Testing & Commissioning Manual SEC

8/10/2019 Testing & Commissioning Manual SEC

1/125


2/125

1.0 INTRODUCTION

Proper pre-commissioning of new electrical equipment is important to prove that new equipment hasbeen properly shipped and correctly erected and installed. This Procedure highlights the necessary stepsrelated 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-commissioningtesting 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 workat site during the pre-commissioning test period.

1.1.2 To provide the minimum tests to be performed on the equipment by thecontractor, 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 beperformed 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

TRANSMISSION

PRE-COMMISSIONING TEST PROCEDURE

Index Number:

T-PreCom-1000-R0Revision Number:

00Prepared By:

Pre-Commissioning Committee

Original Issue Date:

2003-06-17Revised By: Revision Date:

Recommended By:

Mohammad S. AL-RafaaPage Number:

1 of 124

Title:

PRE-COMMISSIONING TESTPROCEDURES FOR SEC

TRANSMISSIONELECTRICAL INSTALLATIONS

Approved By:

I.Y. Al-Hamoudi, Vice President CTA
http://c/Documents%20and%20Settings/11839/Local%20Settings/Temp/precomissioning%20test%20procedures29-03-2004%20rev%20040330.doc


3/125

TRANSMISSION

PRE-COMMISSIONING TEST PROCEDUREPART I

Title:

PART I: ORGANIZATION OF THE WORK

Index Number:T-PreCom-1000-R0

ATSITE 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 witnessedby SEC Commissioning engineer or technician. During the course of the commissioning it has beenobserved that at many stages the contractors are not ready and consequently the Commissioningpersonnel have to wait with the result that some tests may be missed or ignored. A procedure is requiredto check the complete readiness of the contractor before the pre-commissioning tests and prepare thecommissioning engineer/technician for applying commissioning tests as per SEC commissioningProcedure. This document briefly outline the necessary steps to be followed to ensure that contractorsare ready to start the pre -commissioning in order to reduce or maintain the approved project milestonesand control the quality of the commissioning test.

The main purpose of this procedure is to provide necessary guidelines to ensure the readiness of thecontractors to start the pre-commissioning testing of new or reinforcement projects and how to apply andperform 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 jointinspection shall be conducted with commissioning personnel and the contractor to ensure thecontractors readiness to start the project after written confirmation is received from ProjectManagement.

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 ProjectQuality 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 followingpoints shall be confirmed.


4/125

TRANSMISSION


Title:





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, PCand PC table.

Conference room with conference table, chairs, white board, telephoneand notice board.

Drawing/record room with filling cabinets and Operation andMaintenance 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 relevantspecifications 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 FileThe Commissioning engineer/technician shall have a Commissioning File for each substation; theFile 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 RectificationsCommissioning personnel are responsible for witnessing the pre-commissioning tests forreinforcement and new substations. During the course of witnessing, the necessary SiteInstructions (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 particularpoint. Therefore guidelines are required for issuing S.I.s. This document briefly describes the


5/125

TRANSMISSION


Title:





guidelines to be followed by all Commissioning personnel to issue S.I.s in order to achieveuniformity and consistency. It should be kept in mind that this is a guideline only and it will notsupercede 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 thedeficiency 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 helpan engineer to visualize the project and the other section for the deficiencies. After one weekfrom 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 listhas to be issued by the contractor on the SEC format, Attachment No. 4. One month prior to thescheduled energizing of the equipment, the categorized deficiency list shall be issued by thecommissioning personnel to identify the items which must be corrected prior to energization(Attachment No. 5).

ATTACHMENTS TABLE

ATTACHMENTNO.

DESCRIPTION REMARKS

1. RegisterBook/DeficiencyRecord

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

2. Register Book/ActivityRecord

The Commissioning engineer/technician is responsible to dailyupdate site activities to help any engineer to familiarize himwith 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 theSite Instructions Form.

