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單項(xiàng)選擇題

When two DC generators operate in parallel, they are protected against motorizing by（）

A.blow out coils
B.governor relay
C.under voltage trips
D.reverse current trips

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單項(xiàng)選擇題

The correct phase rotation of a three-phase alternator can be checked with a（）

A.dynamometer
B.power factor meter
C.three-phase motor
D.polyphase voltmeter

單項(xiàng)選擇題

A probable cause for a turbo generator tripping out on overspeed is a sudden（）

A.loss of field excitation
B.total loss of load
C.large increase in load
D.loss of steam pressure

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