The best method of carrying out an insulation test on a circuit containing a dimmer switch which cannot be removed is to
A) Turn the switch off
B) Test between live conductors only
C) Carry out the test using a low resistance ohmmeter
D) Test between live conductors joined and earth

Question

Quizplus · Accepted Answer

Testing between live conductors joined and earth will allow for the measurement of the insulation resistance of the circuit while also taking into account the presence of the dimmer switch. This method ensures that the entire circuit is being tested, including any potential leakage paths through the switch. Testing between live conductors only or using a low resistance ohmmeter could result in misleading or inaccurate readings. Turning the switch off is not necessary for this type of test.

The Best Method of Carrying Out an Insulation Test on a Circuit