Ahren C asked:


What I mean is, how can I determine whether two or more circuits are using the same neutral wire to carry current back to the box. To the best of my understanding, this should not be done with more than two circuits–and in that case, they need to be using opposite-phase hots. I have good reason to believe that at least three of the four circuits in my apartment are wired this way, and I would like to determine whether the fourth is also using the same neutral wire.

Claudette