Some examples are listed as follows: Color-coded cables shall be used for control and/or alarm functions and black ones shall

be used for CT, PT or AC circuits. Quality of printing and the placement of ferrules is poor in many cases. While terminating cables, the contractor does not leave any margin inside/outside the

panel for re-terminating the cables in another location in the same panel, in case it is required.

While laying cables, segregation is not maintained section-wise, so that in case of fire in one section the other sections will also be affected.

Paralleling of alarms is done with software, whereas it is necessary to do this with help of wiring for system reliability.

Equipment lists do not correlate with the installed equipment and details such as ordering number and the numbers of NO/NC contacts, etc., are not correct.

More than one earth point has been made for the CTs feeding the unit protection, e.g., Restricted Earth fault, Differential, Breaker Failure and Bus bar protection.

From the maintenance point of view the access to relay terminal blocks is very important; some contractors do not pay enough attention to this.

Positive (+), Negative (-) and trip marked in red are not provided on the relevant wires. Contractors do not allocate fault recorder channels as per SEC specifications. Site modifications are not properly reflected in the drawings. CT shorting and isolating arrangement is not in line with SEC standard arrangements

including shorting/isolating, instruction and caution notices. Lack of proper labeling to the protection and control equipment in different location, e.g.,

relay panels, control panels, LCC and AVC panels, AC/DC distribution boards, power transformer marshalling kiosks, CB isolators and earth switches, etc. This equipment includes main relays, auxiliary relays, contactors, trip relays, MCBs terminal blocks, points on the test switch (MMLG or ABB type), trip links and other links used for other specific functions.

CT and VT protection cables are not segregated. Terminal block wiring is too low for convenient access, especially CT shorting and

isolating switches. These shall be at working height level. Crimping of terminal lugs is not done properly, particularly for CT and VT wires. Length of the metallic part of CT and VT lugs is not enough to provide proper grip when

they are tightened in the terminal blocks.

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Plug in type miniature relays are used in tripping and interlock circuits. After a period of time, these relays do not function properly, due to displacement from their original position.

Normal earth switch was used on the line instead of high-speed type. In one substation, the backup main protection was found not working when the DC

supply to the first main protection was switched off since the isolator image was controlled by the first main DC supply.

Power cables for the fans from the AC distribution board to the transformer marshalling kiosk were found underrated.

Protection coordination of MCBs installed in the DC distribution board was not maintained, so the contacts of an ON/OFF switch were burnt due to a short circuit in the DC wiring.

During on-load checks 12 volts were observed across the CT terminals of feeder cable protection.

The manual mode status of the Halon was found not annunciated. As per SEC specifications it is necessary to install an independent synchrocheck relay for

manual and auto re-closing for each CB rated 110 kV and above. The bus-bar protection trip logic for double bus-bar substations does not conform with

SEC specifications. The annunciator output contacts did not follow the initiation when the input was reset as

per SEC specifications. Remote end breakers also trip in case the HV E/F relay of transformer operates. It

should only trip the local breaker. The A/R did not close the breaker when the D.E.F. tripped the breaker. It was due to the

tripping of the breaker in advance before the initiation of the A/R.) The phases R and B were found interchanged for the reactors. Two phases of earth switch were on one side of the CTs whereas the third one was on

the other side of CTs. CT polarity if it was left reversed on one of the spare feeders and the loading of the spare

feeder led to operation of BBP. The anti pumping circuit is not operational for CBs. This deficiency will lead to re-closing

of the CB on to fault when a long duration closing pulse is initiated. The pilot wire protection 87PW is commissioned with reverse pilot; this will lead to

indiscriminate tripping. The DEF relay for one circuit is commissioned with wrong direction this will lead to

indiscriminate tripping of the circuit. The following items were found missing:

Labeling of spare cores with cable numbers. Provision of 10 % spare terminal blocks in each relay panel, control panel, LCC, etc. Provision of 10 % spare annunciator windows. Provision of cover on emergency trip push button. Availability of proper lighting arrangement in 13.8 kV and 33 kV switchgear panels, relay panels, control panels, AVC panels, AC/DC panels and all marshalling kiosks. Proper test facility for indicating and recording meters. Test facility for indicating lamps. Provision of indicating lamp extractor tool. Labeling of the duty CT cores. Labeling of CT primary polarity, e.g., P1 and P2. CT neutral looping with metallic jumpers.

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Labeling of relays, pressure relief devices, oil temperature gauges and winding temperature gauges, etc. Blocking of spare plugs. Avoiding use of plug in connections and plug-in type auxiliary relays.

These problems will be updated regularly as needed 4.7 Clearing The Punch List/Snags

It is very important to clear the Punch List/Snag items as soon as possible after confirming their implementation. Sometimes it is very difficult to confirm their implementation once the substation is energized, if they are not cleared during the pre-commissioning stage. It is very useful that the witnessing engineer/technician keeps the site instruction records updated by putting his signature with date without any delay after inspecting and approving the relevant snag.

5.0 TIME AND QUALITY MANAGEMENT The following sections listed below elaborate the techniques to ensure that all equipment tests are done with optimal use of the time available.

5.1 Check List

The Check List is intended to provide information to commissioning personnel who are assigned to inspect the contractors work and witness commissioning testing on behalf of SEC to verify that substation and transmission line equipment and system are acceptable as per SEC- Standards and Specifications. The listing of commissioning checks and tests are based on the SEC- Commissioning Procedure T-PreCom-1000-01.

5.2 Time Utilization Statistic Sheet

A time utilization statistics sheet is being included in this Procedure. This sheet must be filled in daily. The contents of this sheet will be used for planning future projects by using the total time consumed. Moreover this sheet will also allow corrective measures to be taken to reduce the pre-commissioning time. The number of hours lost should be filled correctly, see Attachment No. 6. 5.3 Testing Schedule

In order to start witnessing after two weeks from confirmation, the contractor shall submit to SEC the testing schedule, giving details for each test of the time and the commissioning personnel required. Every week, the contractor shall submit a three-week testing program giving details of the previous weeks completed jobs and the current and following weeks proposed jobs. If in the previous week, some job was not completed, a reason for the deferral and its effect on the overall schedule should also be mentioned.

5.4 Marked Up Drawings

The contractor is responsible to provide enough qualified manpower to prepare three sets of marked-up drawings during the pre-commissioning testing period in order to expeditiously finalize the as-built drawings without using the substation marked-up drawing. The three copies of the marked up drawing shall be distributed as the following:

Substation copy for emergency usage Contractor copy to prepare the as-built drawing Maintenance Department library copy for as-built drawing verifications

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5.5 Sample Check (Optional)

In order to reduce the pre-Commissioning time, sample checks could be exercised based on the following criteria, see Attachment No. 8.

