In article . com, "Clint" wrote:

No way to know that, without knowing the requirements of your
compressor and
welder. How many amps do they require? And at what voltage? (120 or
240)

First...thanks for the quick responses. Second, my plans are to make
the garage into a place where I can work on my Jeep and change the oil
in the car and truck...nothing too extensive. My hopes were to install
a 100 amp sub panel in the garage, and have the capacity to do pretty
much what I please out there. A 240 welder in the future is not out of
the question, so I would definately like to take that into account now.

A 100A subpanel ought to take care of pretty much anything you might want to
put there -- welder, compressor, table saw...

For a 100A 240V feeder, you need three 4ga copper wires (type THHN or equiv)
for the two hots and the neutral, and one 8ga copper wire, bare, for the
equipment ground. And that's going to mean a pretty substantial conduit.

Any compressor would be to run air tools...not a paint booth ar
anything like that. The existing conduit looks to be 3/4" or so, and
there is already 240 out there to a fuse box.

Well, that's going to be a problem. Code limits you to two 4ga conductors in a
3/4" conduit, and, quite frankly, it would be a hell of a challenge to pull
even that through a 3/4" conduit of any significant length.

The Code limits you to 6ga copper, maximum, in a 3/4" conduit, for three
current-carrying conductors, which in turn limits you to 60 amps, tops. As a
practical matter, though, it's going to be pretty tough to pull three of
anything, plus a ground, any bigger than 8ga, and even that won't be real
easy.

Your best bet looks like installing a larger conduit. Looks like you'd be
Code-compliant with a 1" PVC conduit, but I'd sure recommend something a lot
larger than that -- 1.5" or bigger -- to make the wires easier to pull.



--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.