ML20067C290

Proposed Tech Specs,Expanding Testing Tolerence of 480 Volt Molded Case Circuit Breakers

ML20067C290
Person / Time
Site:	Limerick
Issue date:	01/31/1991
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML20067C287	List: ML20067C286 ML20067C290
References
NUDOCS 9102120017
Download: ML20067C290 (3)

Text

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B ATTACHMENT 2 LIMERICK GENERATING STATION UNITS 1 AND 2 Docket Nos. 50-325 50-353 License Nos. NPF-39 NPF-85 PROPOSED TECHNICAL SPECIFICATION CHANGE No. 87-05-0 List of Attached Page Changes Unit 1 Unit 2 3/4 8-22 3/4'8-22 l-9102120017 910131 POR ADOCK 05000352 PDR ,

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' ELECTRICAL POWER SYSTEMS-e SURVEILLANCE REQUIREMENTS--(Continued)

2. - By selecting and functionally testing a representative sample of at least 10% of each type of 480 VAC circuit breakers. Circuit breakers selected for functionel-testing shall be selected on a rotating basis.- Testing of ttese circuit breakers shall consist of injecting a current with a vefue equal to 300% of the pickup of the long time delay trip element and 150% of the pick up of the short-time delay trip element, and verifying that the circuit breaker operates within the time delay bandwidth for that current specified by the manufacturer. The instantaneous element shall be tested by injecting a current equal to -20%/+40% of the pickup value of the ~l element and verifying that the circuit breaker trips-instantaneously with no intentional time delay. Molded case circuit breaker testing shall also follow this procedure except that generally no more than #

two trip elements, time delay and instantaneous, will be involved.

Circuit breakers found-inoperable during functional testing shal.1 be restored to OPERABLE status prior to resuming operation. For.each circuit breaker found inoperable during these functional tests, an additional representative sample of at least 10% of all the circuit breakers of the inoperable type shall also be functionally tested-until-no more failures are found or all circuit breakers of that type have been functionally tested.

b. At least once per 60-months by subjecting each circuit breaker to o inspection and preventive maintenance in accordance with procedures prepared in conjunction with its manufacturer's recommendations.

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-LIMERICK - UNIT _1_ 3/4 8-22 L . , =. -

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"+ . " . .ELECTRICAL POWER SYSTEMS 4.

SURVEILLANCE REQUIREMENTS (Continucd)

2. By selecting and functionally testing a representative sample of at ]

least 10% of each type of 480 VAC circuit breakers. C ircuit '

breakers selected for functional testing shal_1 be selected on e rotating basis. Testing of these circuit breakers shall consist of injecting a current with a value equal to 300% of the pickup of the long time delay trip _ element and 150% of the pick up of the short time delay trip element, and verifying that the circuit breaker operates within the time delay bandwidth _for that current specified by the manufacturer. The instantaneous element shall be tested by 9; injecting a current equal to -20%/+40% of the pickup value of the element and verifying that the circuit breaker trips instantaneously l1 with no intentional time delay. Molded case-circuit breaker testing shall also follow this procedure except that generally.no more than two trip elements, time delay and instantaneous, will be involved.

i Circuit breakers fuund inoperable during functional testing shall be l restored to OPERABLE. status prior to resuming operation. For each:  !

circuit. breaker found inoperable during these functional tests, an i additional representative sample of at least 10% of all the circuit breakers of the inoperable type shall also be functionally tested l until no.more failures are found or all circuit breakers of that type have-been functionally tested.

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b. At least once per 60 months by subjecting each circuit breaker to an 1 inspection and preventive maintenance in accordance with procedures -i prepared in conjunction with its manufacturer's recommendations.

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L LIMERICK - UNIT 2 3/4 8-22 ,