United States Nuclear Regulatory Commission - Protecting People and the Environment

General Information or Other Event Number: 38920
REP ORG: SOLID STATE CONTROLS, INC NOTIFICATION DATE: 05/15/2002
SUPPLIER: SOLID STATE CONTROLS, INC NOTIFICATION TIME: 15:07 [EDT]
CITY: COLUMBUS REGION: 3 EVENT DATE: 04/15/2002
COUNTY: STATE: OH EVENT TIME: [EST]
LICENSE#: AGREEMENT: Y LAST UPDATE DATE: 05/15/2002
DOCKET: PERSON ORGANIZATION
RONALD GARDNER R3
   
   
NRC NOTIFIED BY: W. G. HAMPTON (FAX)    
HQ OPS OFFICER: MIKE NORRIS    
EMERGENCY CLASS: NON EMERGENCY
10 CFR SECTION:
CCCC 21.21 UNSPECIFIED PARAGRAPH

EVENT TEXT

10 CFR 21 NOTIFICATION-POTENTIAL DEFECT INVOLVING FAN ASSEMBLIES FOR UPS SYSTEMS

"The attached 10 CFR Part 21 record, Attachment A, is submitted to report a potential for a defect in fan assemblies used in Uninterruptible Power Systems manufactured under the Solidstate Controls, Inc., 10CFR50 Appendix B Program.

"Nature of the defect:

"PROBLEM SEEN: The above assembly contains a component part - an aluminum, five-wing fan blade, which potentially could separate from the hub. If the blade should come loose there may not be an alarm indication of loss of cooling. Additionally, the loose blade may cause a short circuit if it falls into the equipment and should land across opposing current carrying devices.

"CAUSE: We have determined that one fan blade style from one specific manufacturer of part number 03-470100-00 could, under certain conditions, separate from its hub.

"EFFECT ON SYSTEM PERFORMANCE: Fan Assembly - THE SEPARATION OF THE BLADE FROM THE HUB COULD CAUSE THE SYSTEM TO DROP POWER TO THE LOAD. If the worst case failure mode described above were to occur, it would result in the motor continuing to operate, thereby, not allowing the internal alarm mechanism to activate. Further, the blade itself could fall into the operating equipment causing a short circuit. It is important to note that the short circuit situation has not been reported.

"US NUCLEAR PLANT IMPACTED BY THIS ACTION: There are approximately 30 plants listed"

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