where do these wires go?

December 26, 2009 7:03 AM

I'm wiring NM-3 cable into a fuse box. Where do the wires go?

I'm putting an NM-3 cable into a fuse box. There are four wires: bare, white, black, and red. I know the bare is ground, the white is neutral, and assume both the black and red are live. I know where the ground, and neutral go. The black is attached to a fuse, is the red just attached to another fuse? Note: this isn't a 240v circuit.

posted by crazylegs to Technology (5 answers total)

NM-3 can be used to carry the current for two 120v circuits.

What is on the other end of your wire?

If you need the black and the red to be live, just wire them each to their own fuse/breaker.

If you don't need both, you can just disregard the red wire (cut it/cap it off)
posted by davey_darling at 7:23 AM on December 26, 2009

That depends what the other end is hooked to! Your question is unanswerable as-is.
posted by fritley at 8:05 AM on December 26, 2009

Whether you want 240V at the other end or a split dual 120V at the other end the red wire needs to go to another fuse, and this is a very important part, attached to the opposite leg of your incoming power. If it doesn't in the first case you'll get nothing (IE: your device won't work) and in the second case you'll get a dangerous condition where the neutral line can be loaded with twice the current it is rated for causing your house to burn down.

Unlike breaker panels fuse panels do not have a standard way of locating fuses on power legs. However if you have a double pull fuse block in your panel those two fuses will be located on separate legs.

If you don't need the second circuit/240v then the red wire should be taped back on itself and then taped up. Ideally it should be left the same length as the black wire and not cut short. The same should be done on the other end.
posted by Mitheral at 8:43 AM on December 26, 2009

Note: at the risk of being slightly less than helpful, this question falls into the category of "if you have to ask, you probably shouldn't be doing it." Please be careful.
posted by davejay at 8:46 AM on December 26, 2009 [3 favorites]

Yeah, need to echo davejay: if you're asking AskMe for advice on how to wire the breaker box in the your house, you need to stop and call an electrician. Too much current, too much fire risk. Safely wiring your house involves both following the relevant code and knowing a bunch of tricks of the trade, which you're only going to learn from either being or following a real-life electrician.
posted by range at 10:38 AM on December 26, 2009