Deck 12: Sequence Control

Question 1

Sequence control can be achieved by several methods.

Answer 1

True

Question 2

What kinds of machines use sequence control? Give at least one example.

Answer 2

Sequence control is used by such machines as hydraulic presses that must have a high pressure pump operating before they can be used, or by air conditioning systems that require that the blower be in operation before the compressor starts.

Question 3

Circuits that permit the automatic starting of motors in sequence are rare.

Answer 3

False

Question 4

Figure 12-2

In the circuit shown in the figure above, what prevents motor #2 from starting before motor #1?

Question 5

Some circuit requirements may demand that the motors turn off in sequence. What does such a circuit require?

Question 6

____________________ forces motors to start or stop in a predetermined order.

Question 7

Figure 12-4

The circuit shown in the accompanying figure permits ____________________ motors to start in sequence.

Question 8

Figure 12-6

In the circuit shown in the figure above, what happens when the STOP button is pressed?

Question 9

How do automatic sequence control circuits which sense motor current work?

Question 10

In a circuit in which three motors turn off in sequence, an overload on any one motor will not have an effect on the other motors.

Question 11

The addition of two ____________________ make it possible to start motors in sequence from #1 to #3 with a time delay between the starting of each motor as well as stopping the motors in sequence from #3 to #1 with a time delay between the stopping of each motor.

Question 12

Normally open auxiliary contacts that control the starting sequence are often called permissive contacts because they permit action to take place.

Question 13

In the circuit shown in the accompanying figure, motor #3 starts five seconds after motor #____________________ starts.

Question 14

Most ladder diagrams show coils connected in parallel.

Question 15

In the circuit shown in the accompanying figure, timer coil TR1 is connected in ____________________ with the 1M starter coil.