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ACCESSION #: 9503100006 MKW POWER SYSTEMS, Inc. March 2, 1995 Walter Haass NRC Office of Nuclear Reactor Regulation 11555 Rockville Pike Rockville, MD 20852 Reference: Report No. 10CFR21-0070 Subject: Reportable detect with Potter & Brumfield relay Potter & Brumfield #R10-E3286-2 (C&D #JR-461-E) C&D HVSD Printed Circuit Board #MBC-2920-E Dear Mr. Haas: Enclosed is a copy of report no. 10CFR21-0070 concerning a reportable defect with a Potter & Brumfield relay used in some C&D battery chargers. This report is being mailed today to G.E. Nuclear, our only customer affected by this notification. Yours very truly, MKW POWER SYSTEMS, INC. Michael Nuding General Manager - Quality Assurance MN:dg Enclosure Post Office Box 1928 o Rocky Mount, North Carolina 27802-1928 o Phone: (919) 977-2720 TWX: (510) 929-0725 o FAX: (919) 446-3830 MKW POWER SYSTEMS, Inc. 301 South Church Street Station Square, Suite 100 Rocky Mount, NC 27804 Phone: (919) 977-2720 TWX: (510) 929-0725 FAX: (919) 446-1134 TELEFAX DATE: March 1, 1995 COMPANY: Office of Nuclear Reactor Regulation FAX NUMBER: 301-504-1887 ATTENTION: Mr. Thomas Murley REFERENCE: Report #10CFR21-0070 FROM: Michael Nuding IF YOU DO NOT RECEIVE ALL PAGES LISTED, PLEASE CALL EXTENSION 253. PAGES (INCLUDING COVER SHEET): 6 Dear Sir: Following this cover is a copy of Report No. 10CFR21-0070 concerning a reportable defect reported by C&D Charter Power Systems for Potter & Brumfield relay #R10-E3286-2 (C&D #JR-461-E) used on C&D printed circuit board #MBC-2920-E. This report will be mailed tomorrow to G.E. Nuclear, our only customer affected by this notification. We understand that this defect was reported to the NRC in September, 1994 by C&D, but MKW Power Systems was not notified until 2/27/95. A copy of the report is being mailed to you under a separate cover. Should you have questions, please let us know. Sincerely, MKW POWER SYSTEMS, INC. Michael Nuding General Manager-Quality Assurance MKW POWER SYSTEMS, Inc. Report No. 10CFR21-0070 March 1, 1995 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Potter & Brumfield relay #R10-E3286-2 (C&D #JR-461-E) C&D HVSD Printed Circuit Board #MBC-2920-E SYSTEM: C&D Type ARR battery chargers. CONCLUSION: Defect is Reportable in Accordance with 10CFR21 PREPARED BY: DATE: Donald D. Galeazzi Engineering Manager PREPARED BY: DATE: Michael Nuding General Manager, Quality Assurance Post Office Box 1928 o Rocky Mount, North Carolina 27802-1928 o Phone: (919) 977-2720 TWX: (510) 929-0725 o FAX: (919) 446-3830 REPORT NO. 10CFR21-0070 PAGE: 1 OF 2 SUMMARY MKW Power Systems received notification on 2/27/95 from C&D Charter Power Systems (see Exhibit 1) about a 10CFR21 reported mechanical defect in the latching mechanism of Potter & Brumfield #R10-E3286-2 relays (C&D #JR- 461-E). The relay is used on C&D High Voltage Shut Down Alarm Assembly Printed Circuit Board #MBC-2920-E used in C&D Type ARR battery chargers. The defect (filed to the NRC in 9/94) has been identified as a dimensional non-conformance in the latching mechanism of the relay. The defect is limited to two date code lots of material identified as lots 9108 and 9242. Failure of the relay may cause an apparent High Voltage Shut Down of the battery charger, terminating charging of the battery system until such time as the relay is reset; or, it may result in a false alarm without shutdown of the battery charger. The batteries themselves will be unaffected unless the shutdown condition is not corrected for a sufficient period of time which allows the batteries to discharge due to usage without recharging. COMPONENTS Potter & Brumfield relay #R10-E3286-2 (C&D #JR-461-E) C&D HVSD Printed Circuit Board #MBC-2920-E CUSTOMERS AFFECTED G.E. Nuclear: C&D #MBC-2920-130B-E, customer P.O. #205-93R431 C&D #MBC-2920-130B-E, customer P.O. #205-93R505 DEFECT The defect has been identified as a dimensional non-conformance in the latching mechanism of the relay. The defect is limited to two date code lots of material identified as lots 9108 and 9242. The lot code is located on the front of the relay. Lot 9108 and 9242 were manufactured by Potter & Brumfield on 2/22/91 and 10/30/92 respectively. C&D is not able, however, to trace which boards these particular lots of relays were used on. CORRECTIVE ACTION 1) Check HVSD Printed Circuit Board in battery charger(s) or in stock to assure that the relay on the board in not from one of the suspect lots. 2) Any boards which contain relays from the suspect lot may be checked by performing the following: A defective relay may be identified by a simple pull test on the reset button. A defective relay, when in the latched (pushed in) position, will easily release when pulled on. A good relay will take considerable force to release. 