United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9602070151


                            ASEA BROWN BOVERI

Director, Office of Nuclear Regulation

U.S. Nuclear Regulatory Commission

Washington, DC 20555

January 25, 1996

Subject:  Notification of Potential Defect per 10CFR Part 21

          Dc Telephone Relays Used in Class 1E Electromechanical Relays

Notification By:    Cheryl A. Dahle

                    Division Quality Manager

                    ABB Power T&D Company Inc.

                    Relay Division

                    4300 Coral Ridge Dr.

                    Coral Springs, FL 33065

This letter is a notification of a potential defect of the dc "T"

telephone relay used in Class 1E electromechanical relays.

On September 13, 1995, the Relay Division received a type CVE-1 Class 1E

relay for repair of the ac telephone relays V1 and V2 per our June 28,

1995 Part 21 Notification.  During inspection, it was found that the tape

on the dc telephone relay coil was discolored.  ABB and the telephone

relay manufacturer conducted an investigation of the telephone relay.  At

a nominal voltage of 125 Vdc, the telephone relay dissipates 3.125 watts.

At the upper limit voltage of 140 Vdc, the telephone relay dissipates

3.92 watts.  The manufacturer's rating of the telephone relay is 4.3

watts, continuously energized.  The telephone relay is used as an output

trip device and is normally intermittently energized.  Some applications

cause the telephone relay to be continuously energized, which would

accelerate a discolored tape condition.  The investigation of this

returned CVE-1 relay revealed that the telephone relay was fully

operational and that the operating conditions were within the design


On December 27, 1995 a type COV-8 relay and on January 4, 1996 a type

CVE-1 relay were returned for discolored and failed dc telephone relays.

As previously determined, the telephone relay's operating conditions were

within their design specifications.  However, due to these failures we

have concluded that this is a potential defect per 10CFR Part 21.  ABB

has taken action to improve the design of the telephone relay and related

circuitry.  Effective November 1, 1995, a new telephone relay with a

higher thermal rated wire and tape is being used, and a current limiting

resistor has been added.

                       ABB Power T&D Company Inc.

          Relay     4300 Coral Ridge Drive   Telephone: (305) 752-6700

          Division  Coral Springs, FL 33065  Telefax: (305) 345-5329

January 25, 1996                                              Page 2 of 2

All of the following Class 1E relays shipped prior to November 1995

contain the potentially defective dc telephone relays.  During this time

period, these relays were manufactured by and labeled as Westinghouse or


          Type                Style Number

          BL-1                1330D11A01 and A02

          CVD                 1583C32A01

          CVE                 1339D58A01 and A02

          CVE-1               1326D67A01

          COV-8               1342D82A01, A02, A03

          COV-9               1339D81A01

          KLF                 1342D88A01 and A02

          KLF-1               1342D89A01 and A02

A copy of this notification letter is being sent to all customers who our

records indicate have purchased these type of relays.  Questions

concerning this notification letter should be directed to the Quality

Manager at the Relay Division.

Cheryl A. Dahle                              Jose R. Gierbolini

Division Quality Manager                     Profit Center Manager

                                             Electromechanical Relays


Page Last Reviewed/Updated Wednesday, February 12, 2020