I’ve been working on a bathroom remodel and came across some creative wiring. Actually it’s not too creative. For a five wire installtion to an exhaust fan, the previous owner/electrician/handyman ran a pair of 12-2s and a single 12ga wire along side, i.e., not a 12-2 and a 12-3. Should I replace one of the 12-2s and the single 12 with a 12-3 or is it ok to leave it as it is?
Thanks!
Replies
Replace it.
With one exception it is not legal to run an separate wire that is outside a cable.
That one exception is to add a ground to existing non-grounded receptacles.
You can get 4 conductor cable (plus ground) which I am guessing would work here (fan, light, heat and neutral). But you won't find it in the hardware or big box stores.
You can buy 250' coils of 12-2-2. It's got the standard black, red, white, and bare copper ground, but this cable has an added striped conductor for these three-tool fixtures.
If you use the cable as three hots and one neutral, make sure you are only feeding it with one hot line from the panel. There is a possibility of overloading the neutral with anything more than a 12-2 feed to that switch.
Enjoy your project!
-Rob
Either get some 12-2-2 wg or run wire in conduit (which would probably necessitate changing out the boxes to steel to use flex, or PVC designed for ENT [smurf tube]).
The Code says that all the current-carrying conductors in a circuit have to be in the same conduit or cable (the exception being when very large conductors are run in paralell in two or more conduits).
If neither of these is an option, at least keep the two cables very close together and run the heater power and the neutral in the same cable. The issue is the possibility of the conductor heating up because the EMFs of the supply and the return wires are not cancelling (because they're not close to one another). Heat the conductor up sufficiently, the insulation fails, and you get a short.
Cliff
Bill, Robo, and CAP,
Thanks for your help. I took your advice and rewired the fan the right way. Good thing, turns out that the previous "installer" didn't bother to use a cable hold down/insulator where the wires enter the fan box. Nice sharp metal edge coupled with the fan's vibration did a nice job of cutting through the insulation. Just a short waiting to happen!
Thanks again,
Dave
Re: " Nice sharp metal edge coupled with the fan's vibration did a nice job of cutting through the insulation. Just a short waiting to happen!"
In electrical work details and attention to them matter.