If the overall rating of the contractor performance in his immediately previous contract

was GOOD. If the hours lost due to the contractor is less than 5% of the work, for the last time

utilization statistic sheet. 6.0 FINAL PRE COMMISSIONING REPORT AND CONTRACTORS EVALUATION Project completion depends on the pre commissioning report, which has to be issued by the commissioning engineer/technician (Attachment No. 7). In case of separate contractors working on the same substation (lines and substation), the line-commissioning engineer/technician shall provide a copy of the final reports to the substation-commissioning engineer/technician and vise versa. Each commissioning engineer/technician shall evaluate the contractor at the end of the project, see Attachment No. 10.

6.1 Final Pre-Commissioning Report

The commissioning engineer/technician shall issue the Report based on but not limited to the following. The status of the Punch List (A, B) for which A refers to any deficiency requiring an

outage to clear it or equipment damage or a safety requirements. B is any deficiency other than A.

Marked up drawing are available at site in good condition. Emergency contact list provided. Operation spare parts are available. Operation and Maintenance Manuals are available. Test results provided. All site tests completed. Test completion and energization of station service transformer. Test completion and energization of HVAC.

6.2 Contractor Evaluation

The commissioning engineer/technician shall use SEC format to evaluate the contractor using the following criteria: Quality of the work. Availability of qualified manpower. Availability of proper tools and test equipment. Quality of supervision/testing engineer. Safety. Cooperation. Punctuality.

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7.0 IMPLEMENTATION The following steps need to be given special consideration, for implementation of this procedure:

An appropriate coordination is required with Project Management. The major problems must be reported to the Commissioning Manager/Senior Engineer for guidance. Every effort should be done to ensure that this procedure is implemented. This procedure shall be included in the Scope of Work. The contractor/Project Management Engineer shall return all the dismantled material to SEC store via CTA/DTA Project Department. It is recommended to store a Project Commissioning File, which includes critical Punch List/Snags, contractor evaluation, final commissioning report, single line diagram, Minutes of Meeting and Relay Setting Sheet in the substation.

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PRE-COMMISSIONING TEST PROCEDURE PART II

Title: MECHANICAL CHECKS, VISUAL INSPECTIONS


AND ELECTRICAL TESTS Page Number: Page 12 of 124

1.0 INTRODUCTION This Procedure describes the tests and checks to be performed during the pre-commissioning stage of SEC Transmission projects. It deals primarily with the pre-commissioning tests to be followed for protection schemes and main equipment such as cables, transformers and switchgear, etc., keeping in view the SEC standard practices for various types of tests. Further, this listing of tests and checks is based on the requirements and recommendations of international standards such as IEC, ANSI, etc. They are the minimum tests and checks to be performed during pre-commissioning. 2.0 PURPOSE The main purpose of this Procedure is to present a list of checks and tests to be performed on transmission equipment. They shall be performed by the project contractor and witnessed by SEC Precommissioning personnel. 3.0 PROCEDURE

ITEM NUMBER EQUIPMENT 3.1 Oil Filled Power Transformers 3.2 Shunt Reactors 3.3 Bushings Inspection and Testing 3.4 Surge Arrestors 3.5 Station Service Transformers 3.6 Neutral Earthing Resistors 3.7 Current Transformers 3.8 Potential Transformers 3.9 Capacitive Voltage Transformers

3.10 Coupling Capacitor Voltage Transformer s 3.11 Gas Insulated Switchgear (GIS) 3.12 Metal Clad Switchgear 3.13 Metal Enclosed Bus Duct 3.14 Indoor and Outdoor Bus Structures 3.15 Indoor Circuit Breakers 3.16 Outdoor Circuit Breakers 3.17 Disconnect and Grounding Switches 3.18 Circuit Switchers 3.19 LV Switchgear (110/220 V) 3.20 230 kV and 380 kV XLPE Cables 3.21 230 kV and 380 kV LPOF Cables 3.22 110 kV, 115 kV and 132 kV XLPE Cables 3.23 110 kV, 115 kV and 132 kV LPOF Cables 3.24 69 kV XLPE Cables 3.25 13.8 kV and 33 kV XLPE Cables 3.26 LV Cables 3.27 Control Cables 3.28 Pilot Cables 3.29 Over Head Lines 3.30 Protection and Control 3.31 Substation Batteries 3.32 Battery Chargers 3.33 AC Distribution Panels 3.34 DC Distribution Panels

40224Battery Chargers

40224LV Cables

40224110 kV, 115 kV and 132 kV LPOF Cables

40224Coupling Capacitor Voltage Transformer s

40224Potential Transformers

40224Current Transformers

40224Neutral Earthing Resistors

40224Station Service Transformers

40224Surge Arrestors

40224Bushings Inspection and Testing

40224Oil Filled Power Transformers



40224Shunt Reactors

40224Bushings Inspection and Testing

40224Capacitive Voltage Transformers

40224Coupling Capacitor Voltage Transformer s

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3.35 LVAC Auto-Transfer Schemes/Switches 3.36 Grounding Systems3.37 Switchgear Air Compressor Systems 3.38 HVAC Systems 3.39 Dry Transformers 3.40 Fire Detection and Suppression Systems 4.41 Civil Work 4.42 Static VAR Compensation Systems

40224LVAC Auto-Transfer Schemes/Switches

40224Grounding Systems

40224HVAC Systems

40224Dry Transformers

40224Fire Detection and Suppression Systems

40224Civil Work

40224Static VAR Compensation Systems

40224Civil Work

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3.1 Oil Filled Power Transformers (Standard Reference is IEC 60076 and relevant SEC Transmission Specifications)

3.1.1 Mechanical Checks and Visual Inspections

ITEM DESCRIPTION REMARKS

1. Check the impact recorder for any abnormal impact during transit.

2. Check all components are installed. 3. Check for quality of paint, lifting lugs, quality of weld areas, rust

spots and wheel stoppers.

4. Check nameplates information (visible location) as per contract specifications.

5. Check tightness of all bolts (torque wrench method). 6. Check that all grounding is securely connected (two grounding

connections to main tank are required).

7. Check that the piping to Buchholz relay has proper slope. 8. Check that the tank pressure is positive, if applicable. 9. Check that the valves between the main tank and radiators are

open.

