View source for Information Notice 1992-03, Remote Trip Function Failures in General Electric F-Frame Molded-Case Circuit Breakers

{{Adams
| number = ML031200762
| issue date = 01/06/1992
| title = Remote Trip Function Failures in General Electric F-Frame Molded-Case Circuit Breakers
| author name = Rossi C E
| author affiliation = NRC/NRR
| addressee name = 
| addressee affiliation = 
| docket = 05000003, 05000010, 05000029, 05000133, 05000155, 05000171, 05000206, 05000213, 05000219, 05000220, 05000237, 05000244, 05000245, 05000247, 05000249, 05000250, 05000251, 05000254, 05000255, 05000259, 05000260, 05000261, 05000263, 05000265, 05000266, 05000267, 05000269, 05000270, 05000271, 05000272, 05000275, 05000277, 05000278, 05000280, 05000281, 05000282, 05000285, 05000286, 05000287, 05000289, 05000293, 05000295, 05000296, 05000298, 05000301, 05000302, 05000304, 05000305, 05000306, 05000309, 05000311, 05000312, 05000313, 05000315, 05000316, 05000317, 05000318, 05000320, 05000321, 05000322, 05000323, 05000324, 05000325, 05000327, 05000328, 05000329, 05000330, 05000331, 05000333, 05000334, 05000335, 05000336, 05000338, 05000339, 05000341, 05000344, 05000346, 05000348, 05000352, 05000353, 05000354, 05000361, 05000362, 05000364, 05000366, 05000368, 05000369, 05000370, 05000373, 05000374, 05000382, 05000387, 05000388, 05000389, 05000390, 05000391, 05000395, 05000397, 05000400, 05000409, 05000410, 05000412, 05000413, 05000414, 05000416, 05000423, 05000424, 05000425, 05000437, 05000438, 05000439, 05000440, 05000441, 05000443, 05000444, 05000445, 05000446, 05000454, 05000455, 05000456, 05000457, 05000458, 05000461, 05000482, 05000483, 05000498, 05000499, 05000508, 05000528, 05000529, 05000530
| license number = 
| contact person = 
| document report number = IN-92-003, NUDOCS 9112300071
| document type = NRC Information Notice
| page count = 10
| revision = 0
}}
{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555January 6, 1992NRC INFORMATION NOTICE 92-03: REMOTE TRIP FUNCTION FAILURES IN GENERALELECTRIC F-FRAME MOLDED-CASE CIRCUITBREAKERS

==Addressees==
All holders of operating licenses or construction permits for nuclearpower reactors.