4. Status of the PunchList

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

5. Categorization of thePunch List

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

6. Pre-CommissioningTime Utilization

Statistic Sheet

The commissioning engineer/technician shall fill in this sheet ona 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(OptionalAgreement)

In order to reduce the pre-Commissioning time the samplecheck procedure may be exercised based on the contractorsprevious performance and the last time utilizations statussheet. This shall be based on agreement between thecontractor and SEC Transmission.

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

10. ContractorsPerformance Report The commissioning engineer/technician shall fill this form at theend of the project to evaluate the performance of thecontractor.
http://check%20list19-9.pdf/http://check%20list19-9.pdf/


6/125

TRANSMISSION


Title:





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 withan 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 thecommissioning 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 therespective substation file for implementation at a later stage. Such items shall be communicated toEngineering and Design Department for inclusion in future Projects.

The contents of the S.I. can be categorized under various headings as noted below. The commonSnags/Punch list mentioned will be issued once in one S.I. for the whole substation and repetition of thesame 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 Protectionrequirements.

Work has not been executed in line with general requirements or has not had approvalduring the design stage.

Design comments have not been implemented for the protection scheme and otherequipment.

4.3 Poor Work Quality


Segregation of protection CT and VT cables is not maintained and color coded cables arenot used.

Poor ferrule printing quality which will fade over time.


7/125

TRANSMISSION


Title:





Cables are directly terminated on terminal blocks without providing adequate clearancesfor 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, andacknowledge/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 frontof 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 andserious 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 relevantspecification. 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 tooperate.

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


Equipment is missing from the apparatus list.


8/125

TRANSMISSION


Title:





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 areclearly mentioned in the SEC Specifications/General Requirements. Irrespective of this fact, theyare usually repeatedly discovered. When these types of points are raised at site, the contractorgenerally tries to avoid implementation. Every effort should be made to have the contractorpromptly correct the inadequacies. Some examples are listed as follows:

Color-coded cables shall be used for control and/or alarm functions and black ones shallbe 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 isrequired.

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

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

Equipment lists do not correlate with the installed equipment and details such as orderingnumber 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 arrangementsincluding 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, powertransformer marshalling kiosks, CB isolators and earth switches, etc. This equipmentincludes 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 otherspecific 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.


9/125

TRANSMISSION


Title:





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

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 wascontrolled by the first main DC supply.

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

Protection coordination of MCBs installed in the DC distribution board was notmaintained, 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 withSEC specifications.

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

Remote end breakers also trip in case the HV E/F relay of transformer operates. Itshould 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 thetripping 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 sparefeeder led to operation of BBP.

The anti pumping circuit is not operational for CBs. This deficiency will lead to re-closingof 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 toindiscriminate tripping.

The DEF relay for one circuit is commissioned with wrong direction this will lead toindiscriminate 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, relaypanels, 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.


10/125

TRANSMISSION


Title:





Labeling of relays, pressure relief devices, oil temperature gauges and windingtemperature 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 theirimplementation. Sometimes it is very difficult to confirm their implementation once the substationis energized, if they are not cleared during the pre-commissioning stage. It is very useful that thewitnessing engineer/technician keeps the site instruction records updated by putting his signaturewith 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 donewith optimal use of the time available.

5.1 Check List

The Check List is intended to provide information to commissioning personnel who are assignedto inspect the contractors work and witness commissioning testing on behalf of SEC to verify thatsubstation and transmission line equipment and system are acceptable as per SEC- Standardsand 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 indaily. The contents of this sheet will be used for planning future projects by using the total timeconsumed. 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 SECthe testing schedule, giving details for each test of the time and the commissioning personnelrequired. Every week, the contractor shall submit a three-week testing program giving details of theprevious weeks completed jobs and the current and following weeks proposed jobs. If in theprevious week, some job was not completed, a reason for the deferral and its effect on the overallschedule 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-builtdrawings 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


11/125

TRANSMISSION


Title:





5.5 Sample Check (Optional)

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

If the overall rating of the contractor performance in his immediately previous contractwas GOOD.