10. Check the HV, LV and TV (if applicable) bushings for damage and completeness.

11. Check for correct color and quantity of desiccant (moisture absorbing media) in breathers. Check for correct breather oil levels.

12. Check heaters and humidity meters in local panel are at correct settings.

13. Check that phase marking in cable box matches with GIS and cables.

14. Check all pipes, hoses and fan protection (not rubber or plastic). 15. Check the vertical and horizontal clearances of live parts to

adjacent grounded points conform to standard.

16. Check integrity of diaphragm/air bag in the conservator. 17. Perform all of the manufacturers specific checks. 18. Check labeling of all auxiliary devices as per approved drawing. 19. Check proper operation of auxiliary devices as follows:

a. b. c. d. e. f. g. h.

i. j. k. l.

Cooling fans/pumps (for all settings). Tap changer (upperlowerout of step and interlock). Oil level gauges. Top oil temperature gauges. Buchholz relay by gas injection. Winding temperature gauges. OLTC oil/gas surge (pressure) relay. Ensure correct operation of the Pressure Relief Device microswitch. Push buttons and indicators. Oil sampling port (main tank and OLTC). Upper and lower main tank valves. Tap changer diverter switch compartment, oil filtering pumps and filter in good condition (if available).

20. Check oil leakage; if any noted, apply 0.35 kPa over pressure for 24 hrs to make sure.

21. Check that the oil sampling valves for the main tank and OLTC

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are accessible from ground level. 22. Check oil level in main tank, conservator, tap changer tank and

bushings, etc. Test the oil level gauges and their alarms.

23. Bleed trapped air at the bushing turrets and radiators. 24. Check flow of oil in flow meter in correct direction and proper

rate (if applicable).

26. Check all external wiring for correctness and tightness. 27. Check on-line insulating oil dissolved gas and moisture

monitoring system (if installed).

3.1.2 Electrical Tests


1. Core Insulation Resistance Test. 2. Winding Insulation Resistance Test and Polarization Index Test

at 5 kV DC.

3. Winding Resistance Test (all taps). 4. Excitation Current measurements from primary side at each tap

during ratio test and from secondary side when energized from secondary terminals keeping primary side open or winding excitation current measurement test at 10 kV during power factor testing.

5. Insulation power factor and bushing test at 10 kV AC. 6. Vector Relationship Test. 7. Winding temperature device test by heating the sensor in oil

bath and checking against standard thermometer. Also check by current injection. Setting as per approved drawing to be applied and tested.

8. Oil temperature device to be calibrated by heating in oil bath. Setting as per approved drawing to be applied and tested.

9. Percent Impedance test at nominal tap. 10. Turn Ratio (all taps). 11 Check for current and voltage ratings of all motors for tap

changer and fans match to SEC standard supply. Check that MCBs for protection are set at proper over load settings.

12. Fan motor currents shall be measured and checked against rating. Check wiring size is adequate to carry the current.

13. Check that the phase sequence of supply voltage to fan motors is correct. Check fan rotation direction and confirm air flow is towards radiator.

14. MCBs in cooler control cubicle to be checked by current injection for alarm and trip.

15. On load Tap Changer tests: a. Check current and voltage ratings of tap changer

motor. b. Raise/Lower Control (localremote) and indication, and

perform adjustment as required. c. End of tap travel control. d. End of winding travel control (both ends). e. AVR setting of bandwidth, mid point, time delay, etc.,

and adjust as per approved setting. f. Master/Slave check out of step blocking alarm. g. Master/Slave control check either transformer as

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master. h. Parallel Operation Disturbedcheck alarm. i. Check that the windings are not open circuited during

tap changing. This should be done during the winding resistance test.

16. Bushing Current Transformer Tests: a. Polarity. b. Insulation Resistance. c. Secondary Winding Resistance (all windings and all

taps). d. Current Ratio (inject current) e. Magnetization Characteristics (minimum five points

below and two points above the knee point). f. Verify secondary circuits, terminal to terminal. g. Burden Test.

Demagnetize CT cores after all tests. Ensure no open circuit on CT secondary side.

17 Functional Checks for the Following: a. Liquid level (alarm and trip). b. Top Oil Temperature Device: fans/pumps (stop, start

alarm and trip). c. Winding Temperature Device. d. Buchholz Relay (alarm and trip). e. Oil / Gas Surge (pressure) relay (alarm and trip). f. Pressure Relief Device (alarm and trip)

18. Insulating Oil Tests: Prior to energization, the contractor shall submit insulating oil test reports tested at an independent laboratory, for the following:

a. Dielectric Strength i. ASTM D 877 (2.5 mm gap) for unprocessed oil

and for OLTC oil ii. ASTM D 1816 (1.0 mm gap) for oil in main

tank b. Neutralization Number (ASTM D 974) c. Interfacial Tension (ASTM D 971) d. Color (ASTM D 1500) e. Moisture Content (ASTM D 1533) f. Power Factor Test (ASTM D 924) g. Dissolved Gas in Oil Analysis (ASTM D3 612) h. (Dielectric Dissipation Factor, Resistivity, Sediment

and/or Precipitable Sludge). Another oil sample shall be given to SEC transmission for their own analysis and comparison purposes. A syringe oil sample shall be taken by contractor.

19. A main tank insulation oil sample for dissolved gas analysis shall be taken immediately prior to first energizing a power transformer and another sample three days after continuous energization.

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3.2 Shunt Reactors (Standard Reference is IEC 60076 and relevant SEC Transmission Specifications)



1. Check the impact recorder for any abnormal impact during transit.

2. Check all components are installed. 3. Check for quality of paint, lifting lugs, quality of weld areas, rust

spots and wheel stoppers.

4. Check nameplates information (visible location) as per contract specifications.

5. Check tightness of all bolts (torque wrench method). 6. Check that all grounding is securely connected (two grounding

connections to main tank are required).

7. Check that the piping to Buchholz relay has proper slope. 8. Check that the tank pressure is positive, if applicable. 9. Check that the valves between the main tank and radiators are

open.

10. Check the bushings for any damage and completeness. 11. Check for correct color and quantity of desiccant (moisture

absorbing media) in breather. Check for correct breather oil level.

12. Check heaters and humidity meters in local panel are at correct settings.

13. Check that phase marking in cable box matches with GIS and cables.

14. Check all pipes, hoses and fan protection (not rubber or plastic). 15. Check the vertical and horizontal clearances of live parts to

adjacent grounded points conform to standard.

