Howdy,
(NOT an electrical expert. If you kill yourself or your family because
you thought I knew what I was talking about, that's your problem.)
On Thu, 24 Mar 2005, Scott Hall wrote:
> and something to discuss: this is a 300 amp input machine. clearly I
> won't
300A input? Really? I wouldn't have thought you could get a 300A input
welder into the back of a pickup... :-) Does it have a plug on it? If
so, post a picture somewhere! :-)
Like others, I suspect you're talking about the output, not the input.
There should be input power requirements somewhere. The manufacturer is
certainly the place to ask questions about what happens if you run the
welder on less power than its rated for... I suspect it won't matter at
all. Miller & Lincoln both have good websites, you can probably download
the manual. It'll have a section on how to install.
That said, if you're in the 50A or less input power requirements, I'm a
big fan of using electric range receptacles... These are typically rated
at 50A (or maybe 55A?) and are readily available. Then you either install
new plugs on your various 220VAC stuff or make some adapters. Be sure to
use cable rated to handle the current (6 guage, off the top of my head,
but be sure and check it. It'll likely also depend on the length of the
run).
As to running a line from the breaker box... First, be aware that the main
power feeds into the box are live whether the main breaker is on or off
(which is obvious when you think about it, but not as obvious if you
don't). I.e. there is enough power in there to kill you, no matter what
position the main breaker switch is in. Some houses (mine is one) have an
outside electrical disconnect switch, and a more remote main box. With
those, you can shutoff the box entirely. Be careful with all this, and
before you grab or work around anything metal, check for power with a
multi-meter. Making a mistake with 220 can kill you. Making a mistake
with 110 probably won't, but it'll still hurt a lot. :-)
Now, if you want to run a 220 50A line from your box to the garage...
First, get a 220V 50A breaker for your box. There are different styles,
depending on which box you have, and you have to have room in the box for
a double-sized (twice as tall as a 110) breaker (if you don't have room,
chances are that you can get some double 110 breakers to free up a couple
slots). Get enough cable to go from the box to your outlet. Make sure
the cable is rated for the amperage and distance you're running... I
_believe_ 6 guage will work, but check it. I can't remember what its
called (6/2?), but you want two insulated wires and one ground. Check all
this against codes or a real reference.
You also need either an outlet box (get the deepest one you can find) and
an outlet (make sure its rated for your breaker's amperage) or a surface
mount outlet. Install the box, run the wire (this is harder than regular
12/2 or 14/2, since its thicker. Surface mounting may be easier, but I
don't know much about it code wise... You may be required to use conduit
or something), connect the outlet (swear here at how unflexible the heavy
guage wire is) w/ the two insulated wires going to the two angled plugs
and the ground going to the straight lone plug. Staple the wire so that
it can't flop around or whatever.
At the box, SHUT OFF THE MAINS (and remember that bit about the incoming
power lines still being live!), then remove a knockout (little metal disc
that you can pry out of the box), install your wire clamp/protector dealy
in the resultant hole (my brain is refusing to remember the proper names
for things... These come in different diameters, make sure you get one
that matches the size of the knockout). Feed your new wire into the box
(the incoming power is still live!) and install your new breaker (many
just push/snap/clip on, but I've not seen every box out there I'm sure).
Strip the outer sheath on the wire from somewhere up near where it comes
into the box, then bend the individual wires to where they need to go.
The ground wire will go to the ground bus, and the two insulated wires
will go to the two terminals on your new breaker. Cut those to length,
strip as necessary, and connect everything up. Take a deep breath, turn
the mains back on, then turn on your new breaker.
If there's fire, you did it wrong. :-)
Mark
(NOT an electrical expert. If you kill yourself or your family because
you thought I knew what I was talking about, that's your problem.)
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