ML20008G126

Part 21 Rept Re Potential Problem W/Overcurrent Relays ITE-50H & ITE-50D Series Produced from 1976 to Oct 1980. Relays May Not Drop Out Upon Reduction in Current.Company Taking Steps to Notify Relay Users

ML20008G126
Person / Time
Site:	Beaver Valley, Oconee, Hope Creek, River Bend, South Texas, Comanche Peak, Midland, Bellefonte, 05000355, Washington Public Power Supply System, Hartsville, Phipps Bend
Issue date:	06/16/1981
From:	Duvall D BBC BROWN BOVERI, INC. (FORMERLY BROWN BOVERI CORP.
To:	Stello V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-PT21-81-449-000 PT21-81-449, PT21-81-449-000, NUDOCS 8107020306
Download: ML20008G126 (3)

Text

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-  ! Brown Boveri Electric, Inc.

Manufacturer of I-T-E Electrical Power Equipment f hf'f OO O June 16, 1981 3 pg

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S7 $BF c-Mr. Victor Stello, Jr. D p Director,  %.

Office of Inspection & Enforcement Wj'74j} /

U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Stello:

The purpose of this report is to advise the Nuclear Regu:.atory Commission of the potential prcblem with overcurrent relays manufastured by Brown Boveri Electric, Inc. These relays are the ITE-50H and ITE-50D Serics produced from 1976 through Octobar, 1980. These relays are designated as "High-dropout" units. This means that they should be self-resetting when the current drops slightly below t.t.e pickup setting. BBEL published data states that the contacts should drop out when the input current to che relay falls below 98% of ,the pickup setting.

The nature of the potential problem is that the relav may not drop out upon the reduction in enrrent. This is due to un integrated circuit designated as U4 cn the drawout printed circuit board of the relay. The integrated circuit is manufactured in two versions designated as the "A" chip and the "B" chip. The relays. manufactured with the "A" chip are susceptible to the problem described above. Relays manufactured with the "B" chip version are not susceptible to the problem.

The integrated circuit, manufactured by RCA is not defective. The "B" chip is not dependent on rise and fall time for this application. Testing has demonstrated that not all the "A" chips could successfully duplicate the potential problem.

The integrated circuit may be identified by numbers printed on its body.

The "A" chip is identified with the numbers 4047A and the "B" chip is identified with the numbers 4047B. (Thera may be additional prefix and suffix letters, but only the four digits and the first following letter are of consequence).

For inspection purposes, the dravout circuit board may be withdrawn from its case while in service without causing any CT circuits to be open-circuited; however, all output contacts will appear to revert to the open state.

Switchgear Systems Division k

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v -_, San,ng House, PA 19477. + (215) 628 7400

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5810-7020'306

3 3 C Brown sovari electric, Inc.

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Page 2 June 16, 1981 There have been no reported problems with these overcurrent relays at any of the Nuclear Power Generating Stations where they are being used. BBEL is taking steps to notify these users of the potential problem in order that corrective action can be implemented at their convenience.

A list of the location and approximate number of overcurrent relays with this potential problem are included as an attachment to this letter. If you require any additional information on this matter, please contact Mr. E. W. Rhoads at 215-628-7660.

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D. . UVALL ice' President General Manager Switchgear Systems Division EWR/jm Attaciment ec: ti. D. Breder D. Dalasta C. L. Downs W. E. Laubt.ch E. W. Rhoads C. J. Village I

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BBEL SWITCHGEAR WITH ITE-50D OR 50H OVERCURRENT RELAYS APPROXIMATE ITE SALES ORDER LOCATION NO. OF UNITS 33-50651 Duquesne Light / Beaver Valley II 20 33-51014 TVA/Bellefonte 50 33-51128 Gulf States Utilities / River Bend 4 33-51261 Texas Utilities Services Inc./

Comancb.e Peak 120 3F 51659 Washington Public Power Supply System /WNP 1 & 4 110 33-52224 & 33-52260 Public Service Gas & Electric /

Hope Creek 17 37-52313 TVA/Hartsville 1 & 2 25

. 37-52449 TVA/Hartsville 3 & 4/Phipps Bend 1&2 1 37-52454 TVA/Hartsville 3 & 4/Phipps Bend 1&2 12 33-52769 & 33-52914 Houston Light & Power / South Texas Project 6 33-53566 Duke Power /Oconee 2 NOTE: This list includes all 50D & 50H overcurrent relays in the equipment, only a pcMion of which are used in Class lE applications.

OVERCURRENT RELAYS SOLD TO ORIGINAL EQUIPMENT MANUFACTURERS APPROXIMATE ITE SALES ORDER LOCATION NO. OF UNITS 34-24662/3 HK Porter / York Electropanel Washington Public Power Supply System WPN 1 & 4 43 34-29584 Golden Gate Switchboard Taiwan Power 4 34-32354 Systems Control Corp.

Duquesne Light / Beaver Valley II 2 34-34770 Gould, Pinksburg, Md.

Consumers Power / Midland Project 4 4,qs &. , ff/ c' . o;r ; ,- -( ,a 2 t, , .g ,. t ';, , q, Je _, ,

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