16. Check integrity of diaphragm/air bag in the conservator. 17. Perform all of the manufacturers specific checks. 18. Check labeling of all auxiliary devices as per approved drawing. 19. Check proper operation of auxiliary devices as follows:

a. Cooling fans/pumps (for all settings). b. Oil level gauges. c. Top oil temperature gauges. d. Buchholz relay by gas injection. e. Winding temperature gauges. f. Ensure correct operation of the Pressure Relief Device

microswitch. g. Push buttons and indicators. h. Oil sampling port (main tank). i. Upper and lower main tank valves.

20. Check oil leakage; if any noted, apply 0.35 kPa over pressure for 24 hrs to make sure.

21. Check that the oil sampling valves for the main tank are accessible from ground level.

22. Check oil level in main tank, conservator and bushings, etc. Test the oil level gauges and their alarms.

23. Bleed trapped air at the bushing turrets and radiators. 24. Check all external wiring for correctness and tightness.

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1. Core Insulation Resistance Test 2. Winding Insulation Resistance Measurement Test and

Polarization Index (P.I.) Test at 5 kV DC.

3. Winding Resistance Test. 4. Inductance Measurement. 5. Impedance Measurement. 6. Winding temperature device test by heating the sensor in oil

bath and checking against standard thermometer. Also check by current injection. Setting as per approved drawing to be applied and tested.

7. Oil temperature device to be calibrated by heating in oil bath. Setting as per approved drawing to be applied and tested.

8. Insulation power factor and bushing test at 10 kV AC. 9. Bushing Current Transformer Tests:

a. Polarity. b. Insulation Resistance. c. Secondary Winding Resistance (all windings and all

taps). d. Current Ratio (inject current) e. Magnetization Characteristics (minimum five points

below and two points above the knee point). f. Verify secondary circuits, terminal to terminal. g. Burden Test.

Demagnetize CT cores after all tests. Ensure no open circuit on CT secondary side.

10. Functional Checks for the Following: a. Liquid level (alarm and trip). b. Top Oil Temperature Device: fans/pumps (stop, start

alarm and trip). c. Winding Temperature Device. d. Buchholz Relay (alarm and trip). e. Pressure Relief Device (alarm and trip)

11. Insulating Oil Tests: Prior to energization, the contractor should submit insulating oil test reports tested at an independent laboratory, for the following:

a. Dielectric Strength i. ASTM D 877 (2.5 mm gap) for unprocessed oil ii. ASTM D 1816 (1.0 mm gap) for oil in main


and/or Precipitable Sludge). Another oil sample shall be given to SEC transmission for their own analysis and comparison purposes. A syringe oil sample

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shall be taken by contractor. 12. Cooling system checks and measure for fan motors and pumps

(as applicable), etc., for current, supply voltage and air flow direction.

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3.3 Bushings Inspection and Testing (Standard Reference is IEC 60137 and relevant SEC Transmission Specifications)


1. Cleaning the insulator surface. 2. Check for tightness test between transformer and bushing

flange and outer terminal.

3. Visually inspect for any damage or cracks. 4. Check for leakage. 5. Check and adjust of oil level. Note that adding insulating oil to a

bushing shall be done under vacuum.

6. Measurement of capacitance and tan delta. The bushing shall be tested in a vertical position and the lower portion set into an oil reservoir.

7. Check of through resistance.

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3.4 Surge Arrestors (Standard Reference is relevant SEC Transmission Specifications)

3.4.1 Mechanical Checks and Visual Inspection:


1. Inspect for physical damage or defects. 2. Check tightness of all bolted connections (torque wrench

method).

3. For multi-unit stacks, check that the physical arrangement of the units are erected according to the manufacturers specifications.

4. Check that all grounding cables are correctly and secured connected.

5. Check name plate information for correctness as per SECs specifications.

6. Check that impulse counter and leakage current meter glasses are not broken or cracked.



1. Check calibration of leakage current meters. 2. Insulation resistance test at 5 kV DC. 3. Power factor test at 10 kV AC.

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3.5 Station Service Transformers (less than 2 MVA) (Standard Reference is relevant SEC Transmission Specifications)

3.5.1 Mechanical Checks and Visual Inspection


1. Check the Impact recorder for any abnormal impacts during transit (if applicable).

2. Check earthing, color, painting, external damage, oil leakage, wheel stopper, cable connection and bolt tightness, etc.

3. Check nameplate data against contract specifications. 4. Perform all special checks according to the manufacturers

instructions.

5. Check oil level in HV side cable box and its oil level indicator or HV fuses.

6. Check all devices are labeled correctly as per drawing.


ITEM DESCRIPTION REMARKS 1. Check LV side MCB setting as per transformer current rating 2. Ratio Test (all taps), Insulation resistance measurement test on

all windings and polarization index (P.I.) test.

3. Polarity and Vector Group symbols confirmation Test. 4. Check oil level and its indicator alarms. 5. Check oil temperature gauge by oil bath method and its alarms. 6. Check LV and HV side phases match with the LV bus bar

phasing in the distribution panels and with the main transformer phases.

7. Check phasing at the automatic transfer switch (as applicable ) 8. Winding resistance measurement (at all taps). 9. Excitation current test (all taps).

10. Back energization test at rated voltage for 15 minutes. 11. Check that the off load tap changer is set at the nominal voltage

tap.

12. Perform functional tests of all auxiliary devices (as applicable ) 13. Insulating Oil Tests:

Prior to energization, the contractor should submit insulating oil test reports tested at an independent laboratory, for the following:

a. Dielectric Strength i. ASTM D 877 (2.5 mm gap) for unprocessed oil ii. ASTM D 1816 (1.0 mm gap) for oil in main


and/or Precipitable Sludge).

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Another oil sample shall be given to SEC transmission for their own analysis and comparison purposes. . A syringe oil sample shall be taken by contractor.

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3.6 Neutral Earthing Resistors (Standard Reference is Manufacturers Instructions)


1. Check the value of resistance and current ratings against specifications.

2. Check that the external earth connection to main earth is copper wire at least 240 mm2 in size.

3. Test NER HV side associated CT and power cable. 4. Visually inspect the interior for broken insulators. 5. Measure the main circuit resistance. 6. Insulation Resistance Test. >=1000 megaohms 7. Ensure that the interior and exterior of the NER is clean prior to

energization.

8. Check identification and function of NER isolator (if applicable).

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3.7 Current Transformers (Standard Reference is IEC 60044-1 and relevant SEC Transmission Specifications) Note that Bushing current transformer tests and inspections are covered in the sections relating to the equipment into which they are installed.



