Deck 11: Operation of Three-Phase Alternators

Question 1

In industrial applications, alternators are driven by various types of ____________________.

Answer 1

prime movers

Question 2

When two alternators are in step, they are said to be in ____________________.

Answer 2

synchronism

Question 3

When paralleling alternators, set the field rheostat (R₂) of alternator G₂ to the minimum resistance position.

Answer 3

False

Question 4

What values must be nearly equal before alternators can be paralleled?

Question 5

For applications on ships, alternators are often driven by DC motors.

Question 6

In the two bright, one dark method, any two connections from the synchronizing lamps are crossed after the alternators are connected and tested for proper ____________________.

Question 7

A(n) ____________________ is recommended for synchronizing two alternators.

Question 8

Where is reverse power a situation of particular concern?

Question 9

How can you check that the phase rotation of both AC generators being synchronized is the same?

Question 10

Two alternators are paralleled whenever the power demand of the load circuit is less than the power output of a single alternator.

Question 11

In practice, the ____________________ of the incoming generator is 1 to 2 Hz higher than that of the on-line generator.

Question 12

What occurs if one alternator attempts to pull out of synchronism?

Question 13

How does a generator act as a motor running at no load?

Question 14

In practice, the voltage of the incoming generator is usually slightly higher than that of the other operating generator.

Question 15

The two bright, one dark method of synchronizing alternators has certain disadvantages and is seldom used.