Part 21 Report - 1996-190
ACCESSION #: 9602070151
ABB
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
specifications.
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
ABB.
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
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