==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information noticeto alert addressees to a potentially safety-significant problem resulting fromthe possible failure of the remote trip functions of General Electric (GE)F-frame (225-ampere frame size) molded-case circuit breakers (MCCBs). 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 November 5, 1991, GE Nuclear Energy (GE NE), San Jose, California, issued aninterim notification of its evaluation of a deviation in accordance with thelatest revision (effective October 29, 1991) of Part 21, "Reporting of Defectsand Noncompliance," of Title 10 of the Code of Federal Regulations(10 CFR Part 21). The notification described the deviation as a "tolerancebuildup" in certain GE F-frame MCCBs with undervoltage releases (UVRs) andshunt trip devices (STs) that may inhibit these internal accessory remote tripdevices from functioning properly under conditions that produce sustained highinternal temperatures in the MCCBs.The attachment to the GE NE notification was taken from a draft Service AdviceLetter (SAL) on this subject being prepared by the MCCB manufacturer, GEElectrical Distribution and Control (ED&C), in Plainville, Connecticut.GE NE plans to send the 10 CFR Part 21 interim notification to all of itscustomers who have purchased F-frame MCCBs for safety-related applicationsand to all GE NE Material Services field representatives. GE ED&C plans tosend the SAL (issued November 25, 1991 as SAL 91-2F) to all of its customers ofrecord, many of whom are distributors. However, both the F-frame MCCBs andtheir accessory trip devices are available on the open market as commercialgrade items through various distribution paths. Therefore, the licensees forsome nuclear plants who use these MCCBs may not receive the GE notifications.-e 7* '-923/ _ // 7#c IN 92-03January 6, 1992 DiscussionAlthough still evaluating the problem, the MCCB manufacturer has determinedthat assembly and operational variations caused the reported failures. Thevariations reportedly resulted from (1) tolerances in mounting the accessorytrip devices in the MCCBs, (2) tolerances on the adjustment of the ambientcompensating bimetal (part of the thermal overload trip mechanism), and (3)sustained high operating temperatures in the MCCBs. The high internal temper-ature in the MCCB required to produce a condition conducive to the malfunctioncan result from continuous high current load (greater than 50 percent of theovercurrent trip unit rating for more than 2 hours) together with a highambient temperature in the enclosure. A secondary heat source could alsoproduce the high temperatures required for this malfunction.GE NE stated in its interim notification that UYR- and ST-equipped MCCBsproduced after April 1991 (date codes J116= and 1116=) incorporated changesthat would prevent this condition. GE NE also stated that an MCCB may or maynot exhibit this malfunction, depending on the particular circumstancesassociated with the assembly of the breaker and the accessory remote tripdevices, in conjunction with the high temperature service conditions believed tobe conducive to failure. Nevertheless, GE NE maintained that affected MCCBswill trip under overcurrent conditions and will trip remotely at the lower MCCBinternal temperatures usually present with lower load currents and enclosureambient temperatures or without secondary heat sources.GE NE initially reported that it had identified a. specific safety-relatedapplication for the affected F-frame MCCBs equipped with internal accessoryremote trip devices. The identified application is associated with themultiple electrical protection assemblies (EPAs) used in boiling water reactor(BWR) plants to monitor power quality to the reactor protection system (RPS).The EPAs trip the F-frame breakers for the RPS power supplies by means of theremote trip devices if the EPAs detect overvoltage, undervoltage, or underfre-quency conditions in RPS power. In addition, GE NE informed the NRC in asubsequent communication that it may also have supplied some of the affectedMCCBs as part of subassembly-level applications not separately identified inGE NE records. The affected MCCBs fitted with factory-installed remote tripaccessories may also be used in numerous other applications in all types ofnuclear plants in which remote tripping of an F-frame MCCB by means of the UVRor ST may be a safety-related function.The presence of UVRs or STs in F-frame MCCBs should be apparent when the unitsare installed in the plant. However, even if accessory designation markingsare not evident, affected MCCBs can be recognized by the two UVR or ST leadwires protruding through small openings in the sides of the MCCB case.Additionally, UVRs set up for monitoring 240, 480, or 600 volts-AC or 250volts-DC should have an external dropping resistor connected in series with oneof their lead wires. Attachment 1 lists the breaker frame type designations of IN 92-03January 6, 1992 the potentially affected MCCBs and the catalog numbers of the affectedinternal accessory remote trip devices and also gives the date codes of theunits believed by the manufacturer to be affected.In view of the potentially wide scope of application of the affectedMCCBs, addressees may find the affected types of UVR- and ST-equipped MCCBsboth installed and in the warehouse.

==Addressees==
who find any affected MCCBsmay consult the manufacturer on this subject to determine the appropriatecorrective action, including testing for the existence of the malfunction,analyzing the potential high temperature producing conditions, or replacingthe affected components.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactthe technical contact listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.I.1os i S DoirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact: S. D. Alexander, NRR(301) 504-2995

===Attachments:===
1. Affected MCCBs and Accessories2. List of Recently Issued NRC Information Notices Attachment 1IN 92-03January 6, 1992 AFFECTED MCCBs and ACCESSORIESThe affected GE F-frame ("F-225 Line") MCCBs include the breaker types orframes listed below which can be fitted with any of the accessory remote tripdevices with the listed catalog numbers:BREAKER FRAMES SHUNT TRIPS UNDERVOLTAGE RELEASESTFK, THFK TFKSTA12 TFKUVA1TFJ TFKSTA13 TFKUVA2THLC2 TFKSTA7 TFKUVA4THLB2 TFKSTA8 TFKUVA6THLC4 TFKSTA9 TFKUVA7TLB4 TFKSTA11 TFKUYA8TFKUVA9TFKUVA10TFKUVA11According to GE NE and GE ED&C, the tolerance buildup affects F-frame MCCBs andUYRs and STs assembled between August 1979 and April 1991 (accessory date codesN927* through N116=). The potentially affected MCCBs could have manufacturingdate codes J927* through J116= (1116= for current limiting frames), but ED&Creported no identifiable volume of field returns for this condition among MCCBsbuilt before the fourth quarter of 1987 (breaker date codes J736+ and I736+).The accessory date code is its manufacturing date code and only appears on theaccessory itself. However, the date code from the accessory installationfacility may appear on the MCCB case in addition to the manufacturing date codeof the MCC Attachment 2IN 92-03January 6, 1992 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to92-0292-0191-8791-8691-8591-8491-83Relap5/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 OverspeedHigh-Energy Piping FailuresCaused by Wall ThinningProblems with Diaphragmsin Safety-Related Tanks01/03/9201/03/9212/27/9112/27/9112/26/9112/26/9112/20/9112/18/9112/18/91All 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 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.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.91-18,Supp. 191-82OL = Operating LicenseCP = Construction Permit IN 91-XXDecember XX,  Document Name: GE FFRAME MCCB INFO NOTICE IN 92-03January 6, 1992 the potentially affected MCCBs and the catalog numbers of the affectedinternal accessory remote trip devices and also gives the date codes of theunits believed by the manufacturer to be affected.In view of the potentially wide scope of application of the affectedMCCBs, addressees may find the affected types of UVR- and ST-equipped MCCBsboth installed and in the warehouse.

