Preventive Maintenance/ Electric Service EquipmentBy Neil LaBrake, Jr., PE, National Grid, Syracuse, NY, November 10, 2009 at Turning Stone Resort

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Acknowledgements

Neil F. LaBrake, Jr., P.E. - Customer Facilities Engineer

National Grid

Chuck Mello, S.E.T. – Field Evaluation Program Manager

Underwriters Laboratories Inc.

Timothy M. Croushore, P.E. - Product Manager

Allegheny Power

Thomas L. Adams, P.E. - Commercial Consultant

Exelon Corp.

Barry N. Hornberger, P.E. - Sr. Engineer, New Business

PECO Energy Co. an Exelon Company

Richard Maybury, P.E. – founder and President

HMT Inc.

John Pertgen – Project Engineer

HMT Inc.

William Sieling, P.E. – President

Principle Engineering

NFPA; IEEE; NETA; OSHA; EEI; UL; IAEI

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The information presented and its accompanying classroom instruction reflect what is considered good practice with regard to safety, operation, and maintenance of electrical substations.

It is not intended to act as a substitute for an electrical safety program or to bring your facility into compliance with OSHA or other regulations or act as a substitute for expert advise from the manufacturer of your equipment. The responsibility for developing a safety program, insuring compliance with OSHA and other regulations, and the operation and maintenance of equipment ultimately rests with the owner/operator of the facility.

This Information Seminar should not be considered as official instruction or training in the area of high voltage safety. Attendees are not “certified” or “qualified” to work on or around energized equipment.

Through this Information Seminar, the utility representatives are simply sharing their utility’s typical practices in an effort to raise customer awareness of high voltage issues. Your organization’s Safety Department and the manufacturer of your equipment are the best source for specific high voltage information.

DisclaimerDisclaimer

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Electric Service Connection

which includes the service lateral, service entrance conductors, meter provision, service equipment, and grounding

NESC applicable

NEC applicable

NESC applicable for equipment under

exclusive control by utility

Where the Electric Utility has Mutual Interest

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Electrical Preventive Maintenance - EPM

Key Factor to High Reliability

Total 16.4% 20.8% 15.8% 30.6% 11.1%

*Small sample size; less than 7 failures caused by inadequate maintenance. Table 44, IEEE Std 493-1990

Percentage of Failure Caused from Inadequate Maintenance Versus Months Since Maintained

Failure (months since maintained)

All Electrical Equipment Classes

CombinedCircuit

Breakers Motors

*22.2% *2.6%

Less than 12 months ago 7.4% *12.5% 8.8%

Open Wire

Trans- formers

*0 *2.9%

38.2% 36.4%

12-24 months ago 11.2%

More than 24 months ago 36.7% 77.8% 44.4%

19.2% 8.8%

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The Bottom Line of EPM

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REFERENCES for MAINTENANCE SCHEDULE REFERENCES for MAINTENANCE SCHEDULE

Manufacturer Instruction Manuals Refer to Station Single Line Diagram Applicable Local Rules (

http://www.nationalgridus.com/electricalspecifications) NFPA 70B (http://www.nfpa.org/) NETA MTS (http://www.netaworld.org/)

For Main Service, Keep Serving Utility Informed of Electrical Problems and Planned Changes.

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Personnel Safety

NFPA 70E

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Station Inspection Sheets

Inspections performed at least once a day or week.

Suggested Items: Transformers - temp, oil level, pressure, explosion relief, fans,

bushing & paint condition.

Breakers - oil level, counter readings, bushings.

Switches - glass, jaws, blades & connections.

Batteries - sp. gravity, temp,voltage, amps, grounds.

Yard - debris, weeds, fence & danger signs.

Check for unusual smells or sounds

Check for Clearance of Foreign Material

Watch for Water

Pipes & Drains

Rain runoff

Check Enclosures and Locks to Restrict Access

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Some Considerations for Electrical Inspection

ELECTRIC SERVICE ACCEPTANCE SURVEY CHECKLIST

FOR USER-OWNED STATIONS - MEDIUM AND HIGH VOLTAGE

(reference: National Electrical Safety Code)

B. STATION: 1. Surfacing 2. Lightning Masts 3. Fence and Gates 4. Locking provisions on

gates & main disconnect 5. Accessibility 6. Danger Signs 7. Customer has operating equipment,

personnel & Maintenance/Test procedures

A. CLEARANCES: 1. Phase-to-Phase 2. Phase-to-Ground 3. Vertical 4. Safety 5. Working space

See Parts 1 and 2 in the NESC

See Part 1 in the NESC

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ELECTRIC SERVICE ACCEPTANCE SURVEY CHECKLIST – cont’d

