Deck 23: Across-The-Line Starting

Question 1

Direct current motors depend on inductive reactance to limit current flow.

Answer 1

False

Question 2

In a DC contactor with two coils, the ____________________ coil is intended for momentary duty and not continuous operation.

Answer 2

pick-up,pick up

Question 3

What do direct current starters and contactors that do not utilize arc suppressors or magnetic blowout coils use to break the circuit?

Answer 3

Direct current starters and contactors that do not utilize arc suppressors or magnetic blowout coils often use multiple contacts to break the circuit. Connecting contacts in series gives the contactor the ability to break higher voltages.

Question 4

In a grounded system, the current sensing device must be in the ____________________ conductor.

Question 5

Direct current motors require only one ____________________ contact to connect or disconnect them to the power line and one overload sensing device.

Question 6

How is across-the-line starting accomplished?

Question 7

Some DC contactors contain two separate coils. Describe the two coils.

Question 8

Across-the-line starting is the simplest of all starting methods.

Question 9

In-rush current is referred to a(n) ____________________ current.

Question 10

Why is it that small DC motors can be started across-the-line?

Question 11

Across-the-line starting is only used for alternating current.

Question 12

The type of rotor is identified by a code letter on the ____________________ of a motor.

Question 13

Contactors intended to connect direct current motors to the line often have arc suppression and magnetic blowout coils.

Question 14

The type of bars used to construct the rotor has a great effect on the operating characteristics of the motor.

Question 15

In direct current motors, by what is the initial in-rush current limited?