If the hours lost due to the contractor is less than 5% of the work, for the last timeutilization 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 thecommissioning engineer/technician (Attachment No. 7). In case of separate contractors working on thesame substation (lines and substation), the line-commissioning engineer/technician shall provide a copyof the final reports to the substation-commissioning engineer/technician and vise versa. Eachcommissioning engineer/technician shall evaluate the contractor at the end of the project, see AttachmentNo. 10.

6.1 Final Pre-Commissioning Report

The commissioning engineer/technician shall issue the Report based on but not limited to thefollowing.

The status of the Punch List (A, B) for which A refers to any deficiency requiring anoutage to clear it or equipment damage or a safety requirements. B is any deficiencyother 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 thefollowing criteria:

Quality of the work. Availability of qualified manpower. Availability of proper tools and test equipment. Quality of supervision/testing engineer. Safety.

Cooperation. Punctuality.


12/125


13/125

TRANSMISSION


PART IITitle:

MECHANICAL CHECKS, VISUAL INSPECTIONS


AND ELECTRICAL TESTSPage Number:

Page 12 of 124

1.0 INTRODUCTION

This Procedure describes the tests and checks to be performed during the pre-commissioning stage ofSEC Transmission projects. It deals primarily with the pre-commissioning tests to be followed forprotection schemes and main equipment such as cables, transformers and switchgear, etc., keeping inview the SEC standard practices for various types of tests. Further, this listing of tests and checks isbased 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 ontransmission equipment. They shall be performed by the project contractor and witnessed by SECPrecommissioning 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 Transformers3.6 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 Control3.31 Substation Batteries

3.32 Battery Chargers

3.33 AC Distribution Panels

3.34 DC Distribution Panels


14/125

TRANSMISSION


PART IITitle:




Page 13 of 124

3.35 LVAC Auto-Transfer Schemes/Switches

3.36 Grounding Systems

3.37 Switchgear Air Compressor Systems 3.38 HVAC Systems

3.39 Dry Transformers

3.40 Fire Detection and Suppression Systems4.41 Civil Work

4.42 Static VAR Compensation Systems


15/125

TRANSMISSION


PART IITitle:




Page 14 of 124

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 duringtransit.

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 groundingconnections 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 areopen.

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

11. Check for correct color and quantity of desiccant (moistureabsorbing media) in breathers. Check for correct breather oillevels.

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

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

14. Check all pipes, hoses and fan protection (not rubber or plastic).

15. Check the vertical and horizontal clearances of live parts toadjacent 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 Devicemicroswitch.Push buttons and indicators.Oil sampling port (main tank and OLTC).Upper and lower main tank valves.

Tap changer diverter switch compartment, oil filteringpumps and filter in good condition (if available).

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

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


16/125


17/125

TRANSMISSION


PART IITitle:




Page 16 of 124

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

tap changing. This should be done during the windingresistance 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 pointsbelow 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 onCT 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 oiltest reports tested at an independent laboratory, for thefollowing:

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

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

tankb. 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 theirown analysis and comparison purposes. A syringe oil sampleshall be taken by contractor.

19. A main tank insulation oil sample for dissolved gas analysisshall be taken immediately prior to first energizing a powertransformer and another sample three days after continuousenergization.


18/125

TRANSMISSION


PART IITitle:




Page 17 of 124

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



1. Check the impact recorder for any abnormal impact duringtransit.

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 groundingconnections 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 areopen.

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 oillevel.

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

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

14. Check all pipes, hoses and fan protection (not rubber or plastic).

15. Check the vertical and horizontal clearances of live parts toadjacent 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 pressurefor 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.


