DIYbanter - View Single Post - Rewiring a Vent/Heat/Light unit in bathroom

Nate Nagel

wrote:
On Apr 22, 5:32 pm, "RBM" wrote:

This electrician would run a 12/4 Romex, and if the unit had four functions,
light-heat-fan- night light, I would run 1/2 inch greenfield with a ground,
neutral, and four hots

Sorry for the ignorance... here are some questions:
1) "1/2 inch greenfield" is a type of conduit?

yes. think BX without the wires in it. You pull individual conductors
of THHN through it.

2) This unit does have four functions, for the "ground and neutral",

No it doesn't, he's talking about how many hots you need. you have
three functions, plus you need a neutral and ground.

would you use a 12/2 and clip the other wire? Would this also mean
the 12/4 would have its ground clipped?

No. read my earlier post - you need to get rid of all that's existing
and pull new cable. I guess RBM has actually seen 12/4, I haven't but I
haven't looked nor had a need for it. The whole point is, you need your
currents to sum to zero within every single cable assembly, and that's
not currently happening with what you have. The reason for this is to
minimize inductive heating of the wires.

Like I said before, if you have one of the functions where you can
isolate the neutral you can pull one 12/2 and one 12/3 and make it work.
If you can't, you need to either pull a 12/4 if such is available or
else go with greenfield, EMT or something like that - which will likely
involve painting and patching at some point.

good luck

nate

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