Information Notice 1992-05, Potential Coil Insulations Breakdown in Abs RXMH2 Relays
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
January 8, 1992 NRC INFORMATION NOTICE 92-05:
POTENTIAL COIL INSULATION BREAKDOWN
IN ABB RXMH2 RELAYS
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice
to alert addressees to a potentially safety-significant problem involving the
coil insulation breakdown in Asea Brown Boveri (ABB) RXMH2 relays. It is
expected that recipients will review the information for applicability to their
facilities and consider actions, as appropriate, to avoid similar problems.
However, suggestions contained in this information notice are not NRC require- ments; therefore, no specific action or written response is required.
Description of Circumstances
On August 12, 1991, United Controls Division of Hub, Incorporated, (United
Controls) notified the NRC in accordance with Part 21 of Title 10 of the
Code of Federal Regulations (10 CFR Part 21) concerning the failure of an ABB
RXMH2 relay being used in the emergency diesel generator (EDG) bus load
sequencing panels at the Florida Power & Light Company's Turkey Point
Generating Station.
The failed relay, one of approximately 300 ABB relays
installed at Turkey Point, had failed to change state upon being energized
during a preoperational test.
United Controls purchased the relay from ABB as
a commercial grade item and dedicated the relay for safety-related use as part
of Turkey Point's EDG sequencing panels. On August 16, 1991, ABB also notified
the NRC in accordance with 10 CFR Part 21 and provided further information
concerning the failed relay.
Discussion
ABB conducted a failure analysis and found that the coil in the relay had
suffered a short circuit of the windings at the point at which the beginning
lead of the coil was crossed by the subsequent windings of each layer of wire
as they were wound onto the coil spool.
The beginning lead and the subsequent
windings were to be separated by a piece of clear plastic adhesive tape placed
over the beginning lead to hold it in a channel in the end flange of the coil
spool.
The separation tape would then hold the beginning lead in place and
prevent abrasion from the subsequent windings during the winding process.
However,,o
xamining the failed coil, ABB determined that during the winding
{D~-i
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IN 92-05 January 8, 1992 process, the tape had been pulled back and dislocated away from the beginning
lead it was supposed to hold in the end flange channel of the coil spool. Some
of the varnish insulation on the beginning lead was then apparently abraded
during the winding process, allowing the insulation breakdown which caused the
relay to fail.
ABB inspected other relays, none of which had yet failed, to determine if the
separation tape was adequately placed. The acceptance criterion established by
ABB specified that the separation tape must cover the beginning lead with an
overlap margin of 1.0 millimeter (mm) or greater. Although none of the relays
had damaged or dislocated separation tape, ABB found that almost all of them
had less than 1.0 mm of margin.
United Controls and ABB determined that the problem had generic implications
but that the scope was limited to relays with the particular coil design in
question (type RXMH2, Models RK223068-EA and RK223069-EA) manufactured from
March 1989 through September 1990. ABB identified the root cause of the
problem as the performance of one factory employee who had manufactured relays
within the date codes cited above.
ABB has made a design change to reposition the separation tape on the end
flange of the coil spool to more evenly cover the beginning lead and avoid
conditions that could cause the separation tape to be dislocated during the
winding process. ABB has also taken action to ensure that all pertinent draw- ings and procedures have been updated and corrected and that all affected
employees have been trained on the changes.
The manufacturer, ABB, did not believe that field data indicated a reliability
problem with the type RXMH2 relay but recommended that in applications in which
a failure to operate could cause a substantial safety hazard, the relays be
checked for coil insulation integrity.
The RXMH2 relays having the potential for insulation breakdown were manufac- tured from March 1989 to September 1990.
The relays are marked in the upper
right corner of the legend plate with the year and week of manufacture; the
dates of concern indicated as 8909 up to, and including, 9036.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact:
Bill Rogers, NRR
(301) 504-2986 Attachments:
1 JB 10 CFR Part 21 Notification to the NRC
Last of Recently Issued NRC Information Notices
IO B'EIt
ASEA BROWN BOVERI
Attachment 1 IN 92-05
January 8, 1992 August 16, 1991
Director, Office of Nuclear Reactor Regulation
US Nuclear Regulatory Commission
Washington, D.C.
