Mississauga, ON — Schneider Electric has identified a potential non-conformance issue with the bus mounting hardware used with its Square D Masterpact NW Circuit Breakers (800 Amp to 6300 Amp) assembled in North America. This also applies to equipment using these circuit breakers, such as PZ-4, QED-6, QED-2, QEDS, and Model 6 MCC.
These circuit breakers may have a non-conforming washer on primary terminal mounting screws. If the washer is non-conforming, there is a risk of low clamp force between the terminal and the breaker/cradle. This can result in overheating at the loose connection. Should this occur there is a potential for property damage, or that the circuit breaker may not operate as intended.
We have identified a process non-conformance from our supplier, within the manufacturing period from March 1, 2012 through June 12, 2012 (Date Codes 12094–12242 inclusive) as the root cause of the potential problem.
Recommended actions for users
Contact Schneider Electric Services, Product Support Services, at 1-800-634-8730 or 704-571-6020 if you have any questions. Please refer to Project RC103 when calling. The company will send you one or more questionnaires. This information provided is critical to insure that the correct contact information is obtained for the update activity. Upon receipt of the completed questionnaire, Schneider Electric will contact you to schedule a date and time when your Masterpact circuit breakers can be updated. Complete de-energization of the circuit breaker/equipment will be required. Important Note: You must have someone qualified on site at the time of the update to shutdown and re-energize your equipment.
Since there is no way to visually inspect the product for the non-conformance, if the circuit breaker is energized, it is recommended that you use thermal scans to check for overheating at the buss connections to the cradle or back of the circuit breaker.
Minimize loading as much as possible and monitor the circuit breaker and equipment for overheating until such time as the equipment can be repaired.