The white wire goes to an external capacitor that has a red wire going into the motor. The other two wires (black & green) go directly into the motor. Which wires are positive & negative?
VALARIE
Comments
This, I’m afraid, is going to be a non-answer for you. But fan motors are typically AC driven, not DC, so polarity is not the issue. The presence of a capacitor further supports this (or the DC voltage would simply be blocked).
If you’re in the U.S., green is earth ground, white is neutral, and black is hot, for 110v systems. Neutral is usually tied to ground to clamp it to 0v.
However, when you get into single phase 220v, there is no real standard. Often the white lead goes to one side of 220v, black to the other side, with NO lead going to neutral, and green going to ground. Some systems, though, use a 4-wire connection for single-phase 220v, where red goes to one side of the 220v, black to the other side, white to neutral, and green to ground. The purpose of the 4-wire connection is to tie neutral to ground to clamp it at 0v.
If you’re in Europe, it’s a different story. So you can see that you should at least talk to a local electrician before you run the risk of frying something, or yourself.