3) Any boards which contain relays from the suspect lot may be returned for repair or replacement. REPORT NO. 10CFR21-0070 PAGE: 2 OF 2 EXHIBIT 1 (2 pages) C&D NOTIFICATION LETTER TO MKW POWER SYSTEMS C&D CHARTER POWER SYSTEMS (Registered Trademark) 3043 Walton Road Plymouth Meeting, PA 19462 Telephone (215) 828-9000 FAX (215) 834-7306 February 27, 1995 MKW Power Systems, Inc. 301 South Church St. Suite 100 Rocky Mount, NC 27802 Dear Don Galeazzi: In September of 1994 C&D filed a part 21 notification with the NRC Operations center stating that a mechanical defect had been found in the latching mechanism of Potter and Brumfield R10-E3286-2 relays (C&D Part Number JR-461-E) which may effect 1E safety related chargers in the field. The relay is found on C&D High Voltage Shut Down Alarm Assembly Printed Circuit Boards (MBC-2920-E) used in C&D ARR Chargers. The failure has been identified as a dimensional non-conformance in the latching mechanism of the relay. The defect is limited to two date code lots of material identified as lots 9108 and 9242 on the relay. The lot code is located on the front of the relay. Failure of the relay may cause an apparent High Voltage Shut Down of the Charger terminating charging of the battery system until such time as the relay is reset, or it may result in a false alarm without shutdown of the charger. The battery itself will be unaffected unless the shutdown condition is not corrected for a sufficient period of time for the batteries to become discharged. For this reason we do not believe that the failure mode poses an imminent danger. We have identified a time period during which these boards were available, but are not able to trace which boards these particular lots of relays were used on. Lot 9108 was manufactured by Potter & Brumfield on February 22, 1991. Lot 9242 was manufactured by Potter & Brumfield on October 30, 1992. All chargers which use this relay or replacement boards that were sold from February 22, 1991 until the present. Our records indicate that MKW Power Systems, Inc. purchased on Purchase Order(s) 71053 and 71781, equipment which may be effected by this relay. A list of chargers, boards and parts which can contain this relay is attached to this letter. A defective relay may be identified by a simple pull test on the reset button. A defective relay when in the latched (pushed in) position will easily release when pulled on. A good relay will take considerable force to release. Boards that are suspected of having defective relays may be tested by the purchaser or returned to C&D for test and repair or replacement. You are advised to check the HVSD Printed Circuit Board in your charger or stock to assure that the relay on the board is not from one of the suspect lots. Any boards which contain relays from the suspect lot may be returned to C&D for testing and repair or replacement. If you have further questions or need to return a board for repair or replacement please contact Graham Walker at 800 543-8630 ext. 316. Sincerely, T. (illegible) Kinden Director Quality Assurance cc: MKW Power Systems, Inc. file Product Safety Committee file G. Walker RS-896 ARR Model Chargers utilizing the MBC-2920 HVSD Alarm Board MODEL SPECIFICATION S- HVSD BOARD MBC - XXXX-E XXXX ARR24AC25F 2954-E 2920 ARR130HK50 1567-E 2920 ARR130HK50 2647-E 2920 ARR1300HK75F 2370-E 2920 ARR130HK100F 2370-E 2920 ARR130K150F 4062-E 2920 ARR1300K150F 2480-E 2920 ARR130K200 2588-E 2920 ARR130K200 2648-E 2920 ARR130K200f 3553-E 2920 ARR130K200F 3191-E 2920 ARR130K200F 2764-E 2920 ARR130K300 2368-E 2920 ARR130K300F 2955-E 2920 ARR260K50F 2721-E 2920 ARR260K200F U3644-E 2920 In addition, any of the 2920 series of High Voltage Shut Down (HVSD) boards which were puchased as spare or replacement parts. *** END OF DOCUMENT ***