Information Notice 1992-05, Potential Coil Insulations Breakdown in ABS RXMH2 Relays

Potential Coil Insulations Breakdown in ABS RXMH2 Relays

ML031200751
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	01/08/1992
Revision:	0
From:	Rossi C E Office of Nuclear Reactor Regulation
To:
References
IN-92-005, NUDOCS 9201020171
Download: ML031200751 (9)

UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555January 8, 1992NRC INFORMATION NOTICE 92-05:POTENTIAL COIL INSULATION BREAKDOWNIN ABB RXMH2 RELAYS

Addressees

All holders of operating licenses or construction permits for nuclear powerreactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information noticeto alert addressees to a potentially safety-significant problem involving thecoil insulation breakdown in Asea Brown Boveri (ABB) RXMH2 relays. It isexpected that recipients will review the information for applicability to theirfacilities 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, (UnitedControls) notified the NRC in accordance with Part 21 of Title 10 of theCode of Federal Regulations (10 CFR Part 21) concerning the failure of an ABBRXMH2 relay being used in the emergency diesel generator (EDG) bus loadsequencing panels at the Florida Power & Light Company's Turkey PointGenerating Station. The failed relay, one of approximately 300 ABB relaysinstalled at Turkey Point, had failed to change state upon being energizedduring a preoperational test. United Controls purchased the relay from ABB asa commercial grade item and dedicated the relay for safety-related use as partof Turkey Point's EDG sequencing panels. On August 16, 1991, ABB also notifiedthe NRC in accordance with 10 CFR Part 21 and provided further informationconcerning the failed relay.DiscussionABB conducted a failure analysis and found that the coil in the relay hadsuffered a short circuit of the windings at the point at which the beginninglead of the coil was crossed by the subsequent windings of each layer of wireas they were wound onto the coil spool. The beginning lead and the subsequentwindings were to be separated by a piece of clear plastic adhesive tape placedover the beginning lead to hold it in a channel in the end flange of the coilspool. The separation tape would then hold the beginning lead in place andprevent abrasion from the subsequent windings during the winding process.However,,o xamining the failed coil, ABB determined that during the winding{D~-i 9 0217co AIN 92-05January 8, 1992 process, the tape had been pulled back and dislocated away from the beginninglead it was supposed to hold in the end flange channel of the coil spool. Someof the varnish insulation on the beginning lead was then apparently abradedduring the winding process, allowing the insulation breakdown which caused therelay to fail.ABB inspected other relays, none of which had yet failed, to determine if theseparation tape was adequately placed. The acceptance criterion established byABB specified that the separation tape must cover the beginning lead with anoverlap margin of 1.0 millimeter (mm) or greater. Although none of the relayshad damaged or dislocated separation tape, ABB found that almost all of themhad less than 1.0 mm of margin.United Controls and ABB determined that the problem had generic implicationsbut that the scope was limited to relays with the particular coil design inquestion (type RXMH2, Models RK223068-EA and RK223069-EA) manufactured fromMarch 1989 through September 1990. ABB identified the root cause of theproblem as the performance of one factory employee who had manufactured relayswithin the date codes cited above.ABB has made a design change to reposition the separation tape on the endflange of the coil spool to more evenly cover the beginning lead and avoidconditions that could cause the separation tape to be dislocated during thewinding process. ABB has also taken action to ensure that all pertinent draw-ings and procedures have been updated and corrected and that all affectedemployees have been trained on the changes.The manufacturer, ABB, did not believe that field data indicated a reliabilityproblem with the type RXMH2 relay but recommended that in applications in whicha failure to operate could cause a substantial safety hazard, the relays bechecked 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 upperright corner of the legend plate with the year and week of manufacture; thedates of concern indicated as 8909 up to, and including, 9036.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate Office of Nuclear ReactorRegulation (NRR) project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical 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'EItASEA BROWN BOVERIAttachment 1IN 92-05January 8, 1992 August 16, 1991Director, Office of Nuclear Reactor RegulationUS Nuclear Regulatory CommissionWashington, D.C. 20555Subject:Notification of Potential Generic DefectPer 10CFR Part 21Notification By:ABB Power T&D Company Inc., Relay Divisions4300 Coral Ridge DriveCoral Springs, FL 33065William H. WallaceManager Total Quality & Process Technology(305) 752-6700On August 12, 1991, United Controls Division of HUB Inc. submittednotification to the Director, Office of Nuclear Reactor Regulation ofa potential generic component defect found during an inspection ofASEA/ABB Type RXMH2, Model RK223068-EA and RK223069-EA relays atFlorida Power and Light's Turkey Point Units 3 and 4. ABB Power T&DCompany, Inc. has marketing responsibility for this product in theUnited States. The product is manufactured in Sweden by anaffiliate. ABB Power T&D Company Inc. also has responsibility fornotifications, customer contacts and similar items, and it is in thiscapacity that this notification is made.Additional investigation has confirmed that all type RXMH2 AC or DCvoltage operated heavy duty auxiliary relays manufactured from March,1989 until September, 1990, have the potential for coil insulationbreakdown. This coil