minimal insulation resistance

[LordError]

what is the minimal insulation resistance should a motor run? is there any formula for this one? depending on the voltage source i think? let say for 480V motor what would be the minimal insulation resistance it should run safely?

thanks.. n cheersss!!!



marcus

 

[Oznog]

Insulation is not rated for "resistance" except in some exotic applications and laboratory procedures.
Insulation is rated for breakdown voltage. Obviously an insulation over 480V is required for a 480V line. With higher temp operations (as you would see in a motor), or high frequency, or otherwise tough environment, you will need to get a significantly higher voltage rating.

 

[Phasor]

With a 1000V Insulation Resistance Tester (IRT/Megger) an acceptable reading is above 1 megohm. However in practice, it is normally much higher than that - IMHO if you have 1 megohm insulation resistance, there is a pending problem.

 

[LordError]

thanks

thank you phasor for your words. it seemed i have a problem with my 250KW sea water pump motor. it has a 1 MOHM insulation. what i did is put lamps around the motor to heat it up, maybe mists causes the downfall of the reading as the motor stands for a while due to delayed PMS activities.

anyway thanks for the info. keep it


cheeersss to you !!!!!!



marcus

 

[LordError]

oznog thanks for ur comment also, a big appreciation to u also.


cheeersss!!!


marcus