How do you measure electrical insulation resistance value?

By Megger testing (meggering) of the motor any one can measure the IR of the motor. MEGGER is a device used to measure IR. Analog Megger device may generate 500 volts..it gives coil to coil or coil to body IR value...it should not be less than 2 Mega ohm, generally it should be or kept more than 5 mega ohm...thanks

...DEEPAK RAJPUT