1. Inspect for physical damage or defects. 2. Check nameplate information for correctness. 3. Check that outdoor secondary wiring terminations are installed

in moisture proof enclosures.

4. Check tightness of all bolted connections (torque wrench method).

5. Check that all grounding cables are securely connected. 6. Check secondary wiring is correctly color coded and size of

wires is as specified.

7. Check proper lugs have been used on terminations. 8. Check CT locations physically and secondary terminal labeling

has been done correctly.



1. Insulation resistance test. 2. Winding resistance measurement. 3. Polarity test or flick test with battery. 4. Ratio test by current primary injection. 5. Magnetizing current test (minimum two points above knee

point).

6. Loop resistance measurement test (burden test). 7. Phase identification test. 8. Verify secondary circuits, terminals, shorting/isolating links by

primary injection of CTs.

9. Insulation power factor test (live tank CTs-110 kV and above if applicable).

10. High voltage test: During normal HV tests on switchgear or GIS the CTs are included in the HV test. CT secondaries shall be shorted to ground and isolated from relays and meters.

11. Test intercore coupling for all bus differential CTs. 12. Demagnetize CT cores after all tests.

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3.8 Potential Transformers (Standard Reference is IEC 60044-2 and relevant SEC Transmission Specifications)



1. Inspect for physical damage or defects. 2. Check nameplate information for correctness. 3. Check tightness of all bolted connection. 4. Check that the HV connection does not transfer stress to the HV

terminal.

5. Check that all grounding cables are securely connected. 6. Check mechanical clearances and proper operation of all

isolation and grounding devices (as applicable).

7. Check integrity of primary fuses (if applicable). 8. Check insulation liquid level (if applicable). 9. Gas leakage check for GIS VTs.



1. Winding Resistance Test. 2. Insulation resistance tests HV TO G, LV TO G and HV TO LV

using a one kV insulation tester.

3. Ratio Test. 4. Polarity Test. 5. Primary and secondary fuses rating checks for 11 kV VTs and

above (if applicable).

6. Ensure VT is included in switchgear and GIS high voltage test. Test voltage is 1.5Uo (where Uo is -N voltage) for 1 minute For electromagnetic VTs, see Table 1.

7. Check VT HV neutral is solidly grounded. 8. Check electrical operation of all isolating and grounding devices

(if applicable).

9. Check phase sequence, for the final three-phase assembly. 10. Verify secondary circuits, terminal to terminal for correctness

and tightness.

11. Loop resistance test and burden test. 12. Check gaps of protective flashover devices (if applicable). 13. Insulation power factor test, 110 kV and above. 14. Back energization test at rated voltage for 15 minutes.

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TABLE 1

SYSTEM RATED VOLTAGE (KV)

RATED LOAD FACTOR

TEST VOLTAGE (KV) FREQUENCY TIME PERIOD REMARKS

11 1.5 9.5 13.8 1.5 12 33 1.5 28 69 1.5 60

110 1.5 95 115 1.5 99.5 132 1.5 114 230 1.5 199 380 1.5 329

60 Hz

I Minute

These tests are applicable to

electromagnetic VTs

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3.9 Capacitive Voltage Transformers (Standard Reference is IEC 60044-5 and relevant SEC Transmission Specifications)



1. Inspect for physical damage or defects. 2. Check nameplate information for correctness. 3. Check tightness of all bolted connections. 4. Check that all grounding cables are securely connected. 5. Check mechanical clearances and proper operation of all

isolation and grounding devices (as applicable).

6. Check oil level (if applicable). 7. Check for oil leakage. 8. Check electromagnetic unit spark gaps for correct setting (if

applicable).

9. Check drain coils (if applicable).


ITEM DESCRIPTION REMARKS 1. Winding Resistance Test. 2. Insulation resistance tests HV TO G, LV TO G and HV TO LV


3. Ratio Test. 4. Polarity Test. 5. Check HV neutral is solidly grounded. 6. Check electrical operation of all isolating and grounding devices

(if applicable).

7. Check phase sequence, for the final three-phase assembly. 8. Loop resistance and burden tests. 9. Capacitance and dissipation factor measurement tests.

10. Insulation power factor test, 110 kV and above. 11. Check on fast damping device (FDD).

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3.10 Coupling Capacitor Voltage Transformer (Standard Reference is IEC 60044-5 and relevant SEC Transmission Specifications)



1. Inspect for physical damage or defects. 2. Check nameplate information for correctness. 3. Check tightness of all bolted connections. 4. Check that all grounding cables are securely connected. 5. Check mechanical clearances and proper operation of all

isolating, grounding and shorting devices (as applicable).

6. Check electromagnetic unit spark gaps for correct setting (if applicable).

7. Check drain coil unit spark gaps for correct setting (if applicable).

8. Check wave trap mechanical assembly, bird screens, etc.


ITEM DESCRIPTION REMARKS 1. Winding resistance test 2. Insulation resistance tests HV TO G, LV TO G and HV TO LV


3. Ratio test 4. Polarity test 5. Check electrical operation of all isolating and grounding devices

(if applicable)

6. Check phase sequence, for the final three-phase assembly. 7. Loop resistance and burden tests. 8. Capacitance and dissipation factor measurement tests. 9. Insulation power factor test, 110 kV and above.

10. Perform all specific tests per manufacturers instruction 11. Phase angle check if the equipment is assembled at site.

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3.11 Gas Insulated Switchgear (GIS) (Standard Reference is IEC 62271-203 and relevant SEC Transmission Specifications)



1. Inspect for physical damage or defects. 2. Check nameplate information for correctness. 3. Inspect enclosures for proper alignment and foundation fixing

and grounding.

4. Check quality of paintwork. 5. Ensure that all special tools and equipment are provided as

specified and have proper storage.

6. Ensure that gas-handling cart (if provided) operates correctly and that special filling and degassing fittings are provided and have proper storage.

7. Verify that all lifting devices are correctly labeled for lifting capability.

8. Ensure that adequate ladders and walkways are provided for access to meters, filling ports, cranes, lights, etc.

9. Check and verify that all grounding of GIS is as per approved layout drawings and specification and is securely connected.

10. Check that all specified grounding switches are insulated, with removable grounding links.

11. Check operation of all mechanical interlocks. 12. Check tightness of all bolted connections (torque wrench

method).

13. Check each gas section filled to correct rated pressure. 14. Check SF6 gas at each gas section for air and moisture content

after filling at rated pressure. Permissible Dew Point is -35 C or lower.