configuration is unique to the type RXMH2relay. Investigation of sales records indicates that the type RXMH2relay has been sold as a commercial grade component for protectionand control systems to a wide variety to customers.. Many of theRXMH2 relays are sold to original equipment manufacturers forincorporation into systems purchased by utility end users. Relaycustomers are being notified through the following message sentAugust 15, 1991, to all ABB Power T&D Field Sales offices fortransmittal to original equipment manufacturers who may havepurchased RXMH2 relays and to utility customers who may have theserelays installed ir. nuclear facilities.ABB Power T&D Company Inc.RelayDivision4300 Coral Ridge DriveCoral Springs. FL 33065Telephone: (305) 752-6700Telefax: (305) 345-532991BW160 Attachment 1IN 92-05January 8, 1992August 16, 1991 Page Two"ABB was recently notified of the failure of a typ4 RXMH2heavy duty auxiliary relay. The RXMH2 AC or DC'voltageoperated auxiliary relay is especially suited forprotective relaying and industrial applications requiringelectrically independent multiple contacts with highbreaking capacity and are often applied in parallel withfast operating trip relays. Examination of the failed.. ,,'relay revealed insulation breakdown at the coiltermination. 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 onthe coil termination during assembly of the product.Examination of additional RXMH2 units at the same customer.installation indicates that this condition may occur onother RXMH2 units. Further investigation has shown thatthis deviation in assembly procedure may have occurred inunits manufactured from March, 1989 until September, 1990.Each relay is marked in the upper right corner of thelegend plate with the year and week of manufacture (e.g.9036). The relays that may have this problem are the typeRXMH2 marked 8909 up to and including 9036.Field data does not indicate a reliability problem withthis component. However, ABB is aware of application ofthe RXMH2 auxiliary relays in protection and controlsystems 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 coilinsulation 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. allaceManager Total Quality &Proce Technology v,.Reviewed By: Date: 4 .onald L. Jan \\-Vice President &General ManagerWHW/lwcc: Michael Charlton/United ControlsS. Franzone/FP&L91BW160 Attachment 2IN 92-05January 8, 1992 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to92-0492-0392-0292-0191-8791-86Potter & Brumfield ModelMDR Rotary Relay FailuresRemote Trip FunctionFailures in General ElectricF-Frame Molded-Case CircuitBreakersRelap5/Mod3 Computer CodeError Associated with theConservation of EnergyEquationCable Damage Caused byInadequate Cable Installa-tion Procedures and ControlsHydrogen Embrittlement ofRaychem Cryofit CouplingsNew Reporting Requirementsfor Contamination Events atMedical Facilities(10 CFR 30.50)Potential Failures ofThermostatic Control Valvesfor Diesel Generator JacketCooling WaterProblems with CriticalityAlarm Components/SystemsSolenoid-Operated ValveFailures Resulted inTurbine Overspeed01/06/9201/06/9201/03/9201/03/9212/27/9112/27/9112/26/9112/26/9112/20/91All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All licensees authorizedto use byproduct materialsfor human use.All holders of OLs or CPsfor nuclear power reactors.All Nuclear RegulatoryCommission (NRC) fuelcycle licensees, interimspent fuel storage licens-ees, and critical masslicensees.All holders of OLs or CPsfor nuclear power reactors.91-8591-8491-83OL = Operating LicenseCP = Construction Permit IN 92-05January 8, 1992 process, the tape had been pulled back and dislocated away from the beginninglead it was supposed to hold in the end flange channel of the coil spool. Someof the varnish insulation on the beginning lead was then apparently abradedduring the winding process, allowing the insulation breakdown which caused therelay to fail.ABB inspected other relays, none of which had yet failed, to determine if theseparation tape was adequately placed. The acceptance criterion established byABB specified that the separation tape must cover the beginning lead with anoverlap margin of 1.0 millimeter (mm) or greater. Although none of the relayshad damaged or dislocated separation tape, ABB found that almost all of themhad less than 1.0 mm of margin.United Controls and ABB determined that the problem had generic implicationsbut that the scope was limited to relays with the particular coil design inquestion (type RXMH2, Models RK223068-EA and RK223069-EA) manufactured fromMarch 1989 through September 1990. ABB identified the root cause of theproblem as the performance of one factory employee who had manufactured relayswithin the date codes cited above.ABB has made a design change to reposition the separation tape on the endflange of the coil spool to more evenly cover the beginning lead and avoidconditions that could cause the separation tape to be dislocated during thewinding process. ABB has also taken action to ensure that all pertinent draw-ings and procedures have been updated and corrected and that all affectedemployees have been trained on the changes.The manufacturer, ABB, did not believe that field data indicated a reliabilityproblem with the type RXMH2 relay but recommended that in applications in whicha failure to operate could cause a substantial safety hazard, the relays bechecked for coil insulation integrity.The RXMH2 relays having the potential fortured from March 1989 to September 1990.right corner of the legend plate with thedates of concern indicated as 8909 up to,insulation breakdown were manufac-The relays are marked in the upperyear and week of manufacture; theand including, 9036.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate Office of Nuclear ReactorRegulation (NRR) project manager.Original Sign~df 5Charie EL M'Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact:Bill Rogers, NRR(301) 504-2986

