Re: Cable current capability

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jeremy Scott by way of Terry Fritz <teslalist-at-qwest-dot-net>" <supertux1-at-yahoo-dot-com>

Hi,

I asked about this a few weeks ago, and I had never
done any 240V wiring. I bought and read a lot of NEC
Code books about doit-yourself wiring and this is
the result:

What you'll want to do is install a circuit and
outlet that can power a conventional appliance oven.
At least, that's what you'll tell the sales people
at your local hardware store or the electrician if
you hire one :)

The plugs and sockets are 'NEMA-50' and have three
flat prongs and one u shaped prong (ground). Most
NEMA-50 outlets/plugs come with another prong
that is L shaped. It's when you want to use a
NEMA-50 outlet for NEMA-30 purposes (30A) which is
okay. (but not vice versa) So when you open up
your plug kit, throw away the L shaped prong.

You'll want to use the 6/4 wire because that is the
easiest to cut/pull/connect. 6/4 wire can safely
handle 50A at 240VAC but no more, 4/4 can handle
higher current but it's such a pain to run. Don't
run the 6/4 cable more than 100 feet, or else the
resistance of the wire will cause voltage drop
and that means heating of the wire which is bad.

If you install the circuit in your garage or
outside, you'll probably need a GFCI 50 Amp
dual 240V breaker or else you'll probably
nullify your home owner's insurance policy.
Infact, if you do it any other way than
I specified, you will probably be in
violation of some code, and you probably
won't be covered if your house burns down.

The easiest way to find 50A GFCI breakers is
is to look for an outdoor hottub wiring kit
and pull the breaker out of that. Better yet,
use the whole thing as a load subpanel next
to your main panel. Depending on the current
capacity of your house's main box and local
codes, you may be REQUIRED to use a load
subpanel for additional 50A circuits.

50A at 240VAC will give you 50A * 240VAC = 12,000W
which is enough to run a 10KVA pole pig. The
10KVA pig will happily try to pull the entire
power grid to your house, so you must use a current
limiter. I recommend the Lincoln AC225 adjustable
welder from Home Depot.

It sells four about $250-$300

Be Safe!





--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "Richard W. by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <potluck-at-xmission-dot-com>
 >
 > Hi all,
 >
 > I have two AC cables. One is 50 feet of 6/4 the
 > other is 20 feet 4/4. I'd
 > like to use the longer one, 50ft. 6/4, to power a
 > 10Kva pig, 240vac. Is
 > that cable heavy enough considering it's length?
 > I've never done house
 > wiring of any kind and this hobby really challenges
 > the limit of my
 > knowledge of 240vac supply handling. There's an
 > empty slot in the breaker
 > box where I can install an extra 50 amp tandem
 > breaker so getting the
 > 240vac in the first place shouldn't be a problem as
 > far as I can see.
 >
 > Thanks!
 >
 > Rick W.
 >
 >


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