Operate Alternators, Generators. Test 7

A current clamp meter is clipped around a cable supplying a balanced three phase motor working at full load. The motor is rated to consume 100 A. What will the meter show ?

100 Amps.
0 Amps.
110 Amps.
33.3 Amps.

How can you monitor the correct instant for synchronising alternators should your synchronising system (synchronoscope or lamps) be defective ?

By fitting a voltmeter over one phase.
By fitting lamps over the three phases.
By fitting lamps crossed over two phases.
By fitting two voltmeters crossed over two phases.

What possibilities exist to supply power via direct connection to the Emergency Switchboard.

1) Supply by main diesel engines. 2) Supply by emergency diesel.
1) Supply by main switchboard. 2) Supply by emergency diesel.
1) Supply by shore power. 2) Supply by main switchboard.
1) Supply by shore power. 2) Supply by main switchboard.

A split-phase motor is an induction motor where the magnetic fields are produced by _____ that causes the motor to rotate.

the shunt and the series windings
two permanent magnets
the three stator windings
the main and the auxiliary windings

How is the direction of rotation changed in an asynchronous motor?

By reversing the frequency.
By switching two of the three connections on the motor terminal.
By switching all three connections on the motor terminal.
The direction of rotation cannot be changed.

Three motors with full load currents of 15, 40 and 52 Amps each are fed by an unidentified feeder. What is the minimum size of the motor feeder current carrying capacity ?

Approx 235 Amps.
Approx 175 Amps.
Approx 134 Amps.
Approx 350 Amps.

What should be the minimum current carrying capacity of branch circuit conductors supplying a single motor ?

200 % of the full motor name plate rating.
140 % of the full motor name plate rating.
110 % of the full motor name plate rating.
125 % of the full laoad current name plate rating.

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