15. Gas leak test of all flanges and joints after erection and filling. Wrap all joints with sealed plastic sheeting and test for gas leakage after 24 hours.

16. Calibrate gas pressure (density) gauges. Check the gauges have correct, legible and readable scales.

17. Check the gauges are ambient temperature compensated. 18. Check operation of all gas density switches (alarm trip signals

and lockout functions). Confirm correct set points.

19. Check all wiring is correct according to approved drawings or confirm the correctness of all modifications.

20. Verify that all front panel mounted devices (meters, push buttons, switches, indicator lamps, mimic buses, etc.) are installed as per drawings, fixed permanently and are correctly labeled.

21. Verify that all operating devices are correctly labeled. 22. Perform mechanical checks and visual inspections on all

component equipment: a. Circuit breakers. b. Current transformers. c. Voltage transformers. d. Disconnect and grounding switches.

23. Check that all phase marking and circuit labeling have been installed as per specifications.

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24. Ensure that all disconnect switches are provided with viewing windows or mechanical indicators for verification of contact positions and that all grounding switch positions can be visually verified.

25. Verify that correct Dispatch Numbers have been installed. 27. Check the closed barriers at the ends of each gas zones are

externally colored yellow or orange. The zone gas density gauges shall have a zone marking plates fixed over the gauges.

28. Check GIS over pressure relief discs are not cracked or deformed.



1. Insulation resistance test for all low voltage wiring and cabling. 2. Functional test of all controls and interlocks. 3. Resistance of all ground connection joints at 100 A DC. 4. Resistance of bus joints at 100 amperes DC. 5. Overall resistance of the main circuit. Not more than 1.2 X Rdesign with

components (CBs, disconnects, etc.) in closed position.

6. Functional check of all alarms, interlocking and indication circuits from the switchgear through to the local control cubicle.

7. CB Timing Test (open and close) with contact travel and speed analysis.

8. Disconnect switch close and open time tests for the confirmation of early make and late break operation of auxiliary contacts with main contacts for CT switching schemes.

9. Checks on CB hydraulic system or vacuum system for pump start stop trip/close lockout threshold values.

10. GIS PTs to be included during AC HV tests on GIS when test frequency is well above rated frequency, otherwise test at 1.5Un one minute at rated frequency without secondary load. PT secondary output volts shall be monitored during the high voltage test.

11. All AC/DC MCBS shall be tested by trip test through current injection.

12. Check and confirm GIS PTs primary isolation device with manual operation provided where fitted, along with its monitoring system locally as well as on mimic diagram in control room. Check VT HV neutrals externally available especially in case of VTS installed directly on cable feeder.

13. Check and confirm that the three-phase test adaptor and bushing for HV test on GIS has been provided.

14. Verify the alarms being initiated by SF6 density gauges on LCC and up to control room during calibration process.

15. Check that all cubicle space heaters and thermostats are functional and at correct temperature control settings.

16. Perform all electrical tests on following GIS components as per manufacturers instructions and SEC approved procedures.

Circuit breakers. Current transformers. Voltage transformers.

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Disconnect and grounding switches. 17. Perform high voltage test at 10 kV AC for 1 minute on all

grounding switches external insulating bushings.

I. HV Tests on GIS Main Circuits AC HV tests on main circuit of GIS are performed with all CBs and disconnect switches in the closed position at 80% of the factory routine test voltage for one minute. Partial discharge measurements (If applicable and possible to be performed) are performed at 1.2 X Un (Un = phase to neutral voltage). II. Preparation for HV Tests Check and confirm following points and condition to be met before high voltage tests.

i. The Switchgear shall be erected completely and filled with gas at rated pressure. ii. Some part may be disconnected before test, such as:

High Voltage cables and overhead lines. Power transformer and most voltage transformers. Surge arrestors and protective spark gaps. Current transformer secondary windings should be shorted and grounded.

iii. Every newly erected part of GIS shall be tested with high voltage. iv. The test should be performed at rated frequency (60 Hz.). If such arrangement is not

possible, then the frequency should be limited to the range of 30 to 300 Hz. v. AC voltage tests are sensitive in detecting contamination and abnormal field

configuration. vi. Tests with switching impulse voltages are useful especially for high rated voltage to

detect the presence of contamination as well as abnormal field configuration III. Two Test Procedures are Utilized to Test the GIS Contractor can adopt one of the two procedures A or B to perform high voltage test on GIS after erection at site

i. Procedure A

Site AC test voltage level shall be equal to the 80% of the factory routine test voltage. This test may be performed through series resonance method Or by a test transformer with sufficient capacity. PD measurements are possible to be measured

in this case at test voltage level = 1.2 Un (Un = phase to neutral rated voltage) during the HV Test process.

Electrical conditioning at voltage equal to U/3 for longer period such as 30 minutes may be performed to move and trap the contamination in areas where they become harmless.

Partial discharge measurements may be helpful in detecting some kind of faults.

ii. Procedure (B)

a. Through GIS Voltage Transformers

Site AC test voltage level equal to 1.2 Un for 5 minutes followed by Impulse Voltage test at a test level equal to 64% of the rated lightening impulse withstand level specified in IEC-517. Three positive and three negative polarity impulses shall be applied. b. With Separate Source

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In case the GIS VTs are not suitable to be used as test transformer; a special voltage transformer shall be used to perform such tests. GIS VT can only be used as a test transformer if the manufacturer guarantees its safety and capability to perform such tests otherwise it shall not be used as a test source.

IV. Deviation Due to Practical Needs Sometime in extension projects due to practical and technical reason of joining new and old GIS together, the test may be performed at reduced voltage level for an extended duration subject to agreement between SEC and supplier. V. Assessment of Tests

i. Test is considered passed if no disruptive discharge occurs during the test period. ii. If disruptive discharge occurs in solid insulation, the compartment should be opened and

repaired. After fault repair, again, test with full site test voltage. iii. If disruptive discharge occurs in gas, the test may be repeated and if discharge again

takes place, then compartment should be opened to clean out the compartment. iv. If the discharge occurs and second time it disappears, it should be considered acceptable

after repeating one test more at full site test voltage mentioned in Table 1. VI. Repetition of test after flash over at site Test may be repeated several times to listen and locate the location of fault point subject to the agreement between SEC and Contractor. Table-1 on the next page describes the exact test voltage levels, time and kind of tests to be applied after erection of GIS at site.

i. For 132 kV GIS the test voltage shall be 220 kV AC 60 Hz for one minute as per Procedure A clause 7.107.1.5 of IEC 517- 1990

ii. For 380 kV GIS and GIBs shall be 416 kV AC 60 Hz for one minute as per procedure A

clause 7.107.1.5 of IEC 517-1990. iii. In case of procedure B as per clause 7.107.1.5 of IEC 517-1990 the test voltage for 132

kV rated GIS shall be 84 kV AC for 5 minutes and followed by 416 kV Impulses of three positive and three negative polarities.

iv. In case of procedure B to be applied for high voltage tests on 132 kV GIS special VT

should be used as Test voltage source. GIS VTs shall not be used as HV test voltage source.

