B A Lyn Fatt wrote:
- snip -
> There is no neutral wire, so it looks like the
> conduit is being used as the ground (or is that
> neutral?)
Brian,
When you are dealing with 220 only service, you have two "hot" legs
(each with a 110 volt potential to the neutral and 220 to each other).
You can get away using the conduit for the ground in a 220 only circuit
as it normally carries no load unless there is a short to it (it helps
to protect you from shock).
If you were to use one of the legs separately for 110, you actually
would be loading the conduit with the same current as the leg--the
conduit is not designed to carry current, so you should run a 14# (15
amp capacity) or 12# (20 amp capacity) common back to some copper
service.
> box is the clothes dryer. Close by, there is a 110V
> box, with three outlets, built into the wall. One
> of the outlets is a higher amperage 110v AC for the
> washing machine.
This sounds like the place to start. You should be able to get by with
a short piece of 14#-2 with ground as long as you don't have to surface
mount it. If you need surface mounting use conduit with TH or just use
armored (BX). It costs a good deal more, but if you have a relatively
short run that will be exposed, it is a real labor saver. TH is cheap,
but you need three of each and you also have all of the conduit
fittings, cutting, snaking, etc. For a short run, probably not worth
the extra time.
> I figure the *easiest* way is to run a hot wire from
> one side of the 220AC box, (which is a suface mount
> box, not built into the wall) up to the new outlet
> by the door opener, but what about the neutral?
>
> Do I just use the conduit for this?
This would be a safety hazard again as you are actually loading the
conduit with current during normal operations.
> What about a 30 amp cct breaker or GFI in case I
> decide to use the overheard outlet for something
> else?
You should have a breaker already "upstream." There will be no
advantage of adding one here. If you also are switching that receptacle
for the light, you'll need a separate leg for the unswitched
receptacle. If you choose to go this way, you probably are further
ahead to run conduit and use four TH's:
black - hot switched
black - hot unswitched
white - "common"
green - ground (unless you are using metal conduit)
This would allow you to switch the light and have uninterrupted 110 for
the motor and other applications. If you want GFI, it is a lot cheaper
($8) just to use a GFI receptacle in the first outlet--wired
appropriately, everything "downstream" from it will be GFI, too.
You might want to look over the wiring faq posted and/or buy a short
paperback like "Wiring Simplified" by Richter and Schwan ($5.50)--you'll
be glad you did and you might save yourself some problems (shorts,
shocks or worse). That concrete floor in the garage provides a pretty
good ground (through your body) if you don't do things correctly.
The old bromide is if you screw up plumbing, you might get a wet floor.
If you screw up wiring, you might burn down the house.
good luck,
doug
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