Deck 9: Forward-Reverse Control

Question 1

Figure 9-3
The accompanying figure shows a vertical ____________________ starter with overload relay.

Answer 1

reversing

Question 2

How can the direction of rotation of any three phase motors be reversed?

Answer 2

The direction of rotation of any three phase motors can be reversed by changing any two motor T leads.

Question 3

What would happen if both contactors were energized at the same time?

Answer 3

Having both contactors energized would result in two of the three phase lines being shorted together.

Question 4

How is mechanical interlocking accomplished?

Question 5

How are mechanical interlocks shown in a schematic diagram?

Question 6

The motor is connected to the power line regardless of which direction it operates.

Question 7

What does interlocking do?

Question 8

If R coil energizes, all R contacts change position.

Question 9

Figure 9-6
In the accompanying figure, the dashed lines drawn between the push buttons indicate that they are ____________________ connected.

Question 10

Magnetic reversing starters generally change T leads ____________________ and ____________________ to reverse the motor.

Question 11

One of the methods of electrical interlocking is accomplished with the use of double-acting push buttons.

Question 12

Figure 9-12
The accompanying figure shows the components needed to construct a(n) ____________________ control circuit.

Question 13

Four methods of electrical interlocking are available.

Question 14

Electrical interlocking can be accomplished by connecting the normally closed ____________________ contacts on one contactor in series with the coil of the other contactor.

Question 15

Most reversing controllers only contain mechanical interlocks.