[TheForge] Capacity of Electrical wire

[John Husvar]

On 5/20/06 9:56 AM, "Jerry Smith" <jerry_smith at anvilsandinkstudios.com>
wrote:

> I am putting in new service and need to run the lights
> as well as a milling machine, along with a powerful
> TIG welder. What wire do I need to run from the meter
> to my breaker box? This is a 125 foot run.
> 

How much amperage is required? What rating is the main breaker at your shop
panel? Is it overhead or buried wiring from the meter to the shop?

For a 100 Amp service at a 125 foot I'd run AWG 1 or even 1/0 if underground
direct burial. #2 ACSR if overhead then 2-2-3 SE from the ACSR down to the
panel. I'd also check with your local Building Dept. to see if there are any
locality specific codes.

You might have to carry a ground through to the shop from the meter or a
breaker in the house panel as the National Electrical Code, IIRC, would
consider the shop panel to be a sub-panel of the house panel. If the shop
has its own service drop, that doesn't enter in.

How are the chances you'll be using enough machinery at once to approach the
main breaker limit? IIRC, you once mentioned you might end up employing a
few people. More people, more likelihood of more than one machine running at
once.

Used to was farmers ran multiple drops to panels from one meter on a pole
someplace, sometimes even without any disconnect at the meter. I don't think
that's acceptable any more.

John, trying to remember a long way back when NEC compliance record made the
difference between having an easy time with inspectors or a hard time if a
corner had to be cut, but could be cut safely.