Deck 26: Wye-Delta Starting

Question 1

If the stator windings of a motor are connected in delta during the starting period, the starting current will be ____________________ times the value if the windings were connected in wye.

Answer 1

three
3

Question 2

Figure 26-9
What does the accompanying diagram show?

Answer 2

The figure shows a basic control circuit for wye-delta starter using time delay. This circuit employs time delay to determine when the windings will change from wye to delta.

Question 3

Open transition starting means that the motor is connected to the power line during the transition from wye to delta.

Answer 3

False

Question 4

Dual voltage motors not intended for wye-delta connection will have certain terminals tied internally.

Question 5

How is wye-delta starting accomplished?

Question 6

Wye-delta starting is sometimes called ____________________ starting.

Question 7

Wye-delta starting is often used with large horsepower motors to reduce in-rush current during the starting period and reduce starting ____________________.

Question 8

Figure 26-9
What is the most critical part of connecting a wye-delta starter?

Question 9

Closed transition starting does not disconnect the motor from the power line.

Question 10

In a wye connection, the line current and phase current are not the same.

Question 11

Motors that are intended to operate on two voltages such as 240 or 480 volts contain two separate ____________________ of each phase.

Question 12

Figure 26-1
What are the two requirements that must be met before wye-delta starting can be used?

Question 13

Dual voltage motors designed for wye-delta starting will supply all 12 T leads at the terminal connection box.

Question 14

If the stator windings are connected in ____________________, the voltage across each phase will be 480 volts because line voltage and phase voltage are the same in a(n) ____________________ connection.

Question 15

Figure 26-1
What does the accompanying figure show?