To connect a welder about 15 feet from breaker box. The welder says
primary amps 40. A wire chart on a website shows #6 as 37.5 amps.
Will #6 be close enough or should I use #4? I know the welder will
not be drawing full amperage most of the time, only on spikes.
Consider what would happen if you put in too small wire. You get to do it
again, and pay more.
Do it once. Do it right.
What if you decide to get a little bit bigger welder? Or if you like
welding, and use it enough to really heat up the wiring?
Copper is expensive now, but nowhere near the cost of doing it twice.
On Sun, 17 Dec 2006 01:17:49 GMT, email@example.com (Doug Miller)
Here's the site: I thought it shoul be higher than that....
It seems to me like the old cable type service entrances for 60A
service were #6-3 plus ground (wrapped around the bundle).
I'm no electrician so I'm not sure what they're giving the specs for but
just think of it this way. According to that table, 14 ga is only rated to
5.87A. We all have a lot of problems if that's the case given the number
of 15A circuits we have in our houses! I'd look for another chart or
better yet, get into an NEC manual. If memory serves, 8 ga THHN/THHW or NM
should work fine for 40A.
Below the table, it does say "The National Electrical Code [NEC] requires
their own cable sizing for premises wiring. Refer to the NEC rules to
determine building wiring, as this page relates to electronic equipment
This is then followed by a sample list of wire guages and supposedly
NEC-permissible ampacities, which I will *not* reproduce here because it's
Sounds about right.
Good luck, and stay safe.
Doug Miller (alphageek at milmac dot com)
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