MCQs of Installation and Commissioning of Rotating Electrical Machines (Testing and Commissioning of Electrical Equipments - 2180901)

Testing and Commissioning of Electrical Equipments (2180901) MCQs

MCQs of Installation and Commissioning of Rotating Electrical Machines

Showing 11 to 20 out of 45 Questions

11.

HV test should be conducted if the insulation resistance is ____________ the value defined in IS 4722.

(a)	greater than
(b)	less than
(c)	for any value
(d)	not depend on IR value

12.

The high voltage test of three-phase induction motor shall be applied between the

(a)	windings and the frame
(b)	each phase and the frame
(c)	both windings and the frame & each phase and the frame
(d)	each phase and slip ring

13.

Which of the following is/are not the test condition of the HV test on three-phase induction motor?

(a)	the core & windings not under test are connected to the frame (Earthed)
(b)	only to a new and completed motor with all its parts in place under conditions equivalent to normal working conditions
(c)	only after the IR test get successful
(d)	when machine rotates at no-load

14.

Which of the following is/are the specification of the HV test on three-phase Induction motor?

(a)	test voltage should be of power frequency
(b)	test voltage should be of a sine waveform
(c)	the test voltage shall be commenced at the voltage of not more than one-half of the full test voltage
(d)	All of these

15.

In the HV test of three-phase induction motor, The full test voltage shall then be maintained for ________ .

(a)	1 min
(b)	2 min
(c)	1.5 min
(d)	30 sec

16.

Normally the test voltage applied in HV test of stator winding of three-phase IM is

(a)	1000 V + twice the rated voltage with a minimum of 1 500 V
(b)	1000 V + twice the open circuit standstill voltage as measured between slip rings or secondary terminals
(c)	1000 V + four times the open circuit standstill secondary voltage
(d)	All of these

17.

Normally the test voltage applied in HV test of rotor winding of three-phase IM is

(a)	1000 V + twice the open circuit standstill voltage as measured between slip rings or secondary terminals
(b)	1000 V + twice the rated voltage with a minimum of 1500 V
(c)	1000 V + four times the open circuit standstill secondary voltage
(d)	All of these

18.

The test voltage applied in the HV test of rotor winding of three-phase IM when it is subjected to be reversed or braked by reversing the primary supply while the motor is running is

(a)	1000 V + twice the rated voltage with a minimum of 1500 V
(b)	1000 V + twice the open circuit standstill voltage as measured between slip rings or secondary terminals
(c)	1000 V + four times the open circuit standstill secondary voltage
(d)	All of these

19.

What should be the reason? Motor fails to start

(a)	Supply phases open circuited
(b)	Open circuited starters
(c)	Load torque is much higher than starting torque of the motor
(d)	All of these

20.

What should be the reason? At the start, only thermal overload operates.

(a)	Contactors warned out
(b)	Excessive load torque on starting
(c)	Voltage very low
(d)	All of these

Showing 11 to 20 out of 45 Questions