As an electrical engineer we all know about IR test or insulation resistance test, what is it and why we need to test.
You are either marking a good equipment as bad or marking a bad equipment as good -Wrong decision of IR test requirement for an equipment.
Calculate minimum insulation resistance test result requirement for an equipment:
The required formula is –
R=1+V, Here R=resistance in mega ohm(MΩ) , V= equipment rated voltage in KV.
So if we like to check a machine rated voltage is 11 KV, the minimum tolerated insulation resistance will be R=1+11=12MΩ, and for a motor with 220 voltage rating the IR value will be R=1+.220=1.2MΩ.
This data I have got from the official manual of Fluke.