ML20196D628

Part 21 Rept Re Potential Defect in Certain Model RTF-480/120-30 Ac Line Regulating Transformers Involving Nuisance Tripping of 100 Ampere Ac Input Circuit Breaker When Initializing Unit.Breaker Should Be Replaced

ML20196D628
Person / Time
Site:	Crystal River, Rancho Seco, 05000000
Issue date:	02/10/1988
From:	Behr M PCP, INC.
To:	NRC
References
REF-PT21-88-013-000 PT21-88-013-000, PT21-88-13, NUDOCS 8802170305
Download: ML20196D628 (3)

Text

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-I forty two east Street, p o. box 380, crystet take. imnots 60014. telephorts: 815/459-9100, twx 910.634-3356. fs 615/459-9118 I

power conversion productsInc

/

February 10, 1988 Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission  !

Washir' ton, DC 20555

Subject:

10 CFR Part 21 Power Conversion Products has discovered a potential defect in certain Model RTF-480/120-30 A.C. line regulating transformers. The specific model numbers, serial numbers, and stations utilizing these A.C. line regulators have been determined and appropriate site personnel have ,

been notified by phone at this time. The two nuclear stations that are in possession of the suspect equipment are: Sacramento Municipal Utility District Rancho Seco Station and Florida Power Corporation  !

Crystal River Unit 3.

The potential defect involves nuisance tripping of the 100 ampere A.C. .

input circuit breaker when initializing the unit. Depending upon the characteristics of the A.C. feed into the RTF, the inrush current drawn by the RTF may be within the instantaneous trip range of the breaker, which would cause occasional tripping of the breaker upon initializing of the unit.

Power Conversion Products recomends replacing the 100 ampere circuit I breaker with a 225 ampere non-automatic breaker to prevent the nuisance -

tripping upon energization.

This notice has been sent to the utilities that have these A.C. line I regulators, copies are enclosed.

i POWER CONVERSION PRODUCTS INC. '

[

Michael Behr Manager, Quality Assurance ,

MB/jr '

Enclosures:

2 Letters i

8802170305 880210  !

PDR ADOCK 05000302 l@

S PDR 1 t 1 i

forty two eist street, p o. box 380. crystal saka, itfiros 60014, tilephorse: 815/459 9100. twa 910434 3356. faz 815/459-9118  ;

power conversion products Inc .

February 10, 1988 Sacramento Municipal Utility District Rancho Seco Nuclear Generating Station ,

14440 Twin Cities Road .

Herald, CA 95638-9799 Attn: Mr. Thomas Fetterman/ Jim Hayes Electrical Engineering Manager

Subject:

10 CFR Part 21

Dear Mr. Fetterman,

t Power Conversion Products has discovered a potential defect in certain i

Model RTF-480/120-30 A.C. line regulating transformers. This potential ,

i defect is not in all Model RTF-480/120-30 A.C. line regulators; however, the units with serial numbers 22204-101 thru 104 and 29786-101 thru 104 I l  !

which are in vour possession, may exhibit this potential defect.

The potential defect involves nuisance tripping of the 100 ampere A.C.  :

input circuit breaker when initializing the unit. Depending upon the characteristics of the A.C. feed into the RTF. the inrush current drawn i by the RTF may be within the instantaneous trip range of the breaker, ,

which would cause occasional tripping of the breaker.  ;

r i Power Conversion Products recomends replacing the 100 ampere circuit breaker with a 225 ampere non-automatic breaker to prevent the nuisance  !

l tripping upon energi:ation. We will be pleased to furnish the replace- '

ment breaker at no cost to you providing the original breaker is returned

)

to us in good condition.

l l'

Should you have further questions regarding this matter, contact me at l 815-459-9100. l f

Sincerely,  ;

1  :

POWER CONVERSION PRODUCTS INC.

f/fp l Michael Behr 1 Manager, Quality Assurance l

cc: Director. Office of Inspection and Enforcement l U.S. Nuclear Regulatory Comission  ;

,' Washington, DC 20555  !

f l

__m , . ._. ._.. . . __- -. .

._ . -'w forty two east street, p o boa 380. crystallate Enos 60014. telephone: 815'459-0100, twa 910$34 3356 fax 81s/459 9118 I

power conversion productsinc r

february 10, 1988 Florida Power Corp. ,

4 Crystal River Plant Unit 3 4

P.O. Box 219 Crystal River, FL 23629  !

Attn: fir. George Oberndorfer NT20 Manager Procurement Quality Assurance

Subject:

10 CrR Part 21 J

Dear Mr. Oberndorfer,

j Power Conversion Products has discovered a potential defect in certain '

Model RTF-480/120-30 A.C. line regulating transformers. This potential defect is not on all Model RTF-480/120-30 A.C. line regulators; however, .

the units with serial numbers 26678-101 thru 104, your equipment number VBTR-4A thru 40, may exhirit this potential defect. l l The potential defect involves nuisance tripping of the 100 ampere A.C.

input circuit breaker when initializing the unit. Depending upon the ,

characteristics of the A.C. feed into the RTF, the inrush current drawn i by the RTF may be within the instantaneous trip range of the breaker, i which would cause occasional tripping of the breaker. l 2

Power Conversion ?reducts recommends replacing the'100 ampere circuit -

l breaker with a 225 ampere non-automatic breaker to prevent the nuisance  ;

tripping upon energization. We will be pleased to furnish the replace-l ment breaker at no cost to you providing the original breaker is returned  ;

J to us in good condition, j Should you have further questions regarding this rnatter, contact me at i 1 815-459-9100, j 4

i l Sincerely, '

i I -

j POWER CONVERSION PRODUCTS INC.

YA Michael Behr ,

I Manager, Quality Assurance  !

cc: *)irector, Office of Inspection and Enforcement  :'

l U.S. Nuclear Regulatory Comission ,

! Washington, DC 20555

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