19/125

TRANSMISSION


PART IITitle:




Page 18 of 124

3.2.2 Electrical Tests


1. Core Insulation Resistance Test

2. Winding Insulation Resistance Measurement Test andPolarization 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 oilbath and checking against standard thermometer. Also checkby current injection. Setting as per approved drawing to beapplied 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 pointsbelow 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 onCT 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 oiltest reports tested at an independent laboratory, for thefollowing:

a. Dielectric Strengthi. ASTM D 877 (2.5 mm gap) for unprocessed oilii. ASTM D 1816 (1.0 mm gap) for oil in main

tankb. 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 theirown analysis and comparison purposes. A syringe oil sample


20/125

TRANSMISSION


PART IITitle:




Page 19 of 124

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 flowdirection.


21/125


22/125

TRANSMISSION


PART IITitle:




Page 21 of 124

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 wrenchmethod).

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 SECsspecifications.

6. Check that impulse counter and leakage current meter glassesare 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.


23/125

TRANSMISSION


PART IITitle:




Page 22 of 124

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 duringtransit (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 orHV fuses.

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



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 barphasing in the distribution panels and with the main transformerphases.

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 voltagetap.

12. Perform functional tests of all auxiliary devices (as applicable )

13. Insulating Oil Tests:Prior to energization, the contractor should submit insulating oiltest reports tested at an independent laboratory, for thefollowing:

a. Dielectric Strengthi. ASTM D 877 (2.5 mm gap) for unprocessed oilii. ASTM D 1816 (1.0 mm gap) for oil in main

tankb. 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).


24/125

TRANSMISSION


PART IITitle:




Page 23 of 124

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


25/125

TRANSMISSION


PART IITitle:




Page 24 of 124

3.6 Neutral Earthing Resistors(Standard Reference is Manufacturers Instructions)


1. Check the value of resistance and current ratings againstspecifications.

2. Check that the external earth connection to main earth is copperwire at least 240 mm

2in 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 toenergization.

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


26/125

TRANSMISSION


PART IITitle:




Page 25 of 124

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 relatingto the equipment into which they are installed.




2. Check nameplate information for correctness.

3. Check that outdoor secondary wiring terminations are installedin moisture proof enclosures.


5. Check that all grounding cables are securely connected.

6. Check secondary wiring is correctly color coded and size ofwires is as specified.

7. Check proper lugs have been used on terminations.

8. Check CT locations physically and secondary terminal labelinghas 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 kneepoint).

6. Loop resistance measurement test (burden test).

7. Phase identification test.

8. Verify secondary circuits, terminals, shorting/isolating links byprimary injection of CTs.

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

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

11. Test intercore coupling for all bus differential CTs.

12. Demagnetize CT cores after all tests.


27/125

TRANSMISSION


PART IITitle:




Page 26 of 124

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





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 allisolation 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.




2. Insulation resistance tests HV TO G, LV TO G and HV TO LVusing a one kV insulation tester.

3. Ratio Test.

4. Polarity Test.

5. Primary and secondary fuses rating checks for 11 kV VTs andabove (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 minuteFor electromagnetic VTs, seeTable 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 correctnessand 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.


28/125

TRANSMISSION


PART IITitle:




Page 27 of 124

TABLE 1

SYSTEM RATEDVOLTAGE (KV)

RATED LOADFACTOR

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 199380 1.5 329

60 Hz I Minute

These tests areapplicable to

electromagneticVTs


29/125

TRANSMISSION


PART IITitle:




Page 28 of 124

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





3. Check tightness of all bolted connections.


5. Check mechanical clearances and proper operation of allisolation 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 (ifapplicable).

9. Check drain coils (if applicable).





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.


11. Check on fast damping device (FDD).


30/125

TRANSMISSION


PART IITitle:




Page 29 of 124

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





3. Check tightness of all bolted connections.


5. Check mechanical clearances and proper operation of allisolating, grounding and shorting devices (as applicable).

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

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

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



1. Winding resistance test


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.