==Addressees==
who find any affected MCCBsmay consult the manufacturer on this subject to determine the appropriatecorrective action, including testing for the existence of the malfunction,analyzing the potential high temperature producing conditions, or replacingthe affected components.This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactthe technical contact listed below or the appropriate Office of NuclearReactor Regulation (NRR) project manager.original Signed byCharles E. RossiCharles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact: S. D. Alexander, NRR(301) 504-2995

===Attachments:===
1. Affected MCCBs and Accessories2. List of Recently Issued NRC Information Notices* see previous concurrencesOFC :VIB/DRIS :YIB/DRIS :VIB/DRIS :TECH ED :D:DRISNAME :SAlexander:sda :CVanDenburgh :LNorrholm :JMain :BKGrimesDATE :12/19/91* :12/4/91* :12/19/91* :12/4/91* :12/19/91*OFC :BC:GCB:DOEA :DD:D0EANAME :CBerlinger : oRJ O : : :DATE :12/20/91* :12/tW91 : : :OFFICIAL RECORD COPY Document Name: IN 92-03 IN 91-XXDecember XX, 1991Pace 3 of 3the potentially affected MCCBs and the catalog numbers of the affected internalaccessory remote trip devices and also gives the date codes of the unitsbelieved by the manufacturer to be affected.In view of the potentially wider scope of the application of the affectedMCCBs, addressees may find the affected types of UVR- and ST-equipped MCCBsboth installed and in the warehouse.

==Addressees==
who find any affected MCCBsmay consult the manufacturer on this subject to determine the appropriatecorrective action, including testing to confirm the existence of the malfunc-tion, analyzing the potential high temperature producing conditions, orreplacing the affected components.No specific action or written response is required by this notice. If youhave any questions regarding this notice, please call the technical contactlisted below, or the appropriate Office of Nuclear Reactor Regulation (NRR)project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

===Technical Contact:===
S. D. Alexander, NRR(301) vq-0995Attachment 1: Affected MCCBs and AccessoriesAttachment 2: List of Recently Issued NRC Information NoticesDISTRIBUTION:Central Files PDR DRIS R/F VIB R/FSAlexander CVanDenburgh LNorrholm BGrimesCBerlinger ERossi* see previous concurrencesOFC :VIB/DRIS VIB/DRIS :VIB IS :TECH ED___-_--_---_-_- l----- ---------.---f-- ------- -------------- -- iv- ------- --------------NAME :5Alexander:sda: CVanDenburgh :L L Wm :JMain sDATE :12 4J9 1 :12/4/91* :12A9/91 :12/4/91* :12/11 /91 CA"OFC :BC:.BDOEA :DD:DOEA : ' :NAME C erlinger :CERossi : :DATE --- ------ :-------1/----_ ___________:______________ -------------- -------------DATE :12/,vO/91 :121 /9-1 ::OFFICIAL RECORD COPY Document Name: DRAFT GE INFO MCCB NOTICE IN 91-XXDecember XX, 1991 Document Name: GER2.IN IN 91-XXDecember XX, 1991 No specific action or written response is required by thisnotice. If you have any questions regarding this notice, pleasecall the technical contact listed below, or the appropriateOffice of Nuclear Reactor Regulation project manager.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation

===Technical Contact:===
S. D. Alexander, NRR(301) 492-0995Attachment 1:Frame Types and Date Codes of Affected MCCBs andCatalog Numbers and Date Codes of Affected Acces-soriesAttachment 2: List of Recently Issued NRC Information NoticesDISTRIBUTION:Central FilesSAlexanderCBerlingerPDRCVanDenburghERossiDRIS R/FLNorrholmVIB R/FBGrimesOFFICE DRIS:VIB DRIS:VIB DRIS:VIB TECH ED DRIS:DDNAME ACVAN GH LNORRHOLM JMAIN 9T% BGRIMESDATE 12/ LJ/91 12/1 /91 12/ /91 12/ Y/91 12/ /91OFFICE DOEA:GCB DOEA:DDNAME CBERLINGER EROSSIDATE 12/ /91 12/ /91}}

{{Information notice-Nav}}