When measuring the Insulation resistance of a motor winding (winding to earth)

When measuring the Insulation resistance of a motor winding
(winding to earth) using a megger meter, Applied
voltage(1000V) was automatically reduced to 500V. and the
measured insulation resistance values are also very low (in
Kohm range) Can anyone give me a reason???

Question Posted / dum

3 Answers
7495 Views
I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

When measuring the Insulation resistance of a motor winding (winding to earth) using a megger mete..

Answer / sridhar

there are two reasons of getting the value low.
1. due to moisture in the motor
2. winding has become weak

to overcome these problems the methods can be adopted
1. heater or halogen lamp to be provided near to the
winding of the motor to bring the resistance value as per
std.
2. by this above method, the insulation resistance is not
upto the mark, the same winding can be overhauled to
achieve the required insulation resistance value.

Is This Answer Correct ?

3 Yes

0 No

When measuring the Insulation resistance of a motor winding (winding to earth) using a megger mete..

Answer / raghavendran.r

The reason for the fall in supply voltage could be because of the fact Insulation has started conducting heavily as mentioned that insulation resistance is also poor.

Is This Answer Correct ?

1 Yes

0 No

When measuring the Insulation resistance of a motor winding (winding to earth) using a megger mete..

Answer / dum

Thanx Sridhar.. ur answer is clear. But i want to know why the applied voltage is automatically reduced as i have mentioned in my question?? is there any theoretical explanation for that??

Is This Answer Correct ?

0 Yes

0 No

Post New Answer

More Electrical Engineering Interview Questions

BRIEF ME CHECKING PRCEDURE OF BATTERY 12V 26AH

1 Answers DRJ ARDE,

how we can calculate LT side current of transformer

2 Answers L&T,

How do you think they do earthing or grounding in ships and aeroplanes?

9 Answers

what is induction motor

2 Answers

What is a dominant pole?

0 Answers

can we use the 110 v primary Tr 240 v secondary step up Transformer as reverse 240 pri 110 sec

3 Answers Hyundai,

do any one help me to get "C" license,, i have doubts ,,, if mediators ter pls call me,, my no is 8056640042

0 Answers

MY QUATION IS ABT THE MAIN POWER TRANSFORMER IN STEEL PLANT , I WISH TO KNOW THAT WHY TRANSFORMER PROTECTION NOT TRIP AS CABLES ON THE SECONDAY SIDE IS WATER COOLED. TRANFORMER DETAIL NORMAL KVA--150 KVA PRIMARY VOLTAGE --34.5 KV SEC.NO-LOAD VOLTAGE---1.290-908-690V ( WITH PRIMARY DELTA CONNECTED) CONNECTION--D/d (EXTERNAL CLOSED) CONSTANT RATEING FROM--1.290-908V CONSTANT CURRENT FROM--908-690 VECTOR GROUP--D III

1 Answers

1. What is differential relay? How it operates?

3 Answers

can I improve the furnace power factor (10 mva transformer) by adding a capacitor bank before the transformer.Does system power factor vary a lot with the furnace PF?

0 Answers

why all transformer colour is same?

3 Answers OPTCL,

basic princple of induction and synchronous motor

1 Answers

For more Electrical Engineering Interview Questions Click Here