10. Perform all specific tests per manufacturers instruction

11. Phase angle check if the equipment is assembled at site.


31/125

TRANSMISSION


PART IITitle:




Page 30 of 124

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





3. Inspect enclosures for proper alignment and foundation fixingand 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 correctlyand that special filling and degassing fittings are provided andhave proper storage.

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

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

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

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

11. Check operation of all mechanical interlocks.


13. Check each gas section filled to correct rated pressure.

14. Check SF6gas at each gas section for air and moisture contentafter filling at rated pressure.

Permissible Dew Point is -35 Cor lower.

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

16. Calibrate gas pressure (density) gauges. Check the gaugeshave 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 orconfirm the correctness of all modifications.

20. Verify that all front panel mounted devices (meters, pushbuttons, switches, indicator lamps, mimic buses, etc.) areinstalled as per drawings, fixed permanently and are correctlylabeled.

21. Verify that all operating devices are correctly labeled.

22. Perform mechanical checks and visual inspections on allcomponent 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 beeninstalled as per specifications.


32/125

TRANSMISSION


PART IITitle:




Page 31 of 124

24. Ensure that all disconnect switches are provided with viewingwindows or mechanical indicators for verification of contactpositions and that all grounding switch positions can be visuallyverified.

25. Verify that correct Dispatch Numbers have been installed.

27. Check the closed barriers at the ends of each gas zones areexternally colored yellow or orange. The zone gas densitygauges shall have a zone marking plates fixed over the gauges.

28. Check GIS over pressure relief discs are not cracked ordeformed.



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

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

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

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

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

10. GIS PTs to be included during AC HV tests on GIS when testfrequency is well above rated frequency, otherwise test at 1.5Un one minute at rated frequency without secondary load. PTsecondary output volts shall be monitored during the highvoltage 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 itsmonitoring system locally as well as on mimic diagram in controlroom. Check VT HV neutrals externally available especially incase of VTS installed directly on cable feeder.

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

14. Verify the alarms being initiated by SF6density gauges on LCCand up to control room during calibration process.

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

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

Circuit breakers.Current transformers.Voltage transformers.


33/125

TRANSMISSION


PART IITitle:




Page 32 of 124

Disconnect and grounding switches.

17. Perform high voltage test at 10 kV AC for 1 minute on allgrounding 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 closedposition at 80% of the factory routine test voltage for one minute. Partial discharge measurements (Ifapplicable 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 erectionat 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 measuredin this case at test voltage level = 1.2 Un(Un= phase to neutral rated voltage) during theHV Test process.

Electrical conditioning at voltage equal to U/3 for longer period such as 30 minutes may beperformed 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 testat 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


34/125

TRANSMISSION


PART IITitle:




Page 33 of 124

In case the GIS VTs are not suitable to be used as test transformer; a special voltagetransformer shall be used to perform such tests. GIS VT can only be used as a testtransformer if the manufacturer guarantees its safety and capability to perform such testsotherwise 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 agreementbetween 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 aftererection of GIS at site.

i. For 132 kV GIS the test voltage shall be 220 kV AC 60 Hz for one minute as perProcedure 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 Aclause 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 132kV 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 VTshould be used as Test voltage source. GIS VTs shall not be used as HV test voltagesource.


35/125

TRANSMISSION


PART IITitle:




Page 34 of 124

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

Method

No.

SystemR

ated

Voltage

KV

Electrical

Conditioning

AC

Test

Voltage

kV

Freq.

OfTest

Voltage

TimeOf

AC

Test

Voltage

Swingor

Switching.

Impulselevel

No.

Of

Impulses

Partial

Discharge

Measure

REMARKS

A 13.810 kV for 10

min.

30 60 Hz 1 min. - - -

Leakagecurrent

< 1000mA

A 3322 kV for 15

min.56 60 Hz 1 min. - - -

Leakagecurrent< 0.86

mA

A 6944 kV for 30

min.128

60 Hz.or 10-

300 Hz.1 min. - -

At 48 kVless than

10 pC

Electricalconditioni

ng is acleaningprocess

only.