20555 Subject:
Notification of Potential Generic Defect
Per 10CFR Part 21 Notification By:
ABB Power T&D Company Inc., Relay Divisions
4300 Coral Ridge Drive
Coral Springs, FL 33065
William H. Wallace
Manager Total Quality & Process Technology
(305) 752-6700
On August 12, 1991, United Controls Division of HUB Inc. submitted
notification to the Director, Office of Nuclear Reactor Regulation of
a potential generic component defect found during an inspection of
ASEA/ABB Type RXMH2, Model RK223068-EA and RK223069-EA relays at
Florida Power and Light's Turkey Point Units 3 and 4. ABB Power T&D
Company, Inc. has marketing responsibility for this product in the
United States. The product is manufactured in Sweden by an
affiliate. ABB Power T&D Company Inc. also has responsibility for
notifications, customer contacts and similar items, and it is in this
capacity that this notification is
made.
Additional investigation has confirmed that all type RXMH2 AC or DC
voltage operated heavy duty auxiliary relays manufactured from March,
1989 until September, 1990, have the potential for coil insulation
breakdown.
This coil configuration is unique to the type RXMH2
relay.
Investigation of sales records indicates that the type RXMH2 relay has been sold as a commercial grade component for protection
and control systems to a wide variety to customers.. Many of the
RXMH2 relays are sold to original equipment manufacturers for
incorporation into systems purchased by utility end users.
Relay
customers are being notified through the following message sent
August 15, 1991, to all ABB Power T&D Field Sales offices for
transmittal to original equipment manufacturers who may have
purchased RXMH2 relays and to utility customers who may have these
relays installed ir. nuclear facilities.
ABB Power T&D Company Inc.
Relay
Division
4300 Coral Ridge Drive
Coral Springs. FL 33065
Telephone: (305) 752-6700
Telefax:
(305) 345-5329
91BW160
Attachment 1
January 8, 1992
August 16, 1991 Page Two
"ABB was recently notified of the failure of a typ4 RXMH2 heavy duty auxiliary relay.
operated auxiliary relay is especially suited for
protective relaying and industrial applications requiring
electrically independent multiple contacts with high
breaking capacity and are often applied in parallel with
fast operating trip relays.
Examination of the failed.. ,,'
relay revealed insulation breakdown at the coil
termination.
This mode of failure will cause the relay to
-
fail to operate under fault conditions.
This problem is.
caused by the misplacement of insulating tape installed on
the coil termination during assembly of the product.
Examination of additional RXMH2 units at the same customer.
installation indicates that this condition may occur on
other RXMH2 units.
Further investigation has shown that
this deviation in assembly procedure may have occurred in
units manufactured from March, 1989 until September, 1990.
Each relay is marked in the upper right corner of the
legend plate with the year and week of manufacture (e.g.
9036).
The relays that may have this problem are the type
RXMH2 marked 8909 up to and including 9036.
Field data does not indicate a reliability problem with
this component.
However, ABB is aware of application of
the RXMH2 auxiliary relays in protection and control
systems of U.S. nuclear installations.' RXMH2 relays in;
applications where a failure to operate could cause a.'a'
substantial safety hazard should be checked for coil
insulation integrity.
Please contact your local ABB'Field'
Sales office or John Wilson (305-752-6700) at the Coral'
Springs Relay Division Total Quality Department for further'
information."
Prepared By:
W
L
Date:
___9__
William H. allace
Manager Total Quality &
Proce Technology
v,.
Reviewed By:
Date: 4 .
onald L. Jan
\\\\-
Vice President &
General Manager
WHW/lw
cc:
Michael Charlton/United Controls
S. Franzone/FP&L
91BW160
Attachment 2
January 8, 1992 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
92-04
92-03
92-02
92-01
91-87
91-86 Potter & Brumfield Model
MDR Rotary Relay Failures
Remote Trip Function
Failures in General Electric
F-Frame Molded-Case Circuit
Breakers
Relap5/Mod3 Computer Code
Error Associated with the
Conservation of Energy
Equation
Cable Damage Caused by
Inadequate Cable Installa- tion Procedures and Controls
Hydrogen Embrittlement of
Raychem Cryofit Couplings
New Reporting Requirements
for Contamination Events at
Medical Facilities
Potential Failures of
Thermostatic Control Valves
for Diesel Generator Jacket
Cooling Water
Problems with Criticality
Alarm Components/Systems
Solenoid-Operated Valve
Failures Resulted in
Turbine Overspeed
01/06/92
01/06/92
01/03/92
01/03/92
12/27/91
12/27/91
12/26/91
12/26/91
12/20/91
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
All licensees authorized
to use byproduct materials
for human use.
All holders of OLs or CPs
for nuclear power reactors.
All Nuclear Regulatory
Commission (NRC) fuel
cycle licensees, interim
spent fuel storage licens- ees, and critical mass
licensees.
All holders of OLs or CPs
for nuclear power reactors.
