120v and 240v same work box

[snakevargas]

Is there anything un-code-worthy about putting two different branch circuits and recepticals, a 120v-20a and a 240v-20a in the same work box? I'd wire them individually with 12-2 to the panel.

These would be for running my 120V welder and my 240V plasma cutter respectively.

Common-sense wise, they look a little similar, so that could get confusing. Practial-wise, is it going to be difficult to find an outlet cover that had a duplex receptical (for the 120V) on one half and a single receptical (for the 240V) on the other half?

I have to install old-work boxes either way, it's just a toss-up on whether I want two old-work boxes or one double-old-work box.

 

[BraveSirRobbin]

That could get messy if you try to plug in both your welder and a 120 volt appliance in at the same time wouldn't it (as far as the plug's physical sizes)?

 

[sda]

OK to have 120 and 240 circuits in the same box.
Ties the grounds together.
On the 240 circuit, remark the white as black.
 
Does the welder manual have any wiring requirements?
I know you said a 20A circuit, but if the manual says to use a 15A circuit that's what you should do.
Its OK to run 12/2 or even larger for future use, but still use a 15A breaker.
 
If the welder has a standard 5-15p plug, then you can use a standard duplex receptacle.
Use a commercial grade one because you'll be running a lot of amps through it.
Its not code to have a 20A circuit feeding a single 5-15r receptacle.
 
If the welder has a 5-20P plug, use a single 5-20r receptacle.
The 5-20p has a horizontal neutral blade.
The receptacle is round, about 1-1/2"
 

 
 
Your plasma cutter should have a 6-20P plug (240v, 20a).
Use a 6-20R receptacle.
Horizontal blade on the other side.
Its also round, about 1-1/2".
 

 
You can't put a 5-15 or 5-20 plug into a 6-20 receptacle, and vice-versa.
 
You can get 2-gang plates with two round openings.
search for hubbbell ss72
 
You can also get 2-gang plates with one round and a standard duplex openings.
search for hubbell ss78.
 
Personally, I'd just put in two 1-gang extra deep boxes where I need them and get the stock 1-gang plates at the big box store.
 
 

 

[snakevargas]

I'd guess the welder manual calls for 15amp as it has a standard 15amp plug on the cord. I figured since I was putting in a dedicated outlet, I'd go with 20 amps for future flexibility. I figured I'd go with one of those T-slot receptacles that can take either the 5-15 or 5-20 plug.

The plasma cutter is a curious thing. It has a 120V 5-20 plug but can be used with either 120V or 240V. You'll get better output power plugging it (via an adapter) into 240V. The spec sheet claims it consumes up to 29 amps on 120 or 17 amps on 240.

Physical size of the plugs shouldn't be a problem.

 

[tmbrown97]

Some appliances can accept either voltage - but DO NOT wire up 240V to a 5-20 receptacle!  You need to change out the cord to a proper 240V one.  I'd be willing to bet they sell a specific one, or I've been known to make my own all the time with stuff from Home Depot or if the current cord is adequately rated, you can also cut the end off and put a 240V plug on it.  If you're going that far, I also like using twist-locks for high amperage items.