Attachments:

1. ABB 10 CFR Part 21 Notification to the NRC2. List of Recently Issued NRC Information Notices*SEE PREVIOUS CONCURRENCES Document Name: IN 92-05DRIS:VIB DRIS:VIB DRIS:VIB DRIS:VIBBROGERS CVANDENBURGH LNORRHOLM BGRIMESON4* A 1 .12/12/91* 12/16/91*CBERLINGER12/27/91* 2_TECH ED :JMAIN :12/10/91*

IN 91-XXDecember XX, 1991 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contact thetechnical contact listed below or the appropriate Office of Nuclear ReactorRegulation (NRR) project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Bill Rogers, NRR(301) 504-?986

Attachments:

1. ABB 10 CFR Part 21 Notification to the NRC2. List of Recently Issued NRC Information Notices*See previous concurrencesOFC :DRIS:VIB :DRIS:VIR :DRIS:VIB :DRIS:VIB :TECH EDNAME :BROGERS :CVANDElBURGH :LNORRHOLM :BGRIMES :JMAINDATE :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 :CROSSIDATE :12/7/91 :12/ /91OFFICIAL RECORDDocument Name: ABB RELAY INFO NOTICE IN 91-XXDecember xx, 1991 year and week of manufacture, the dates of concern indicated as8909 up to, and including 9036.This information notice requires no specific action or writtenresponse. If you have any questions about the information inthis notice, please contact the technical contact listed below orthe appropriate Office of Nuclear Reactor Regulation (NRR)project manager.Charles E. Rossi, DirectorDivision of Operational EventsAssessmentOffice of Nuclear Reactor RegulationTechnical Conta

Attachment:

Lct:Bill Rogers, NRR(301) 492-0986List of Recently Issued NRC Info ion Noticesconcurrences*See previous cIOFFICE NRR:OGCB NRR:DOEANAME CBERLINGER CROSSIIDATE 12/ /91 12/ /91OFFICIAL RECORD COPYWORDPERFECT DOCUMENT NAME:ABBRELAY.IN This information notice requires no specific action or writtenresponse. If you have any questions about the information inthis notice, please contact the technical contact listed below orthe appropriate Office of Nuclear Reactor Regulation projectmanager.Charles E. Rossi, DirectorDivision of Operational EventsAssessmentOffice of Nuclear Reactor Regulation

Technical Contact:

Bill Rogers, NRR(301) 492-0986

Attachments:

1. List of Recently Issued NRC Information NoticesIi I I I I I IIIOFFICEI DRIS:VIB IDRIS:VIB JDRIS:VIB I DRIS:DD I TECHED flII Ii I i I !IflNAME IBROGERS ICVANDENBURGHjLNORRHOLMI BGRIMES I gIN fllIDATE l 12/ /91 l 12/ /91 112/ /91 l 12/ /91 l 12/10 /91 llII I I I IIIi I I iIIOFFICE1 NRR:OGCB I NRR:DOEA llIi 1 I 11lINAME ICBERLINGERI CROSSI I11 1 1 11lIDATE I 12/ /91 l 12/ /91 llpl I I I