i have two welders and one plasma cutter all 220 volt @ 50 amps. I would like to run a cable to a welding table and have a way to switch power to three different outlets on the table. Only one unit powered at any time. Can some tell what switch use?

  • Folks, I know in the past we figured out it is not prohibited to have multiple sockets on a 30A circuit. Is that also true of 50A? – Harper - Reinstate Monica Jun 28 '18 at 1:59
  • @Harper -- the situation with 50A multioutlet branch circuits is more complicated, as 210.23(C) restricts them to fixed cooking appliances in the dwelling unit context. (Outside of a dwelling unit? Have at it!) – ThreePhaseEel Jun 28 '18 at 3:14
  • Are you the only person using this work space or is it shared? – paul Jun 28 '18 at 20:39
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    I agree outside a dwelling unit this would not be a problem. If within a connected garrage set up a 50 amp sub fed from your main breaker then have 3ea 50 amp Breakers in the sub each would be on its own breaker so there is no code conflict as the 50 amp main would trip if 2 devices were used at the same time. – Ed Beal Jun 28 '18 at 21:05
  • Thanks for all the ideas. I am the only one in the shop just want it correct. Dummy proof. – Bill Rabey Jun 29 '18 at 1:25

If you are trying to connect switches to three different outlets the easiest method I can think of is mount a sub panel closest to the receptacles and connect each receptacle to a different 50A breaker. I think trying to find and purchase a heavy duty 240V/50A 3 position switch would probably be a little out of a DIY price range, as it is an industrial piece of equipment.

Hope this helps

FYI - From a commercial standpoint you can connect 50A receptacles together on a single circuit. I have done but the AHJ made us label each receptacle that only one receptacle could be used at one time.

  • That is what I’m trying to do. I don’t want to be able to have more than one at a time. Dummy proof – Bill Rabey Jun 28 '18 at 20:26
  • I like this idea. If you keep everything off except when you'll use it, it would be hard to forget. If you have to go to the panel to switch devices you're going to remember to turn the other ones off, especially if you tape a note on a flap over the breaker stack. – isherwood Jun 28 '18 at 20:44
  • Since you mentioned it, my other thought was to use three two-way switches in a series/parallel arrangement. I'm not sure what type of switch is appropriate, though, and three switches might cost as much as a single three-position switch anyway. – isherwood Jun 28 '18 at 20:45
  • Do breaker interlock switches exist for more than two breakers? I know they make these for panels fed by generators and the grid but only for two breakers. – Hari Ganti Jun 28 '18 at 21:01
  • Wish I would have read this before commenting, however a 60 amp 12 position panel could be used after looking, that's what I used and it was not expensive, I did this in my last home / shop detached and it was approved and there is a green tag and sign off on the building. If attached we would need to double check and verify local codes. – Ed Beal Jun 28 '18 at 21:12

What you want is called a "3 step cam switch", they are available up to about 200A as far as I know, 63A is a very common size available all over the world.

One of the biggest mfrs, their products are sold under several other big names, but they are the actual mfr. http://www.krausnaimer.us/Countries/USA/en/Control_Switches/control_switches.html

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