3 Phase Motors And Starters

Question 1

Windings are connected in (series / parallel) for LOW voltage operations

Answer 1

Parallel

Question 2

Dual voltage motors are designed to operate on either 240V or 480V systems.

True or False

Answer 2

True

Question 3

Windings are connected in (series / parallel) for HIGH voltage operations

Answer 3

Series

Question 4

How many leads are there on a single phase motor?

Answer 4

Six leads

T1 and T4
T2 and T5
T3 and T6

Question 5

Motor Starters can be

a) Across-the-line starters
b) Reduced-voltage starters
c) both a and b

Answer 5

c) both a and b

Question 6

Across-the-line starters apply (full / reduced) voltage to the motor at start

Answer 6

Across-the-line starters apply FULL voltage to the motor at start

Question 7

Reduced-voltage provide a (full / reduced) voltage at start and (full / reduced) voltage at run.

Answer 7

Reduced-voltage provide a REDUCED voltage at start and FULL voltage at run.

Question 8

Full-Voltage manual and magnetic starters apply (full / reduced) voltage to the motor at the instant of start. The initial starting current is between ____% and _____% of full load current and a starting torque that is about _____% of full load torque.

Answer 8

Full-Voltage manual and magnetic starters apply FULL voltage to the motor at the instant of start. The initial starting current is between 500% and 600% of full load current and a starting torque that is about 150% of full load torque.