An inspector took the following photograph of a residential home’s circuit breaker panel.
White wires are connected to the neutral bar. Black wires are connected to the circuit breakers in the picture, but there’s one white wire among them. Why would it be wired in such a way (rather than a black and red wires alternating)?
Note: The circuit breaker panel is not labeled.
A pic from Google images of a circuit breaker panel:
Best Answer
The white wire is being used as an ungrounded (hot) conductor, though it has not been properly marked as such. Looks like a fairly large wire, so it's surely feeding a larger 240 volt load. The breaker that it's terminated at, should be a double pole breaker, and is likely rated 50 amperes (check handle label for rating).
The load being supplied by this circuit will require 240 volts only, so a grounded (neutral) conductor will not be required. Because of this, the circuit will be wired with a two conductor (plus ground) cable. Two conductor cables are manufactured with a black, white, and bare (or green) conductor inside. When using this type of cable for 240 volt circuits, the white wire can be used as a hot conductor. According to National Electrical Code, the white wire should be marked to indicate this repurposing.