LT-4

Question 1

What are the two purposes of any motor starter

Answer 1

1. Safely start and stop motor
2. Provide running (overload) protection to the motor

Question 2

Motor starts can (also) provide

Answer 2

-reveres operation
-reduce voltage starting
-speed control
-sequence control
-remote control operation
-operator safety

Question 3

One of the most common controllers for three-phase motos is the

Answer 3

Across the line magnetic starter

Question 4

Magnetic starters have 2 main parts, what are they?

Answer 4

Contractor and Overload Relay

Question 5

The contractor

Answer 5

Stops and starts the motor

Question 6

The overload relay

Answer 6

Provides running protection for the motor
And
Protects the circuit from overloads

Question 7

What are the two types of contactors

Answer 7

1. Clapper type
2. Vertical lift type

Question 8

Overload relays consist of what two parts

Answer 8

Heater element
And
Normally closed auxiliary contact

Question 9

The CEC requires each like of a three-phase motor to have OLR protection by

Answer 9

Three single-pole OLRs (each with a heat and auxiliary contact)
Or
A single three-pole OLR (with a single auxiliary contact activated by three heaters)

Question 10

Manufactures of motors provide ____ on the inside of the enclosed door

Answer 10

Heater table

Question 11

A tripped OLR is identified by a

Answer 11

-protruding plunger
-a flag
-a coloured disk

Question 12

If a motor starter has tripped because of an overload you must

Answer 12

-determine cause of the overload
-wait for the OLR to cool down
-reset the OLR