I bought a used Miller Syncrowave 351 Welder for my garage. I contacted Miller Electrics online
Tech service. They sent me this. The electrical service guide for a
Syncrowave 351 shows that at
50/60HZ single phase, input voltage at 230 without power factor
Correction you
Will need a 125 amp time delay or a 125 amp normal operating breaker.
Minimum input conductor size in AWG is number 4.
Maximum input conductor length in feet (117)

So my question is- Is the proper way to do
This to- Put receptacle in garage-run #2 copper (or #4) cable back to a 125 amp breaker in my panel box? Anyone ever do something like this? I know you will probably say to upgrade my panel from 200 amp. I do know some one that has same machine hooked to a 100 amp breaker-he said he has never had a problem. Thanks, Matt

I see it requires a 175 amp CB for the unit without power factor
correction as shown on page 16 of the manual: http://www.millerwelds.com/om/o354g_mil.pdf

In any case, your friend probably does not do large, thick, or heavy welding, so the draw is not at what the maximum draw can be for this machine.

This will probably be the same situation for you, just as long as you understand that what ever line you do install will limit your welding capabilities.

Units such as this are usually connected directly, see page 21 of the manual. High amp outlets are available, pin and sleeve type, and are very expensive, in the range of $300-350 each.

If you only have a 100 amp service, then hopefully you do not do heavy welding, as you will be limited by that size main breaker.