United States Nuclear Regulatory Commission - Protecting People and the Environment

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 ***

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