Motor Control

Question 1

The question mark sensor

Answer 1

Bourdon tube sensor

Question 2

Types of pressure switches

Answer 2

Bourdon tube
Bellows
Diaphragm

Question 3

Pressure switch with springs in it

Answer 3

Bellows

Question 4

Pressure switches commonly used for

Answer 4

Safety devices to protect system from high or low pressures

Question 5

What is the differential of a pressure switch.

Answer 5

The difference between the cut in and cut out pressure of the switch.

Question 6

What is the range of a pressure switch

Answer 6

The overall pressure over which a switch can operate

Question 7

Float switches are also called

Answer 7

Liquid level switches.

Question 8

Temperature switch (thermostat) are used for

Answer 8

Automatic control in heating and cooling systems.

Question 9

How are most temp switches constructed?

Answer 9

Bimetallic strips.

Question 10

What are mechanical limit switches used for.

Answer 10

Prevent over travel and used in reversing motor applications.

Question 11

Maintained contact limit switch

Answer 11

Have contacts that remain in position even though the force is removed.

Question 12

Timed contacts limit switch

Answer 12

Have a delay between the time the operating mechanism is moved and the time the contacts operate.

Question 13

Photoelectric switch.

Answer 13

Prox sensors that contain a beam transmitter and a receiver. (Garage door)

Question 14

What makes up a control relay?

Answer 14

Electromagnetic coil

One or more sets of contacts.

Question 15

Why to use control relays

Answer 15

Used as aux contacts to switch low-level currents.

Question 16

Contacts rating

Answer 16

10 amps
As high as 600v
Inrush or make rating
Normal or continuous rating
Opening or break contact rating

Question 17

On delay relay

Answer 17

Time delay occurs after the relay is energized.

Question 18

Off delay relay

Answer 18

Time delay occurs when relay is de energized.

Question 19

Different types of timers

Answer 19

Dashpot
Pneumatic
Motor driven
Electric

Question 20

Electric timers use what in the base.

Answer 20

Alignment key

Question 21

Why would you use control relays with motor starters?

Answer 21

Add more aux contacts

Question 22

Rating of 10 amps on a relay is

Answer 22

Continuous current

Question 23

What is a latching relay

Answer 23

A relay that is electronically activated and mechanically held.

Question 24

Oil filled pot and piston associated with.

Answer 24

Dashpot timer

Question 25

The movement of air using bellows or diaphragm assembly is associated with

Answer 25

Pneumatic timer

Question 26

What type of timer best used for switching a motor on and off at 1 hour intervals

Answer 26

Motor driven timer

Question 27

What fundamental principal do electric timers use?

Answer 27

R-C time constant

Question 28

Which time delays have instantaneous contacts?

Answer 28

Either type can have timed or instantaneous.

Question 29

What is plugging

Answer 29

Quickly stopping a motor

Question 30

How do you plug a motor.

Answer 30

Try and reverse the motor and then stop before it can turn in the opp direction.

Question 31

Another name for plugging switch

Answer 31

Zero speed switch

Question 32

What is the purpose of the lockout relay in a plugging switch

Answer 32

“Safety latch” holds the contacts open until motor control circuit has been energized.

Question 33

What is anti-plugging.

Answer 33

Using a zero speed switch on reversing motor drive so the motor can’t be reversed until it’s stopped.

Question 34

An industrial temperature switch that utilizes a fluid filled temperature sensor is called a…

Answer 34

Remote bulb switch