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Table 1. Test Voltage Levels for Metal-Enclosed Gas Filled Switchgear (GIS)

Met

hod

No.

Sys

tem

Rat

ed

Vol

tage

K

V

Ele

ctric

al

Con

ditio

ning

AC

Tes

t V

olta

ge

kV

Freq

. O

f Tes

t V

olta

ge

Tim

e O

f A

C T

est

Vol

tage

Sw

ing

or

Sw

itchi

ng.

Impu

lse

leve

l

No.

Of

Impu

lses

Par

tial

Dis

char

ge

Mea

sure

RE

MA

RK

S

A 13.8 10 kV for 10 min. 30 60 Hz 1 min. - - -

Leakage current < 1000

mA

A 33 22 kV for 15 min. 56 60 Hz 1 min. - - -

Leakage current < 0.86

mA

A 69 44 kV for 30 min. 128 60 Hz. or 10-

300 Hz. 1 min. - -

At 48 kV less than

10 pC

Electrical conditioni

ng is a cleaning process

only.

B 69 - 44 60 Hz. 5 min. 248 kV

3 positive

3 negative

A 110 84 kV for 30 min. 220 60 Hz. or 10-

300 Hz. 1 min. - -

At 92 kV less than

10 pC



only.

B 110 - 84 60 Hz. 5 min. 416 kV

3 positive

3 negative

A 115 84 kV for 30 min. 220 60 Hz. or 10-

300 Hz. 1 min. - -

At 92 kV less than

10 pC



only.

B 115 - 84 60 Hz. 5 min. 416 kV

3 positive

3 negative

A 132 84 kV for 30 min. 220 60 Hz. or 10-

300 Hz. 1 min. - -

At 92 kV less than

10 pC



only.

B 132 - 84 60 Hz. 5 min. 416 kV

3 positive

3 negative

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A 230 142 kV for 30 min.

316

10-300 Hz.

Better 60 Hz.

1 min. - - -

B 230 - 142

10-300 Hz.

Better at 60 Hz.

5 min. 608 kV

3 positive

3 negative

A 380 245 kV for 30 min. 416

10-300 Hz.

Better at 60 Hz.

1 min. 840 kV

3 positive

3 negative

PD or HF detection

techniques to be

applied

Impulse test is

applied in

special cases only

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3.12 Metal Clad Switchgear (Standard Reference is IEC 62271-100 and relevant SEC Transmission Specifications)



1. Inspect for physical damage or defects. 2. Check nameplate information for correctness. 3. Inspect enclosures for proper alignment, foundation fixing and

grounding and vermin proofing.

4. Inspect all covers, panels section and doors for paint work and proper fit.

5. Check for smooth and proper movement of racking mechanisms for alignment, shutters, rollers, rails and guides.

6. Check for proper alignment of the breaker primary and secondary contacts.

7. Check operation of all mechanical interlocks. 8. Check tightness of all bolted connections (torque wrench

method).

9. Check bus and supports for defects such as cracked welds, chipped porcelain, cracked insulation, etc., and free from dust accumulation.

10. Check main and riser buses for correct phasing. 11. Verify that all front panel mounted devices (meters, push

buttons, switches, indicator lamps, mimic buses, etc.) are installed as per drawings.

12. Perform mechanical checks and visual inspection on all circuit breakers.

13. Perform mechanical checks and visual inspection on all current transformers.

14. Perform mechanical checks and visual inspection on all voltage transformers.

15. Perform mechanical check and visual inspection on all disconnect and grounding switches.

16. Check for correct breaker position indication. 17. Check for correct spring status indication (spring

charged/discharged).

18. For air magnetic breakers check the arc chutes for damage and correct positioning above the interrupter contacts.

19. For minimum oil breakers, check correct oil level in each pole. 20. For SF6 breakers, check the correct gas pressure, quality and

leakage where possible.

21. For SF6 breakers, check the operation of the gas density switch (alarm and lockout functions).

22. Perform all specific checks on the breaker and spring operating mechanism according to the manufactures instructions.

23. Check that all control wiring is correct according to the approved drawing and terminal connections are secure.

24. Check all wiring is correct according to approved drawings. 25. Check that all phase marking have been installed per

specifications.

27. Verify that correct Dispatch Numbers have been installed.

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28. Check that all special tools, devices, etc., as per specification have been provided.



1. Insulation resistance test of all circuits in the panels. 500 V DC 2. Functional test of all controls and interlocks. 3. Bus continuity and phasing test. 4. Main Circuit Resistance Test with the switchgear erected but

not yet connected to the cables. Performed with 10 or 100 Ampere DC by micro-ohmmeter from panel to panel on each phase from cable spouts with all circuit breakers racked in service and in the on position.

The resistance values from panel to panel should vary no more than 15%. Compare the measured resistance values with factory test results, and shall be within +/- 20% of factory test results.

5. Check all AC/DC MCBS in the panel for correct ratings and grading. Trip test by current injection for one point on curve.

6. Insulation resistance test at 5 kV DC on all main circuits between phase to phase and phase to ground (before HV test).

7. Perform electrical tests on all component equipment as per SEC approved procedures:

a. Circuit breakers. b. Current transformers. c. Voltage transformers. d. Disconnect and grounding switches.

Ensure the cable spouts are included in the high voltage tests.

8. Insulation test on all wiring at 500 V DC. 9. Functional test of all electrical interlocks.

10. Functional test of trip free and anti pump circuits. 11. Functional test of local alarm and indications. 12. Functional test of remote alarm and indications. 13. Minimum control voltage trip and close operations. 14. Check and test capacitor trip circuit (if applicable). 15. Check spring charge time and motor currents at rated control

voltage.

16. Functional check of thermostat and space heaters, measure heater current.

17. Functional check of breaker operation counter. 18. Timing test open/close using an electronic oscillograph. 19. For SF6 breakers, verify electrically the low gas pressure alarm

and lockout functions.

