Deck 24: Resistor and Reactor Starting for Ac Motors

Question 1

Figure 24-1

The accompanying diagram uses ____________________ to shunt the resistors out of the circuit after some period of time.

Answer 1

time delay

Question 2

In a resistive circuit, the current will take some time to reach its full Ohm's law value.

Answer 2

False

Question 3

What are two of the most common methods of reducing the amount of starting current?

Answer 3

Resistor starting and reactor starting are the two methods.

Question 4

One way of determining when to shunt the resistors out of the circuit is by sensing motor current.

Question 5

In an inductive circuit, the current must rise at an exponential rate.

Question 6

Why is time delay one of the most popular methods of determining when to connect the motor directly to the power line?

Question 7

Current ____________________ are used to sense the amount of motor current.

Question 8

Some control circuits sense ____________________ speed to determine when to shunt the resistors out of the power line.

Question 9

____________________ is accomplished by connecting resistors in series with the motor during the starting period.

Question 10

Resistors connected in series with the motor limit the amount of in-rush current.

Question 11

Name two conditions where it is not possible to start a motor across-the-line.

Question 12

Some resistor and reactor starters use multiple steps of starting. How is this accomplished?

Question 13

Figure 24-4

In the circuit shown in the accompanying figure, the current sensor contacts are normally open.

Question 14

Reactors limit in-rush current with ____________________ instead of resistance.

Question 15

Figure 24-1

In the accompanying figure, what happens right after the START button is pressed?