Megger 3 phase motor with thermistor

[adsmith]

Hi guys

Do you carry out an insulation resistance test on a 3 phase motor with thermistor protection as you would without thermistor protection or does extra caution or process need carrying out differently?
First time coming across one

Thanks

 

[westward10]

Testing the motor should not affect the thermister protection. Can you see the thermister connections in the terminal box.

 

[James]

agree with @westward10 ,
if the thermistor terminals are separate to the windings ( I expect they are) then it is also worth testing resistance between thermistor and each winding (should be open circuit, any connection between thermistor and winding is normally a sign of a melted motor.

 

[snowhead]

Everything wot they said ^^^^^^^^^^^^.
The thermistor is usually in the control circuit.