Electrical motor

The end cover which is connected to the fan side is namely as a

• non-drive end cover.

• drive end cover.

• end drive cover.

• end non-drive.

The motor frame is made of .......

 

• cast steel or cast brass.

• cast steel or cast copper.

• cast steel, or cast aluminium.

• cast copper or cast aluminum .

The following motor enclosure are not suitable to be used in oil and gas plants except.....

• totally enclose fan cooled.

• drip proof.

• flameproof

• pipe ventilated.

How many slip rings would you expect to find on the shaft of a squirrel cage motor?

 

• Four.

• Three.

• Two.

• None.

The three phase squirrel cage induction motor cannot be started when

• the capacitor is malfunction.

• a starting winding is broken or open winding.

• two of the supply voltage is out.

• a DC supply is malfunction.

The speed of rotating magnetic field for a three phase squirrel cage induction motor depends on...

• supply frequency and rotor speed

• supply frequency and number of stator poles.

• number of stator poles and motor type.

• rotor speed and slip speed.

The different between the rotor speed and the synchronous speed is called

• gain.

• torque.

• locked current.

• slip.

When one of the line fuses is blown the running three phase motor is said to be in

• two phasing condition.

• single phasing condition.

• stalled condition.

• maximum torque condition.

The following connection are not true about a Delta connection except

• connection is R1Y2, Y1R2 and B1B2.

• connection is R2Y2, Y2B2 and R2B2.

• connection is R1Y1, Y1B1 and R1B1.

• connection is R1B2, Y1R2 and B1Y2.

The following isolation of supply procedure are true for motor overhauling except...

• prepare and apply a permit to work (PTW).

• isolate the circuit breaker or isolator.

• rack in the circuit breaker or MCC.

• lock the breaker enclosure and put a warning tag.