Megger Testing of Busses Mccs and Distribution Panels Draft

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Subject: Megger Testing of Busses, MCCs, and Distribution Panels

Revision Number and Date: R 0 1/17/2011 Procedure No.: LUM-FFA-MNT-0016

Use: Reference

Effective Date: TBD

Prepared by: Jerry Wayne Date: ____________________

Reviewed by: Gwen Holladay_________________________________ Date: ____1/25/11______

Approved by: ___________________________________________________ Date: ____________________

Required review frequency: TBD

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Table of Contents1. Purpose and Scope........................................................................................................................................ 42. Acceptance Criteria...................................................................................................................................... 43. Special Tools and Materials....................................................................................................................... 4

3.1 Tools............................................................................................................................................................................. 43.2 Materials..................................................................................................................................................................... 4

4. Precautions, Limitations, and Notes.......................................................................................................54.1 Precautions................................................................................................................................................................54.2 Limitations.................................................................................................................................................................54.3 Notes.............................................................................................................................................................................5

5. Prerequisites.................................................................................................................................................. 65.1 Planner........................................................................................................................................................................ 65.2 Electricians................................................................................................................................................................ 6

6. Definitions and Acronyms.......................................................................................................................... 77. Instructions..................................................................................................................................................... 7

7.1 Busses / Motor Control Centers / Distribution Panels..........................................................................77.2 Loads............................................................................................................................................................................ 9

8. References.................................................................................................................................................. 1098.1 Development References..................................................................................................................................108.2 Performance References...................................................................................................................................10

9. Attachments.................................................................................................................................................. 10

Attachment A: Megger Test Data Sheet.........................................................................................................................11

List of TablesTable 1: Signature Box..............................................................................................................................................................7

Table 2: Test Voltages...............................................................................................................................................................8

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ReviewsWriter completes this section and deletes from final version after approval. Review comments are stored in <type location where comments are stored.>.

< In the Name column, list the names of reviewers you plan to review your document.>

Internal Review

Stakeholder Review

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1. Purpose and ScopeThe purpose of this procedure is to provide instructions for performing insulation resistance (megger) testing of busses, motor control centers (MCCs), and distribution panels. This procedure provides the minimum guidelines and acceptance criteria necessary to ensure that you perform meggering is performed in a safely and consistently manner.

2. Acceptance CriteriaThe following acceptance criteria must be met to complete the procedure.

The minimum acceptable value for insulation resistance (R min.) in megohms between phase-to-phase (busses and feeder cables) and phase-to-ground should equal or exceed one of the following values:

R min. should be equal to or greater than one megohm per KV of rated voltage of equipment plus one megohm.

The the minimum value specified by the equipment manufacturer if different from above, as specified on the applicable Work Order.

3. Special Tools and MaterialsUse the following special tools and materials to perform this procedure.

3.1 ToolsThe following special tools are required:

Statascope Statoscope (hot stick) (as required) Ground stick (as required) Ground straps/jumpers Class II Rrubber insulated gloves (600V or greater) with leather protectors Fire retardant coveralls Voltmeter Continuity checker Megger

DevDocs, 01/24/11,

A comma makes this easier to read--is it appropriate?

DevDocs, 01/25/11,

Is a statoscope interchangeable with a hot stick? "Hot stick" seems to be more commonly used online.

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3.2 MaterialsThe following special tools materials are required:

None

4. Precautions, Limitations, and NotesBefore performing the procedure, ensure you understand the following precautions, limitations, and notes.

4.1 Precautions The following precautions shall be followed:

To ensure the safety of personnel and accuracy of the test, Gground the test specimen to discharge the accumulated charges after application ofapplying megger potential., for the safety of personnel, as well as for test accuracy.

Grounding should be the test specimen for four times the amount of time you applied the test voltage was applied.

Observe electrical safety precautions to prevent personnel injuries or component damage when working on energized equipment.

Ensure that designed protection features are not defeated during performance of the work. Wear Class II rubber gloves and fire retardant coveralls when meggering at 1001 volts or

greater, including when connecting and disconnecting meggering equipment. Connect ground lead first, and then HV lead. Disconnect ground lead last. Ensure thatUse a good connection to earth ground is used for both meggering and discharge

of equipment under test. Warn and keep other personnel away from equipment during insulation testing and a

capacitance discharge. Utilize safety barriers and flagging when appropriate. Do not perform insulation test in a flammable or explosive atmosphere.

