Adding a 220v outlet for a welder.

[jshultz78]

I asked this on another site but got NO help, except for "pay someone to do it"

Right now, there's a 220v 10ga line with a 60a breaker run into the shop for some old printing presses, but they have the old style plug, I bought one of those 50a wall mount outlet boxes that has the socket for a welder. The existing plug is inside the shop, and I want to put the new one in the garage, which is directly on the opposite side of the wall of the existing plug. Maybe 8" through the wall. The presses are never used so the only thing that will be on the circuit will be the welder.

My question is, can I just pigtail off the existing outlet with about a foot of 10 or 12 ga wire, run it through the wall and into the new outlet? I've done it before with 110v adding an extra light to a switch, Is the 220v wiring basically the same as 110, but just with more volts?

Or would the easiest way be make a super short extension cord that has the old style male plug that will plug into the existing socket? or would that hurt the voltage going to the welder, going through that many plugs?

Also, I checked it with my DMM and it reads about 248-249v, even the plugs in the house read 124-125v. Is that acceptable or too high of a voltage?

 

[BMB]

I'm not an electrician and haven't stayed at a Holiday Inn, so I would get more than my opinion.

If the outlet you want to pig tail off is no longer in use why don't you remove the receptacle and then tie off of the existing wiring to your new receptacle?
The old one will basically become a junction box, just replace the missing receptacle with a blank cover.

And yes the wiring is similar to 120v you are just dealing with two legs of 120v instead of one (for single phase).

Does your new receptacle for the welder have 3 or 4 slots?

 

[jshultz78]

Two slots and the "u" ground. Looks like a bigger 110v plug

 

[joe_padavano]

10 ga wire is far too small for even 50A. Depending on the wire type and length of the run, you might squeak by with 8 ga for 50A, but I always use 6 ga to be safe. A 60A breaker definitely should have 6 ga wire. Verify what wire size is really connected to that breaker.

 

[wyliesdiesels]

If this outlet will be used STRICTLY for a welder then the wire can be undersized but the outlet should be so marked and only the welder can be plugged into this outlet. If other machines will be plugged into the outlet, then the 50a breaker should be changed to the correct size breaker for the type of 10ga wire(NM/Romex, THHN, etc.).

If the existing outlet wont be used why not just remove it and splice new wire onto the existing wire and connect to your new outlet.

 

[jshultz78]

The 10 ga coming from the breaker is going to be the welder only. What I did was just remove the old plug, and pull the wire through the wall and hook up the new plug, Its been years since the presses have been used, and I doubt if they ever will again.

 

[jshultz78]

The hobart site says for the 210mvp that it requires 6625w, so convert that to amps, it's roughly 27amps. If that's anywhere near correct. lol

 

[wyliesdiesels]

Whats the duty cucle of the welder? Duty cycle is important when sizing branch circuits for welders.

And in regards to your question about permissable voltage levels that i missed in your first post, yes those readings are fine. Most utilities policy is +/- 5% of nominal 120v/240v.