Given the following indications for an open 4,160 VAC breaker:
The local OPEN/CLOSED mechanical flag indicates OPEN.
A breaker overcurrent trip flag is actuated on one phase.
The line-side voltmeter indicates 4,160 VAC.
The load-side voltmeter indicates 0 VAC.
Assuming no operator actions were taken since the breaker opened, which one of the following could have caused the breaker to open?
A. A ground fault caused an automatic breaker trip.
B. A loss of control power caused an automatic breaker trip.
C. An operator opened the breaker locally.
D. An operator opened the breaker from a remote location.
Show Answer
Answer: A
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