My home has a relatively typical (in America) 100 amp 240v feed accomplished via three conductors - two 120v "hot" wires and one neutral. This gives me my 240v circuits (the two hots) and my 120v circuits (one of the hots plus the neutral).
Recently my neighbor severed two of those feeder wires while digging a trench. The two severed wires were one of the two hots and the neutral. Therefore, my home was only receiving one 120v hot wire and nothing else.
Doing an inventory of my home, I discovered the following:
- None of the dedicated 240v appliances worked at all (oven, HVAC, table saw, etc)
- Some of the standard 120v outlets and lights worked perfectly (and verified as stable with a multimeter)
- Some of the standard outlets and lights fluctuated with voltages ranging from 0v to 60v (rising and falling; not static).
My questions are:
How did those 120v outlets work at all, much less perfectly, when there was no neutral? How was there any circuit with only one hot and no "return path"?
Why did some of the 120v circuits exhibit a varying voltage between 0v and 60v? What could cause that?