United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 88-69, Supplement 1: Movable Contact Finger Binding in HFA Relays Manufactured by General Electric (GE)

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                             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)


All holders of operating licenses or construction permits for nuclear power 


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.

.                                                       IN 88-69, Supplement 1 
                                                       September 29, 1988 
                                                       Page 2 of 2 


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 

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. 

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 

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 

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 
Page Last Reviewed/Updated Friday, May 22, 2015