T2 Part 8 Motor control

Question 1

Direct on line starting is not recommended for large type squirrel cage induction motors because:

Answer 1

it causes a momentary but severe drop in line voltage

Question 2

A three phase squirrel cage induction motor is said to be ‘single phasing’.
This means that:

Answer 2

one line of a three- phase supply to the motor, has become disconnected inadvertently

Question 3

The stop button in a direct- on- line starter control circuit is wired in:

Answer 3

Series with the start button

Question 4

Which is the most suitable type of conduit to use to connect to an electric motor?

Answer 4

Flexible Conduit

Question 5

In a single-phase capacitor start induction run motor, the start winding is disconnected when the motor is up to speed by using:

Answer 5

A centrifugal switch

Question 6

Does a DOL starter protect a motor against over loading and single phasing?

Answer 6

Yes

Question 7

In motor circuits, fuse or MCBs are used for protection of motor against short circuits and earth faults

Answer 7

Yes

Question 8

Emergency stop button actuators must be mounted on a contrasting
coloured
background.

Answer 8

Yellow

Question 9

An emergency STOP button which when operated, actuator latches in the off position.

Answer 9

Yes