4.2 LimitationsNone

4.3 NotesThe following information may be used while performing the procedure:

DevDocs, 01/24/11,

Is "good" specific enough?

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Warning: Do not defeat designed protection features while performing the work.

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Or "after you apply"

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Do not record readings within the body of this procedure if you are meggering is being performed to obtain "Information Only" type data, as in case of trouble shooting.

Do not record readings here if you are meggering is being performed as part of another approved procedure.

Report discrepancies or unsatisfactory results to the Work Group Supervisor for follow-up actions. Record problems found in the "Remarks" section of work package.

Read the analog megger on the scale giving best resolution, and record. Use specific measurements rather than descriptions such as "greater than" or "less than." should not be used. Do not take mMegger readings should not be taken while the pointer or display is pegged (unless on the highest available range), erratic, or in transit.

Record the actual value displayed value on the digital megger, except that the word "Infinity", "INF" or the infinity symbol should be used when the display shows the digit "1" in the first (left hand) position with the other positions blank.

If an MCC drawout unit is removed, ensure the following:

o Visually inspect all contacts after the bucket has been slid into MCC, tightened down, and seated against the back of the cubicle.

o Check all draw out contacts for continuity which that have external power cables connected for continuity. They should be less than 10 ohms resistance.

o Inspect breaker stabs for signs of overheating by looking for discoloration or signs of arcing.

5. PrerequisitesThe following prerequisites must be met before performing this procedure.

5.1 PlannerThe planner must enter the following information:

Work Order No.: __________________________________ Component Tag No.: ______________________________ Unit No.: ____________________________________________ Serial No.: __________________________________________

5.2 ElectriciansPersonnel performing this procedure shall review all instructions, and safety requirements prior to performing this procedure.

DevDocs, 01/24/11,

on the Work Order? For each machine to be tested?

DevDocs, 01/24/11,

"have"? "display"?

DevDocs, 01/25/11,

1. "If you remove an MCC drawout unit" or If an MCC drawout unit has been removed"2. I included MCC in Sect. 6, Definitions and Acronyms.

DevDocs, 01/24/11,

unless the value displayed is "1" in the first (left-hand) position and the other positions are blank. In this case, record the value as "Infinity," "INF," or the infinity symbol.

DevDocs, 01/24/11,

Where? on the Megger Test Data Sheet?

DevDocs, 01/24/11,

"that is giving" or "that gives"?

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Is this the same as the Work Order on p. 4, section 2?

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"for example if you are"

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Each personAfter performing work using this procedure, is required to record their your name in the following signature box (see Table 1: Signature Box). If you do not have an RACF ID is unavailable, include your the contact information of the individual.

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In the table below, print name, sign name, and initials of the individuals performing this procedure.

Print Name Sign Name Initials RACF ID

Table 1: Signature Box

Enter following information on Attachment A: Megger Test Data Sheet:.

Equipment Rated Voltage Test Voltage M&TE numbers and Calibration Due Dates

6. Definitions and AcronymsCR (from bottom of page 9)

Live-Dead-Live (L-D-L)

Motor Control Centers (MCCs)

7. InstructionsThe procedures below contain instructions for the following tasks:

Busses / MCCs Motor Control Centers / Distribution Panels Loads

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What does this stand for?

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[7.1] Busses / Motor Control Centers / Distribution Panels

Note 1 Use this section to perform megger testing of load center busswork that has been isolated from all of its respective loads. Refer to Section 7.2 for megger testing of individual loads.

[1.] Ensure Switch power supply breaker to is in "Open" or "Off" position.

[2.] Use L-D-L method to de-energize Ensure load side connections of power supply breaker are de-energized by electrical measurements. Use L-D-L method.

[3.] Isolate Ensure all loads associated with buss to be tested. have been isolated.

[4.] Disconnect high high-voltage sensitive devices and potential transformers from buss to be tested.

[5.] Record and verify leads lifted, and fuses removed on Verification Sheet. Verify that information is correct, and have a Use second person man as verifyier the information.

1.[6.] Use table below for appropriate Test Voltages.

Bus Voltage Test Voltage DC480 500

2500 2500

4160 5000

6900 5000

13800 10000

2: Test Voltages

[7.] Megger busswork phase-to-phase then phase-to-ground for one minute, until readings are stable, or until acceptance criteria is reached.

[8.] Record readings on Attachment A: Megger Test Data Sheetthe Data Sheet.

2.[9.] Ground and discharge each phase tested.