C. SERVICE: 1. Main Disconnect Switch 2. Protective Equipment __Fuses __Ckt. Breaker __HV Fault Interrupter 3. Surge Protection 4. Insulators and connections 5. Power Transformer(s) - N.P. Data 6. Control circuits and battery system functional 7. Protective Relays - Settings issued & devices calibrated & functionally tested D. GROUNDING: 1. Ground Grid Resistance Test 2. Station Equipment and Fence 3. Main Disc. Switch Handle and Potential Equalizing Grid

See Part 1 in the NESC

See Section 9 in the NESC

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ELECTRIC SERVICE ACCEPTANCE SURVEY CHECKLIST – cont’d

F. METERING: 1. V.T.’s and C.T.’s 2. Secondary Conduit 3. Meter Panel G. OTHER: 1. Final set of drawings & nameplate info. 2. Transformer Test Report 3. Switching Operating Procedure (see Part 4 of the NESC) 4. Generator Characteristics Data (applicable to parallel generation projects)

See Part 1 in the NESCand

local utility requirements

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NFPA 70B

Figure F.8

Typical Electrical Switchgear – Associated Equipment Inspection Record

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NFPA 70B

Figure F.17

Typical Transformer - Liquid Filled - Inspection Record

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NFPA 70B

Fig. F.21

Typical Battery Tests

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NFPA 70B

Annex I

Recommended Maintenance Intervals

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ESB 755 O&M Requirements – PSC 220 Rule 4.1

4.1 Company is not responsible for the adequacy or safety of customer's equipment or wiring. Company reserves the right to discontinue service whenever customer fails to maintain such equipment and wiring in a safe and adequate condition or fails to utilize electricity in such a manner as to avoid interference with the service furnished by Company to other customers, or with the use of service by customer or others.

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ESB 755 O&M Requirements – PSC 220 Rule 14.3

14.3 In addition to the provisions of the Service Classifications as to the term of their respective Agreements for Service, the Company reserves the right to withhold service or to discontinue service or terminate any agreement therefore, in such manner as may be permitted by law under the circumstances, if the customer at any time refuses or fails to make application and Agreement for Service as provided by this schedule or defaults in the payment of a bill rendered for service, or if the customer refuses or fails to comply with any applicable provision, rule, regulation, term or condition of this schedule, or with any applicable law or order of the Public Service Commission or other authorities having jurisdiction, or if the customer's installation or part thereof is deemed by the Company to be unsafe, inadequate or unsuitable for receiving the Company's service, or to interfere with or impair the continuity or quality of the Company's service to the customer or to others, or if changes at customer's premises cause Company's facilities to become unsafe, inadequate or unsuitable.

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The Company’s Tariff, PSC No. 220, states that the Company is not responsible for the adequacy or safety of the Customer's equipment or wiring. Further, the Company reserves the right to discontinue service whenever the Customer fails to maintain such equipment and wiring in a safe and adequate condition or fails to utilize electricity in such a manner as to avoid interference with the service furnished by the Company to other customers, or with the use of service by the Customer or others.

ESB 755 O&M Requirements – Section 1.1.1

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ESB 755 – Section 2.0 Customer Responsibility

1. Equipment shall meet National Grid specs

2. Up to date drawings

3. Qualified O&M personnel

4. Protective relay testing

5. National Grid witness of relay functionality

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ESB 755 – Section 3.2 Operating Protocol

1. For mutual interest of the service connection

2. Customer to follow switching protocol with the National Grid’s Dispatch & Control Center

3. Customer to have switching instructions for energization under normal and abnormal situations

4. Approach distance to National Grid-energized facilities shall be adhered

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1. Customer shall perform proper O&M on station

2. Customer shall provide qualified personnel and tools

3. Access to National Grid metering spaces

4. Protective relay testing every 2 to 6 years

5. Submit written affirmation that testing has been completed upon request.

ESB 755 Section 4.0 Routine Maintenance

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ESB 755 Requirement for Documenting Routine Maintenance

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Proper EPM can prevent this!

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Questions?

What we covered:

NFPA 70B and NETA-MTS for maintenance inspection of medium and high voltage equipment.

National Grid’s ESB 755.