On 06/06/07 08:05 am Doug Miller wrote:

Our house has 3-conductor wiring for the range and dryer. Would it be OK
according to the NEC to run an additional (green) conductor alongside
the existing wiring and replace the receptacles by 4-pin ones? If so,
what gauge? Or would the existing wiring have to be replaced?

Yes it would be OK,

No, it's not. All conductors for a circuit are required to be in the same
raceway or cable. [2005 NEC, Article 300.5(I)]


Except for a few feet of EMT where the wiring for the dryer outlet come
down the wall* (and I could easily get a new ground wire in at the top
end to connect to a 4-pin outlet), there are no raceways: the existing
wiring comes out of the panel (which is surface mounted, so I could
easily run the ground wires out through the same knockout/clamp) and is
stapled to the underside of the joists.

*And it's just occurred to me that running Romex in conduit probably
wasn't kosher either. I wasn't the one who did it.


but it's not necessary.

That's true. Code permits connecting new appliances to *existing* 3-wire
circuits, but prohibits installing *new* 3-wire circuits for this purpose.

If it were me, though, and it wasn't too much effort or expense, I'd pull new
4-wire cable.


That's what I'm trying to decide. Each run is approx. 15ft. What gauge
should be used? -- either for a separate ground wire or for whole new
wiring runs.

Perce