The well pump in my brother's house is wired strangely to me.
A single 12/2 BX enters the disconnect box, white on one fuse and black on the other, and out 2 wires to the pressure switch and out 2 wires to the pump controller.
The voltage across the white/black BX in the disconnect box is 240V.
No 3rd wire going to the pump?
What gives?
Best Answer
It's a perfectly normal 240V circuit. There's no need for the neutral, since nothing in the circuit requires 120V.
It must have been installed before safety grounds became mandatory; in a modern installation, you'd also have a green wire connecting the cases of all the elements (disconnect, pressure switch, pump) together, tied back to the ground at the main panel. If all of the wiring is in metallic conduit, the conduit may be meeting that requirement. Personally, I tend not to trust the electrical continuity of conduit.