3.[10.] Compare readings taken with the acceptance criteria given in Section 2.

DevDocs, 01/25/11,

Is it one minute each or one minute total?

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Should this be ?

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[11.] Remove all test leads and grounding devices. Record on Attachment A: Megger Test Data SheetMegger Test Data Sheet.

[12.] Connect high voltage sensitive devices, and potential transformers.

[13.] Record and verify leads landed and fuses installed on Attachment A: Megger Test Data SheetVerification Sheet. Have a Use second personman as verify the informationier.

4.[14.] Perform a post work close-out inspection to ensure that all tools and foreign material have been removed.

7.1[7.2] Loads

[Note 2] Megger testing is only required for power circuits. Megger testing instrument and control circuits is not required, or desirable.

1. Use applicable electrical drawings to determine what loads to megger test.

2. Record tag numbers and test connections for each load to be meggered on Attachment A: Megger Test Data Sheet.

[3.] Ensure Switch circuit breaker for each load tois in "Open" or "Off" position.

[4.] Use L-D-L method to de-energize Ensure load side connections of each breaker are de-energized by electrical measurements. Use L-D-L method.

3.[5.] For motors only, perform phase-to-phase continuity checks between each phase and record "Sat" or "Unsat" on Attachment A: Megger Test Data Sheet.

Note 2[Note 3] Phase-to-phase megger readings are only required for feeder cables to other MCCs or distribution panels. The breaker on the opposite end of the feeder cable must be open to obtain satisfactory readings.

[6.] Megger each load phase-to-ground and, only if required, phase-to-phase for each load for approximately one minute or until acceptance criteria is reached.

4.[7.] Ground and discharge each load tested.

5.[8.] Remove all test leads and grounding devices. Record on Attachment A: Megger Test Data Sheet.

DevDocs, 01/25/11,

"test results"?

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Does this need to be in boldface?

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6.[9.] Review all readings taken and determine if they meet acceptance criteria as given in Section 2.

7.[10.] Contact your supervisor and report any equipment deficiencies. Write a CR for repair or evaluation of the equipment.

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8. ReferencesDevelopment references are documents used to develop the procedure. Performance references are documents referenced within the procedure.

8.1 Development References[1] IEEE Std 43-2000 Recommended Practice for Testing Insulation Resistance of Rotating

Machinery[2] IEEE Std 62-1974 Guide for Field Testing Power Apparatus Insulation

8.2 Performance References[1] Generation Safety Handbook[[2]] LUM-FFA-REL-0014 Standard of Human Performance Improvement (LUM-FFA-REL-

0014)[[3]] LUM-FFA-SAF-0002 Hazardous Energy Control Program: LOTOV-Lockout/Tagout /Verify [[4]] (MSDS) Material Safety Data Sheet (MSDS)

9. Attachments The following attachments are appended to this procedure.

Attachment A: Megger Test Data Sheet

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No document number?

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Attachment A: Megger Test Data Sheet5.2 Equipment Rated Voltage: __________ VAC Test Voltage: ___________ VDC

7.1 Busses / Motor Control CentersMCCs / Distribution Panels

Equipment Tag Number: ___________________________

A-B ________ Megohms B-C ________ Megohms C-A ________ Megohms

A-G ________ Megohms B-G ________ Megohms C-G ________ Megohms

================================================================




================================================================




Acceptance Criteria: Equal to or greater than one megohms per KV of rated voltage in step 5.2 plus one megohm, or as specified on Work Order.

7.1.11 _________/_________________ Test leads and ground devices removed.

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Attachment Cont'd: Megger Test Data Sheet7.2 LOADS

Loads (Tag No.) Continuity (Motors Only) Test Connections Megohms

Acceptance Criteria: Equal to or greater than one megohms per KV of rated voltage in step 5.2 plus one megohm, or as specified on Work Order.

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7.2.8 _________/_________________ Test leads and ground devices removed.

Attachment Cont'd: Megger Test Data SheetRemarks: ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Test Personnel: ____________________________________________________________ Date: ______________________

Test Personnel: ____________________________________________________________ Date: ______________________

Data Reviewed and Approved: ___________________________________________ Date: ______________________Work Group Supervisor

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Revision HistoryRevision Number Approval Date Name Changes

R 0 TBD Jerry Wayne Initial Draft

R 0 TBD Gwen Holladay Edits

Megger Testing of Busses Mccs and Distribution Panels Draft

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