ENS Event | |
|---|---|
04:00 Jun 1, 2015 | |
| Title | Part 21 - Defective Circuit Breaker Secondary Close Latch |
| Event Description | The following is an excerpt of communication received via email:
This letter provides notification of a failure to comply with specifications associated with a secondary close latch, part number 716610K01, used in K-Line 225/800 and 1600/2000 amp electrically operated Model 7 circuit breakers. Nature of the deviation: During installation of a primary close latch and subsequent bench testing at a nuclear utility, mechanical binding was observed between the primary and secondary close latches. This binding prevented the breaker from operating. Inspection of both latches by ABB showed that the issue lies with the secondary close latch. It was determined that the secondary close latch dimension from the centerline of the hub that the latch rotates about, to the edge of the secondary latch surface with the half pin on the primary latch, was oversized. The failure to comply was identified when replacing latches and verified with a calculated dimension. The additional length from the center of the hub in the secondary close latch to the corner of the latch surface caused an interference between the pin cam interface and the half pin on the primary close latch, where it rolls off of the latch surface on the secondary close latch. It is recommended that affected licensees with this latch in inventory, ensure that bench testing is performed prior to installation to verify that the primary and secondary close latches work together without any evidence of binding. ABB currently cycles K-Line breakers that are refurbished approximately 55 close/open operations before they ship from the Florence facility. New breakers get at least the same number of close/open operations before shipment. This level of operational testing validates that there is no binding between the primary and secondary close latches. Questions concerning this notification should be directed to the Quality Manager at the Medium Voltage Service Center in Florence, SC at (843) 413-4727 or Fax (843) 413-4853. |
| Where | |
|---|---|
| Asea Brown Boveri Florence, South Carolina (NRC Region 1) | |
| Organization: | Abb Medium Voltage Service |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+6.5 h0.271 days <br />0.0387 weeks <br />0.0089 months <br />) | |
| Opened: | Jay Lavrinc 10:30 Jun 1, 2015 |
| NRC Officer: | Daniel Mills |
| Last Updated: | Jun 1, 2015 |
| 51109 - NRC Website | |
Asea Brown Boveri with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 511092015-06-01T04:00:0001 June 2015 04:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Defective Circuit Breaker Secondary Close Latch 2015-06-01T04:00:00 | |