Information Notice No. 88-69, Supplement 1: Movable Contact Finger Binding in HFA Relays Manufactured by General Electric (GE)
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
September 29, 1988
Information Notice No. 88-69, SUPPLEMENT 1: MOVABLE CONTACT FINGER
BINDING IN HFA RELAYS
MANUFACTURED BY GENERAL
ELECTRIC (GE)
Addressees:
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose:
This notice is provided as a supplement to Information Notice No. 88-69 to
alert recipients of additional information regarding binding of the movable
contact fingers in HFA relays manufactured by GE. It is expected that recipi-
ents will review the information for applicability to their facilities and
consider actions, as appropriate, to avoid similar problems. However, sugges-
tions contained in this information notice do not constitute NRC requirements;
therefore, no specific action or written response is required.
Description of Circumstances:
On August 12, 1988, GE submitted a written 10 CFR Part 21 notification to the
NRC concerning binding of the movable contact fingers in HFA relays. GE
stated that one user of HFA relays had reported difficulty making wipe and gap
settings on some of their HFA relays due to binding of a movable contact
finger in the phenolic finger support assembly. GE also stated that the
binding of a movable contact arm could interfere with the relay contact wipe
and gap, and that proper contact wipe and gap is necessary to maintain correct
operation and seismic rating of the relay.
Additional discussions with GE have indicated that the area of interest is
where the "pigtail" is attached to the movable contact finger. Attachment of
the "pigtail" to the movable contact finger is accomplished by "sandwiching"
the "pigtail" between the movable contact finger and a metal sleeve and then
welding the components together. It appears that this process has allowed the
production of movable contact fingers that are wider than the allowable toler-
ance. This creates the possibility that a movable contact finger will experi-
ence binding in the "H" shaped slot of the armature phenolic support assembly.
This condition affects all HFA relays with a date code prior to WC (September
1988). GE has stated that no other relays are affected.
8809230092
. IN 88-69, Supplement 1
September 29, 1988
Page 2 of 2
Discussion:
The binding condition discussed above was identified when a licensee experi-
enced difficulties making a correct wipe and gap setting after making
modifications to a relay. As discussed in Information Notice 83-19 "General
Electric Type HFA Relay Contact Gap and Wipe Setting Adjustments," a proper
wipe and gap setting is necessary to ensure that a relay can perform its
intended function. Additional information regarding making a proper wipe and
gap setting is contained in GE Service Information Letter No. 44, Supplement
4. In addition, GE has indicated that if contacts have been changed from
normally open to normally closed or vice versa by turning the fixed contact
over, or if maintenance has been performed that required partial relay
disassembly, the relay contact wipe and gap (as well as pick-up voltage)
adjustments should be checked. GE has also recommended that the wipe and gap
settings be periodically checked.
Addressees may wish to ensure that the appropriate plant personnel are aware
of the potential for binding of the movable contact fingers in HFA relays. In
addition, addressees may wish to contact GE, as appropriate, to obtain addi-
tional information regarding maintenance, adjustment, and repair of HFA
relays.
No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact one of the techni-
cal contacts listed below or the Regional Administrator of the appropriate
regional office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: Ray Scholl, NRR
(301) 492-1171
Jack Ramsey, NRR
(301) 492-1167
Attachment: List of Recently Issued NRC Information Notices
. Attachment
IN 88-69, Supplement 1
September 29, 1988
Page 1 of 1
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
_____________________________________________________________________________
Information Date of
Notice No._____Subject_______________________Issuance_______Issued to________
88-78 Implementation of Revised 9/22/88 All holders of OLs
NRC-Administered Requali- or CPs for nuclear
fication Examinations power reactors.
88-77 Inadvertent Reactor 9/22/88 All holders of OLs
Vessel Overfill or CPs for BWRs.
88-76 Recent Discovery of a 9/19/88 All holders of OLs
Phenomenon not Previously or CPs for nuclear
Considered in the Design power reactors.
of Secondary Containment
Pressure Control
88-75 Disabling of Diesel 9/16/88 All holders of OLs
Generator Output Circuit or CPs for nuclear
Breakers by Anti-Pump power reactors.
Circuitry
88-74 Potentially Inadequate 9/14/88 All holders of OLs
Performance of ECCS in or CPs for W and
PWRs During Recirculation B&W-designed
Operation Following a LOCA nuclear power
reactors.
88-73 Direction-Dependent Leak 9/8/88 All holders of OLs
Characteristics of or CPs for nuclear
Containment Purge Valves power reactors.
88-72 Inadequacies in the Design 9/2/88 All holders of OLs
of dc Motor-Operated Valves or CPs for nuclear
power reactors.
88-71 Possible Environmental 9/1/88 All holders of OLs
Effect of the Reentry or CPs for nuclear
of COSMOS 1900 and power reactors,
Request for Collection fuel cycle
of Licensee Radioactivity licensees, and
Measurements Attributed Priority 1
to That Event material
licensees.
88-70 Check Valve Inservice 8/29/88 All holders of OLs
Testing Program or CPs for nuclear
Deficiencies power reactors.
_____________________________________________________________________________
OL = Operating License
CP = Construction Permit
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