91-85
91-84
91-83 OL = Operating License
CP = Construction Permit
IN 92-05 January 8, 1992 process, the tape had been pulled back and dislocated away from the beginning
lead it was supposed to hold in the end flange channel of the coil spool. Some
of the varnish insulation on the beginning lead was then apparently abraded
during the winding process, allowing the insulation breakdown which caused the
relay to fail.
ABB inspected other relays, none of which had yet failed, to determine if the
separation tape was adequately placed. The acceptance criterion established by
ABB specified that the separation tape must cover the beginning lead with an
overlap margin of 1.0 millimeter (mm) or greater. Although none of the relays
had damaged or dislocated separation tape, ABB found that almost all of them
had less than 1.0 mm of margin.
United Controls and ABB determined that the problem had generic implications
but that the scope was limited to relays with the particular coil design in
question (type RXMH2, Models RK223068-EA and RK223069-EA) manufactured from
March 1989 through September 1990. ABB identified the root cause of the
problem as the performance of one factory employee who had manufactured relays
within the date codes cited above.
ABB has made a design change to reposition the separation tape on the end
flange of the coil spool to more evenly cover the beginning lead and avoid
conditions that could cause the separation tape to be dislocated during the
winding process. ABB has also taken action to ensure that all pertinent draw- ings and procedures have been updated and corrected and that all affected
employees have been trained on the changes.
The manufacturer, ABB, did not believe that field data indicated a reliability
problem with the type RXMH2 relay but recommended that in applications in which
a failure to operate could cause a substantial safety hazard, the relays be
checked for coil insulation integrity.
The RXMH2 relays having the potential for
tured from March 1989 to September 1990.
right corner of the legend plate with the
dates of concern indicated as 8909 up to, insulation breakdown were manufac-
The relays are marked in the upper
year and week of manufacture; the
and including, 9036.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Original Sign~df 5 Charie EL M'
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact:
Bill Rogers, NRR
(301) 504-2986 Attachments:
1. ABB 10 CFR Part 21 Notification to the NRC
2. List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCES
Document Name: IN 92-05 DRIS:VIB
DRIS:VIB
DRIS:VIB
DRIS:VIB
BROGERS
CVANDENBURGH
LNORRHOLM
BGRIMES
ON4*
A 1
.
12/12/91*
12/16/91*
CBERLINGER
12/27/91*
2_
TECH ED :
JMAIN :
12/10/91*
IN 91-XX
December XX, 1991 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact the
technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contact:
Bill Rogers, NRR
(301) 504-?986 Attachments:
1. ABB 10 CFR Part 21 Notification to the NRC
2.
List of Recently Issued NRC Information Notices
- See previous concurrences
OFC
- DRIS:VIB
- DRIS:VIR
- DRIS:VIB
- DRIS:VIB
- TECH ED
NAME :BROGERS
- CVANDElBURGH :LNORRHOLM
- BGRIMES
- JMAIN
DATE :12/12/91*
- 12/12/91*
- 12/12/91*
- 12/16/91*
- 12/10/91*
OFC
- NRR:OGCB
1,j
j :NRR:DOEA
___
__: __ ---
,2-
- -------
____--
--
--
___
___ ___ __-___ ___
___
NAME :CBERLINGER
- CROSSI
DATE :12/7/91
- 12/
/91
OFFICIAL RECORD
Document Name: ABB RELAY INFO NOTICE
IN 91-XX
December xx, 1991 year and week of manufacture, the dates of concern indicated as
8909 up to, and including 9036.
This information notice requires no specific action or written
response.
If you have any questions about the information in
this notice, please contact the technical contact listed below or
the appropriate Office of Nuclear Reactor Regulation (NRR)
project manager.
Charles E. Rossi, Director
Division of Operational Events
Assessment
Office of Nuclear Reactor Regulation
Technical Conta
Attachment:
Lct:
Bill Rogers, NRR
(301) 492-0986 List of Recently Issued NRC Info
ion Notices
concurrences
- See previous c
I
OFFICE NRR:OGCB
NRR:DOEA
NAME
CBERLINGER CROSSI
IDATE
12/
/91
12/
/91
OFFICIAL RECORD COPY
WORDPERFECT DOCUMENT NAME:
ABBRELAY.IN
This information notice requires no specific action or written
response.
If you have any questions about the information in
this notice, please contact the technical contact listed below or
the appropriate Office of Nuclear Reactor Regulation project
manager.
Charles E. Rossi, Director
Division of Operational Events
Assessment
Office of Nuclear Reactor Regulation
Technical Contact:
Bill Rogers, NRR
(301) 492-0986 Attachments:
1.
List of Recently Issued NRC Information Notices
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