Transcript Preventive Maintenance/ Electric Service Equipment
Preventive Maintenance/ Electric Service Equipment
By 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
Disclaimer
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. 4
Where the Electric Utility has Mutual Interest
Electric Service Connection
which includes the service lateral, service entrance conductors, meter provision, service equipment, and grounding
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NESC applicable NEC applicable
NESC applicable for equipment under exclusive control by utility
Electrical Preventive Maintenance - EPM
Key Factor to High Reliability
Percentage of Failure Caused from Inadequate Maintenance Versus Months Since Maintained
All Electrical (months since maintained) Combined Breakers Motors Open Wire Trans- formers Less than 12 months ago 7.4% *12.5% 8.8% *0 *2.9% 12-24 months ago 11.2% 19.2% 8.8% *22.2% *2.6% More than 24 months ago 36.7% 77.8% 44.4% 38.2% 36.4% 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
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The Bottom Line of EPM
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REFERENCES for MAINTENANCE SCHEDULE
Manufacturer Instruction Manuals Refer to Station Single Line Diagram
For Main Service, Keep Serving Utility Informed of Electrical Problems
Applicable Local Rules
and Planned Changes.
( http://www.nationalgridus.com/electricalspecifications ) NFPA 70B ( http://www.nfpa.org/ ) NETA MTS ( http://www.netaworld.org/ )
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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:
15 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
Some Considerations for Electrical Inspection
ELECTRIC SERVICE ACCEPTANCE SURVEY CHECKLIST FOR USER-OWNED STATIONS - MEDIUM AND HIGH VOLTAGE
A.
1.
( reference: National Electrical Safety Code ) CLEARANCES:
Phase-to-Phase 2.
Phase-to-Ground 3.
Vertical 4.
Safety 5.
Working space
See Parts 1 and 2 in the NESC B.
STATION:
1.
Surfacing 2.
Lightning Masts
See Part 1 in the NESC
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 16
ELECTRIC SERVICE ACCEPTANCE SURVEY CHECKLIST –
cont’d
C.
SERVICE:
1.
Main Disconnect Switch
See Part 1 in the NESC
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
See Section 9 in the NESC
2.
Station Equipment and Fence 3.
Main Disc. Switch Handle and Potential Equalizing Grid 17
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: See Part 1 in the NESC and local utility requirements
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 ) 18
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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ESB 755 O&M Requirements – Section 1.1.1
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.
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ESB 755 – Section 2.0 Customer Responsibility
1.
2.
3.
4.
5.
Equipment shall meet National Grid specs Up to date drawings Qualified O&M personnel Protective relay testing National Grid witness of relay functionality
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ESB 755 – Section 3.2 Operating Protocol
1.
2.
3.
4.
For mutual interest of the service connection Customer to follow switching protocol with the National Grid’s Dispatch & Control Center Customer to have switching instructions for energization under normal and abnormal situations Approach distance to National Grid-energized facilities shall be adhered
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ESB 755 Section 4.0 Routine Maintenance
1.
2.
3.
4.
5.
Customer shall perform proper O&M on station Customer shall provide qualified personnel and tools Access to National Grid metering spaces Protective relay testing every 2 to 6 years Submit written affirmation that testing has been completed upon request.
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ESB 755 Requirement for Documenting Routine Maintenance
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
.
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