The electrical officer is about to check the insulation resistance. When advice should you give to him as to what temperature and or when he should check the motor insulation?

Correct Answer: Option B — Testing should be done at or near the motor temperature as the insulation becomes leaky at high temperatures. .

Insulation resistance testing must be performed at or near operating temperatures because heat increases the mobility of charge carriers within the dielectric material. Testing at operating temperature provides a more accurate assessment of the insulation's integrity under actual service conditions, as insulation is most prone to failure when hot.