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

3positive

3negative

A 11084 kV for 30

min.220

60 Hz.or 10-

300 Hz.1 min. - -

At 92 kVless than

10 pC



only.

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

3positive

3negative

A 11584 kV for 30

min.220

60 Hz.or 10-

300 Hz.1 min. - -

At 92 kVless than

10 pC

Electrical

conditioning is acleaningprocess

only.

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

3positive

3negative

A 13284 kV for 30

min.220

60 Hz.or 10-

300 Hz.1 min. - -

At 92 kVless than

10 pC



only.

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

3positive

3negative


36/125

TRANSMISSION


PART IITitle:




Page 35 of 124

A 230142 kVfor 30min.

316

10-300Hz.

Better60 Hz.

1 min. - - -

B 230 - 142

10-300Hz.

Better at60 Hz.

5 min. 608 kV

3positive

3negative

A 380245 kV

for 30 min. 416

10-300Hz.

Better at60 Hz.

1 min. 840 kV

3positive

3negative

PD or HFdetection

techniquesto be

applied

Impulsetest is

applied

inspecialcasesonly


37/125

TRANSMISSION


PART IITitle:




Page 36 of 124

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





3. Inspect enclosures for proper alignment, foundation fixing andgrounding and vermin proofing.

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

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

6. Check for proper alignment of the breaker primary andsecondary contacts.

7. Check operation of all mechanical interlocks.


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

10. Check main and riser buses for correct phasing.11. Verify that all front panel mounted devices (meters, pushbuttons, switches, indicator lamps, mimic buses, etc.) areinstalled as per drawings.

12. Perform mechanical checks and visual inspection on all circuitbreakers.

13. Perform mechanical checks and visual inspection on all currenttransformers.

14. Perform mechanical checks and visual inspection on all voltagetransformers.

15. Perform mechanical check and visual inspection on alldisconnect and grounding switches.

16. Check for correct breaker position indication.

17. Check for correct spring status indication (springcharged/discharged).

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

19. For minimum oil breakers, check correct oil level in each pole.

20. For SF6breakers, check the correct gas pressure, quality andleakage where possible.

21. For SF6breakers, check the operation of the gas density switch(alarm and lockout functions).

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

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

24. Check all wiring is correct according to approved drawings.

25. Check that all phase marking have been installed perspecifications.



38/125

TRANSMISSION


PART IITitle:




Page 37 of 124

28. Check that all special tools, devices, etc., as per specificationhave 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 butnot yet connected to the cables. Performed with 10 or 100Ampere DC by micro-ohmmeter from panel to panel on eachphase from cable spouts with all circuit breakers racked inservice and in the on position.

The resistance values from panelto panel should vary no morethan 15%. Compare themeasured resistance values withfactory test results, and shall bewithin +/- 20% of factory testresults.

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

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

7. Perform electrical tests on all component equipment as per SECapproved 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 controlvoltage.

16. Functional check of thermostat and space heaters, measureheater current.

17. Functional check of breaker operation counter.

18. Timing test open/close using an electronic oscillograph.

19. For SF6breakers, verify electrically the low gas pressure alarmand lockout functions.

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

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


39/125

TRANSMISSION


PART IITitle:




Page 38 of 124

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. Precautionsshall be taken against emission of X-rays.

iii. For all other breakers. Test in conjunction with breaker racked in the switchgear and inthe closed position.

The following shall be observed:

New switchgear should be tested as a whole unit with all circuit breakers in the closed positionand 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 sidefuses 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 voltagefrequency 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 serviceposition and apply a test voltage on the primary side equal to 1.5U n(Un= phase to neutral ratedvoltage) on each phase consecutively and measure the secondary output voltage same timeduring the test.

Make sure the VTs secondary side MCBs are switched off and any resistor in open delta windingshould 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.


