Exam 18: Ac Generators Alternators

The phase sequence describes the order in which the currents follow one another.

Frequency is calculated by taking the number of field poles on the alternator, multiplying by ____, and then dividing their product by 120.

The prime mover in a motor-generator set is the _____.

What instrument is used to determine whether the frequency of an alternator to be brought on line matches the frequency of the bus?

The standard frequency for power distribution in the U.S. is 120 Hz.

Direct current is less expensive to produce and transmit than alternating current.

The wye connection, sometimes called a star connection, is a method of connecting coils together inside the alternator.

Another name for a rotary converter is a(n) _____.

What is one factor that affects the output voltage of an alternator?

The rotating field of a large alternator receives its energy from the DC exciter, through slip rings.

The ____ method for synchronizing alternators is generally used only for small operations or for laboratory experiments.

In a balanced three-phase system, the power factor is the____ of the angle between the phase current and the phase voltage.

In a wye-connected alternator, the line voltage is equal to ____ times the phase voltage.

When alternators are connected in parallel, the phase rotation of the alternator and the distribution bus must be ____.

In a delta-connected alternator, the line voltage is equal to ____ times the phase voltage.