Deck 16: Limit Switches

Question 1

Generally, limit switches are used as ____________________ devices that control the coil of relays and motor starters in control circuits.

Answer 1

pilot

Question 2

Figure 16-11

In the accompanying figure, what happens when the DOWN button is pressed?

Answer 2

When the DOWN push button is pressed, control relay CR energizes. The normally closed CR contacts connected in series with M contactor opens to interlock the circuit, and the normally open CR contact connected in series with the solenoid coil closes.

Question 3

Limit switches contain only a single set of contacts.

Answer 3

False

Question 4

The ____________________ switches are approximately one-half to one-quarter the size of the basic switch.

Question 5

In the accompanying figure, if the UP push button is pressed, what will happen?

Question 6

A subminiature microswitch employs a similar spring contact arrangement as the basic micro switch.

Question 7

In the accompanying figure, a platform is used to raise material from the bottom floor to an upper floor. A(n) ____________________ is used to raise the platform.

Question 8

When a bumper arm is impacted, it will not cause the contacts to change position.

Question 9

Figure 16-04

In the accompanying figure, what does the wedge drawn under the switch symbol represent?

Question 10

Limit switches are momentary contact (spring returned), but not maintained contacts.

Question 11

Figure 16-10

In the accompanying figure, when the platform is to travel from the upper floor to the lower floor, a(n) ____________________ opens and permits oil to return to a holding tank.

Question 12

What is the function of limit switches?

Question 13

Figure 16-01

In the accompanying figure, the ____________________ detects position of boxes on a conveyer line.

Question 14

The basic micro switch can be obtained with a variety of different activating arms.

Question 15

Name two characteristics of a micro limit switch.