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Does a circuit breaker close if the UVR (MN) is not energized?

FA89487

23 January 2021

Issue:
Does a circuit breaker close if the UVR (MN) is not energized?

Product Line:
Masterpact, Powerpact, Legacy Circuit Breakers

Environment:
UVR not energized.


Resolution:
No. This release instantaneously opens the circuit breaker when the supply voltage drops below a value between 35% and 70% of rated voltage. If the release is not energized, the circuit breaker cannot be closed (either manually or electrically). Any attempt to close it will have no effect on the main contacts. Closing is possible when the release voltage reaches 85% of its rated value.