20. For minimum oil breakers, test insulating oil for dielectric strength according to ASTM D 877 (with 2.5 mm gap).

21. Check correct operation of all auxiliary a and b contacts (for breaker open/closed position).

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Guidelines for High Voltage Tests on main circuits including CBs

i. Preparation and precautions before HV Test ii. For vacuum breakers, test across open contact and live parts to ground. Precautions

shall be taken against emission of X-rays. iii. For all other breakers. Test in conjunction with breaker racked in the switchgear and in

the closed position. The following shall be observed: New switchgear should be tested as a whole unit with all circuit breakers in the closed position

and not connected to cables. All back shutters must be closed. Gas circuit breaker interrupters should be checked to be within limits of correct pressure. VTs, cables or any other voltage indication should be disconnected and VTs secondary side

fuses should be removed. VTs, cables or any other voltage indication should be in out position and VTS secondary side

fuses should be taken out. CTs secondary terminals should be short-circuited and earthed. Test voltage should be applied on each phase to ground with other phases in earthed position.

The test should be repeated on other phases similarly. The test period should not be more than one minute at full test level and the test voltage

frequency should be kept at 60 Hz. Charging current for each test is noted and recorded. HV Test is considered successful if no breakdown occurs during test period. HV Test levels and time for pre-commissioning testing of switchgear are given in Table 2. II. AC High Voltage test The test program shall be: Voltage shall be applied on each phase with all other phases and then frame grounded. Tests shall be performed with the CB in both the closed and open position In the open position, the cable contacts are to be grounded. Test voltage levels are given in Table 2 below. After the high voltage test on main circuit is finished, rack the voltage transformers in service

position and apply a test voltage on the primary side equal to 1.5Un (Un = phase to neutral rated voltage) on each phase consecutively and measure the secondary output voltage same time during the test.

Make sure the VTs secondary side MCBs are switched off and any resistor in open delta winding should have been removed.

Compare the observed ratio with actual ratio. The HV Test should be repeated with circuit breakers in open position keeping cable spouts in

earthed condition in all panels.

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TABLE 2. TEST VOLTAGE LEVEL FOR MEDIUM VOLTAGE METALCLAD SWITCHGEAR

SWITCHGEAR RATINGS AC TEST VOLTAGE TIME PERIOD

11 kV 25 kV 60 Hz 60 Sec

13.8 kV 30 kV 60 Hz 60 Sec

33 and 34.5 kV 56 kV 60 Hz 60 Sec

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3.13 Metal Enclosed Bus Duct (Standard Reference is relevant SEC Transmission Specifications)



1. Inspect for physical damage or defects. 2. Check bus arrangement for conformance with approved

drawings.


4. Check that all enclosure grounding is securely connected. 5. Inspect internal compartments for cleanliness (free from dust

and moisture).

6. Check for watertight seals at joints including expanding interface points.

7. Check bus conductor support insulators for cracked insulation, chipped porcelain, etc.

8. Check quality of paint work (inside and outside). 9. Check that ventilation opening are not blocked, and meet

specified Degree of Protection.

10. Moisture drain holes available at bottom of enclosure. 11. Check anti-condensation heaters mounted at the correct

locations (bottom)



1. Perform phasing checks. Ensure correct phase identification. 2. Perform continuity check. 3. Bus joint resistance test. Ductor at 100 A DC 4. Insulation resistance test 5. HV test (to ground and between phases). 6. Heaters and thermostats functional test. Measure the heater

currents.

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3.14 Indoor and Outdoor Bus Structures (Standard Reference is relevant SEC Transmission Specifications)



1. Inspect bus and support insulators for physical damage or defects.

2. Check bus physical arrangement for conformance with approved drawings.

3. Check bus connections for correct phasing and marking of phases.


5. Check for proper phase to phase and phase to ground clearances.

6. Ensure that PT, etc., connections are flexible, to prevent transferring expansion stress from the bus



1. Measure resistance of bus section joints. Ductor at t 100 A DC. 2. Insulation resistance test at 5 kV DC. 3. HV test (indoor bus work including PTs where applicable, 69 kV

and below).

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3.15 Indoor Circuit Breakers (Standard Reference is relevant SEC Transmission Specifications)



1. Inspect bus for physical damage or defects. 2. Check nameplate information for correctness. 3. Check tightness of all bolted connections (torque wrench

method).

4. Check all wiring is correct according to approved drawings and that terminal connections are secure.

5. Check quality of paintwork. 6. Check that all grounding cables are securely connected. 7. Check breaker truck, rails, for proper alignment and smooth

movement.

8. Check operation of all mechanical interlocks with associated disconnects, grounding switches, racking truck mechanism, cubicle doors, etc.

9. Check for correct breaker position indication (breaker open/closed).

10. For minimum oil circuit breakers, check for correct oil level in each pole.

11. For SF6 breakers: a. Check for correct SF6 pressure in each pole. b. Check for gas leakage. c. Calibrate SF6 pressure gauge. d. Check operation of gas density switch (alarm and

lockout functions). e. Verify that all special filling adapters have been

provided.

12. For motor/spring operation mechanisms: a. Check manual spring charge operation. b. Verify correct spring status indication (spring

charged/discharged). c. Perform all specific checks on the mechanism

according to the manufactures instructions.

13. For pneumatic operating mechanisms(69KV and above): a. Check the compressor, air piping, valves, pressure

gauges, air filter, water trap and switches for damage, defects or blockage.

b. Calibrate the air pressure gauges. c. Check the setting of air pressure switches (compressor

start/stop, alarm, lockout). d. Perform all specific checks on the compressed air

system according to the manufacturers instructions. e. Check for correct direction of compressor rotation. f. Check air-charging time. g. Check safety relief valve operating pressure and

resetting pressure. h. Measure air consumption for C, O, CO and OCO

operations. i. Air storage test, perform as specified, the following

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without replenishment: 5X CO, or O + CO + 3min. + CO

j. Air leakage test (pressure drop method over 24 hours, CB closed and open).

14. For hydraulic operating mechanisms: a. Check, the pump, piping, valves, gauges and switches

for damage/defects/blockage. b. Bleed air from hydraulic system. c. Calibrate the fluid pressure gauges. d. Check the Nitrogen pre-c

Pre-Commissioning TestsProcedure for SEC Transmission Electrical Installation

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Transcript of Pre-Commissioning TestsProcedure for SEC Transmission Electrical Installation