Adapter 240V 50A to 120V30A (and 120V 20A)

No fries

No fries

Well-Known Member
Joined
Mar 31, 2005
Location
Fort Mill
My Garage is underpowered for what I use (240V Welder Compressor are good) but the 120V side I really would like a couple 20A circuits. (30A bonus) Everything is 15a and the box is full so I can't add anything that I'm aware of. My thought is to use one of my (2) 240V 50A plugs and make an adapter that has an 120V 30A plug (For our Camper) and a standard 120V 20a or a couple 15A plugs for grinders, 120V welder, Portable 120V AC unit Etc. Can this be done without burning down the house/garage?

I usually pull the AC off the garage door outlet since it seems dedicated and not much else is on the circuit, however I can't run the AC and a grinder or 120V welder or a chop saw on the circuit. I've got to the point twice now that the breaker has gotten so hot that it won't stay on when the AC kicks on nothing else on that circuit that I'm aware of is running. Forgot to turn off the AC when using Chop saw or welder. So I've replaced the breaker three times now in the past 5 years and I'm wondering about options and hoping the adapter could be the easiest solution. Only time I ever use both 240V 50A is when the plasma is being used, otherwise I have one that I'm hopping to tap into for the more common 120V high draw items I use.

I have 2 of these receptacles

50a Weld.jpg
I'd like an "adapter" for these, Maybe just mounted to a small piece of plywood
Quad.jpg30A RV.jpg


Anyone know if it can be done with the two 120V legs from the 50amp?
 
possible - abolsutely
safe - yes 'ish'
code compliant - doubtful

UNLESS you were to use the feed for the 240V 50A and install a load center in its place and then wire some branch circuits off the load center.
 
You would be using the ground as a neutral which is far from ideal. You'd also have those outlets on a 50a breaker unless you changed it out. Is the panel in the garage or is it somewhere far away?
 
Panel is in the garage above my bench so it is "easily" accessible.

I forgot about the neutral wire, And since there isn't a neutral it shouldn't be done I assume. There is a sub panel but I was told I can't add to that either.

I know more than your average Joe but by no means completely understand it all.
 
Without seeing what you've got going on, I'd say buy two mini tandem breakers to put 15a circuits on and free up 2 spots for a 30a 120 and 20a. If the panel is right there you could surface mount some conduit and a couple quad boxes then run your new circuits and outlets.
 
I can take a picture later when I get home unless I can find one on my phone, but most if not all of the spots already have 2 mini breakers installed.
 
Ron said:
possible - abolsutely
safe - yes 'ish'
code compliant - doubtful

UNLESS you were to use the feed for the 240V 50A and install a load center in its place and then wire some branch circuits off the load center.
Click to expand...

That's the same conclusion I came to. I have the same NEMA 6-50R plug for my welder and would like to be able to plug in my camper and run the AC.
 
There is always this option. It should fit in a Square D QO panel. Technically, it doesn't fit in a Homeline panel either but it can be made to work. (yeah, don't ask) It's a Siemens QT breaker.
Breaker.jpg
 
Ron said:
possible - abolsutely
safe - yes 'ish'
code compliant - doubtful

UNLESS you were to use the feed for the 240V 50A and install a load center in its place and then wire some branch circuits off the load center.
Click to expand...

This is what I have done in the past. Installed a small panel that was fed by the 240v circuit, and added a few 120v circuits off it.
 
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