ML17348B506

Part 21 Rept Re Zener Diode VR2 on Power Supply Board 9 1682 00 106 Possibly Being Installed Backwards

ML17348B506
Person / Time
Site:	Cooper, Crystal River, Rancho Seco
Issue date:	10/09/1990
From:	Schwellensattl BASLER ELECTRIC
To:	Rossi C Office of Nuclear Reactor Regulation
References
REF-PT21-90 NUDOCS 9011210058
Download: ML17348B506 (5)

Text

ACCELERATED DIIBUTION DEMONST TION SYSTEM r.

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REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9011210058 DOC.DATE: 90/10/09 NOTARIZED: NO DOCKET g FACIL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C 05000250 50-251 Turkey Point Plant, Unit 4, Florida Power and Light C 05000251 50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 50-389 St. Lucie Plant, Unit 2, Florida Power & Light, Co. 05000389 50-298 Cooper Nuclear Station, Nebraska Public Power Distric 05000298 50-312 Rancho Seco Nuclear Generating Station, Sacramento Mu 05000312 AUTH. NAME AUTHOR AFFILIATION I SCHNELLENSATTL Basler Electric RECIP.NAME RECIPIENT AFFILIATION ROSSI,C.E. Division of Operational Events Assessment (Post 870411)

SUBJECT:

Part 21 rept re zener diode VR2 on power supply board 9 1682 00 106 possibly installed backwards.

DISTRIBUTION CODE: IE19D COPIES RECEIVED:LTR TITLE: Part 21 Rept (50 DKT)

/ ENCL 0 SIZE:

NOTES 05000312 D

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 PD4-1 LA PDNP LA PD2-2 PD PD4-1 PD PDNP PD EDISON,G NORRIS,J 0 CONNORE P REYNOLDS,S INTERNAL: AEOD/DSP/TPAB NRR D OGCB11 NRR/DRIS/RVIB9D 01 RES/DSIR/EIB GNl RGN2 RGN3 RGN4 RGN5 EXTERNAL: INPO RECORD CTR NRC PDR R NSIC SILVER,E NOTES:

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D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL

r Basler Electric Highland, Illinois 8OX 269, ROUTE 143 ~ HIGHLAND, IL 62249 USA. PHONE: 618I654-2341 ~ TWXI 510- 1003841 ~ FAX: 618/654 2351 October 9, 1990 Mr. Charles E. Rossi, Director Division of Operational Events Assessment U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Rossi,

On October 5, 1990, Basler Electric Company reported a possible problem to Mr. Chauncey Gould of your organization. We indicated there is a possibility that zener diode VR2 on power supply board 9 1682 00 106 may have been installed backwards. This power supply is used in Basler Electric Protective Relays. With VR2 installed backwards, resistor R I I and transistor Q2 will be thermally overstressed. This may eventually cause the power supply to quit operat-ing which would inhibit the Protective Relay from performing its design function.

'these power supplies are contained in Basler Electric Protective Relays listed below and were sold to the following companies:

~Com anv Q'"'"" 'Protective Relay Florida Power Corp. 3 '90tt339tt0 BEI-32 ELIE EIC AONIN Florida Power Corp. I F90630380 BE I -32 Ett E EIC AON I N Nebraska Public Power 3 277105 BEI-32 BLIE AIC AONON Sacramento Municipal Utility 8 GR88663 BEI-25 MIE A6C N5NIN MKW Power Systems I 63957 ~ BE 1-59 A3E CIC AONIN On October 5, 1990, Earl E. Welch of Florida Power Corp., Gary Sinclair of Nebraska Public Power and Gloria Carpenter of Sacramento Municipal Utility were notified of the possible problem. On October 8, 1990, Gene Schoeck of MKW Power Systems was notified of the possible problem.

Basler Electric will add to Acceptance Test Procedure 9 1682 00 930, per Engineering Change Authorization 11717, the following test, "measure the voltage across R22, it should be less than 0.5 Vdc". This will ensure that start-up circuit components Ql, Q2, R22, Rl I, 2 VR2 have performed their function and therefore will not be thermally overstressed. This action will be completed on October 12, 1990.

90ii210058 90i009 PDR 'DOCK 05000250 S PDC Manulacturers o1: Magnetic and Etectronlc Components ~ Power Products and Systems zy(V

'1 mP I I Air. Charles E. Rossi r'October 9, 1990

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page 2 To our knowledge this condition has not caused a Protective Relay malfunction in either a commercial or nuclear application. We recommend a visual inspection of VR2 polarity, a visual inspection for discoloring of Rl and Q2 and/or voltage measurement 1

of R22 to ensure normal operation.

If any additional information is requir'ed, please contact me.

Sincerely, BASLER ELECTRIC COMPANY c /v'~ ~<Hwirz g~c fg ~,;,-, gE.A 31m Schwellensattl Quality Engineering 3S/jks cc: Ed Leird, Basler Electric

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