40/125

TRANSMISSION


PART IITitle:




Page 39 of 124

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


41/125

TRANSMISSION


PART IITitle:




Page 40 of 124

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




2. Check bus arrangement for conformance with approveddrawings.

3. Check tightness of all bolted connections (torque wrench

method).4. Check that all enclosure grounding is securely connected.

5. Inspect internal compartments for cleanliness (free from dustand moisture).

6. Check for watertight seals at joints including expandinginterface 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 meetspecified Degree of Protection.

10. Moisture drain holes available at bottom of enclosure.

11. Check anti-condensation heaters mounted at the correctlocations (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 heatercurrents.


42/125

TRANSMISSION


PART IITitle:




Page 41 of 124

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



1. Inspect bus and support insulators for physical damage ordefects.

2. Check bus physical arrangement for conformance withapproved drawings.

3. Check bus connections for correct phasing and marking ofphases.


5. Check for proper phase to phase and phase to groundclearances.

6. Ensure that PT, etc., connections are flexible, to preventtransferring 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 kVand below).


43/125

TRANSMISSION


PART IITitle:




Page 42 of 124

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



1. Inspect bus for physical damage or defects.



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

5. Check quality of paintwork.


7. Check breaker truck, rails, for proper alignment and smoothmovement.

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

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

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

each pole.11. For SF6breakers:a. Check for correct SF6pressure in each pole.b. Check for gas leakage.c. Calibrate SF6pressure 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 mechanismaccording 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 andresetting pressure.

h. Measure air consumption for C, O, CO and OCOoperations.

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


44/125

TRANSMISSION


PART IITitle:




Page 43 of 124

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-charge pressure in

accumulators.

e. Check for correct hydraulic fluid level in the reservoir.f. Check the setting of air pressure switches (pump

start/stop, alarm, lockout).g. Perform all specific checks on the hydraulic system

according to the manufacturers instructions.h. Check for oil leaksi. Check pump-up time.j. Check safety relief valve operating and resetting

pressure.k. Measure pressure drop for C, O, CO and OCO

operations.l. Stored energy test perform O + CO + 3min + CO

without replenishment.

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

n. Check operation of the nitrogen low pressure switch.




1. Measure resistance of main conducting circuits at 100 A DC.

2. Insulation resistance test of each breaker pole at 5 kV DC.

3. Insulation resistance test of all low voltage wiring and cabling.

4. Functional test of all electrical interlocks.

5. Functional check of trip free and anti pump circuits.6. Functional check of phase disagreement protection circuit

(applicable to breakers whose poles are not mechanically gangoperated).

7. Functional check of local control, alarm and indications.

8. Functional check of remote control, alarm and indications.

9. Minimum control voltage trip and close operation.

10. Functional check of breaker operation counter.

11. Functional check of thermostat and space heaters, andmeasurement of heater current.

12. Check correct operation of all auxiliary a and b contacts (forbreaker open/closed positions).

13. Timing test using an electronic oscillograph.

14. For SF6breakers, verify electrically the low gas pressure alarmand lockout functions.

15. For minimum oil circuit breakers, test insulating oil for dielectricstrength.

ASTM D 877(with 2.5 mm gap)


45/125

TRANSMISSION


PART IITitle:




Page 44 of 124

16. For motor/spring operating mechanisms, measure springcharge time and motor current.

17. For pneumatic or hydraulic mechanisms:a. Measure compressor/pump motor starting and running

currents.b. Verify electrically the low stored energy (fluid pressure)

alarm and lockout functions.c. Functional check of the motor excessive running alarm

circuit.

18. Verify the electrical operation of the breaker racking truck.Check the correct functioning of interlocks and limit switches.


46/125

TRANSMISSION


PART IITitle:


Index Number:T-PreC

Testing & Commissioning Manual SEC

Documents

Transcript of Testing & Commissioning Manual SEC