ML20062D935

Part 21 Rept Re Failure of 4.16 Kv Vertical Lift Switchgear, cell-mounted Auxiliary Contacts to Operate on Command During Testing of Standby Switchgear at Plant.Caused When Maladjusted Test Link Inserted Between Breaker & Switch

ML20062D935
Person / Time
Site:	Callaway
Issue date:	11/01/1990
From:	David Jones GENERAL ELECTRIC CO.
To:	Taylor J NRC
References
REF-PT21-90 NUDOCS 9011190138
Download: ML20062D935 (1)

Text

i+. . .. . o . w <t-iv-.. . n-ws u nad 10*d "Idici

.  : . 4 i

f . 1 w n, , a.m.,y 1

& Centret

, l 1

k.e evi kne I teco Ft.w : cms 69:1 i % D:3 LO M PLo.w.nc. ha 19142 .

m y 1, gypn  !!$ M 2626 Subjoeta et magne-blast Circuit areakers 4.16 kV switohgear at callaway Nuotour eenerating station Union 31eetric ca.

i humiliary switch Pailure Due to sending of Operating can During Maintenanos

]

James Taylor, Director U. 8. Nuolear Regulatory commission washington, D.C.

J .

Dear Mr. Taylor l We received a report of the failure of 4.16kV vertical-lift switchgear, cell j

.- mounted, auxiliary eentacts to operate on command during the testing of  ;

i musiitary stand-by switchgear at callaway Muclear eenerating station by Mr. T.

Booper of Union Bloctric Co. j The failure has been analysed by the sustomer, and we concur, that when an improperly adjusted test link is inserted between the breaker (in the withdrawn position) and the stationary auxiliary switwh, the design Le such-  ;

that excessive force may be applied to the. actuating som en the breaker '

operating shaft, causing the cam to be deformed. 'When the breaker is then inserted in the cubicle (in the connected position), there is insufficient vertical cas travel to operate the cell mounted auxiliary owitch. ,

i

we are presently shipping modified oceeercial grade material to Union 31eetric to correct this situations we will be developing dooumontation for safety related use where we supply such parts and will inform you and our customers i of our progress ~ and recessnondations, i

This condition can only exist where users have optional cell mounted auxiliary l switches, the optional maintenance test link, and where the link has been adjusted to apply emoessive operating f' eros.

V. ruly yoursg f

s Dean Jonea  !

(W -

product Manager,/ Breakers

! /

carl clinger,; chief - Generic communications'tranoh, NRc

, via fam ,(301) 492-0260 M.C. Neal, GE, King of Prussia

. vat fast (715) 964-7673

/ / .b

0. Strambach, 43 NEPO, San Jose via fax: (408) 925-4454 ,

9011190138 901ici EDR

' (p p ADoCK 05000403 e PDC * ' '-

.. - - . . .-. - - . . . . , - . - . - - - . - . . . . . + - . - - . . -