Switch Selectable Box with Two Twist-lock Receptacles

[Joe Hollis]

Hello,

I have three single-phase 240 volt machines that are equipped with twist-lock plugs, but only two wall receptacles. Is it possible to properly rig up a wooden box with two twist-lock receptacles in it so I can leave two of the machines plugged in to the box at all times, the cord running from the box plugged into the wall receptacle, and then use a switch mounted on the box to select either one tool or the other?

I don't want to risk damaging any of the tools, but I do not have the mobility I used to, and it's really hard for me to access the wall receptacle to change the machine that is plugged in there.

Thanks,

Joe H.

[Dan Friedrichs]

...I'm confused. Why is the switch required? You only use one machine at a time, right? If you had 3 receptacles, wouldn't you just plug all 3 machines in and leave them plugged in all the time?

Just buy one of these?
https://www.amazon.com/dp/B00SJESLEG...JESLEG5502514/

[Joe Hollis]

Hello Dan,

I only have two wall receptacles, but three machines, so when I want to use the unplugged machine I have to access the wall receptacle and swap.

There is not enough capacity in the electrical panel (so I have been told) to add another circuit. I would like share the one receptacle by using some sort of switch arrangement if I can.

Regards,

Joe

...I'm confused. Why is the switch required? You only use one machine at a time, right? If you had 3 receptacles, wouldn't you just plug all 3 machines in and leave them plugged in all the time?

Just buy one of these?
https://www.amazon.com/dp/B00SJESLEG...JESLEG5502514/

[Mark Kanof]

I think what Dan is suggesting is to have one machine plugged into one of your wall receptacles and the other two machines plugged into the y-splitter that he linked to. Then that splitter would be plugged into the second wall receptacle. That way all three machines would always be plugged in. As long as you do not turn on both of the machines connected to the splitter at the same time, you should not have any problems.

[Dan Friedrichs]

I think sometimes people have a difficult time seeing 240v circuits the same way as they see 120v circuits, but there are no special/different "rules" for 240v. Much of the world uses 240v in the way we use 120v in the US.

So: if you had 3 tools that ran on 120v, but only a "regular" duplex 120v receptacle (2 positions to plug into), what would you do? You'd just buy a power strip or splitter to turn the 2 positions into 3 or 5 or 6...

That's exactly what you need to do, here But just a power strip / splitter with 240v plugs+receptacles on it.

[Rod Sheridan]

Hi, just add a third receptacle in parallel with one of the existing receptacles.

I only have one 240V circuit that feeds all may machines, and a separate 240V circuit for the cyclone...............Regards, Rod.

[Joe Hollis]

Sorry Dan, I misunderstood,

Thanks a lot for this. I will order one of those cables.

Regards,

JH.

I think sometimes people have a difficult time seeing 240v circuits the same way as they see 120v circuits, but there are no special/different "rules" for 240v. Much of the world uses 240v in the way we use 120v in the US.

So: if you had 3 tools that ran on 120v, but only a "regular" duplex 120v receptacle (2 positions to plug into), what would you do? You'd just buy a power strip or splitter to turn the 2 positions into 3 or 5 or 6...

That's exactly what you need to do, here But just a power strip / splitter with 240v plugs+receptacles on it.

[Carlos Alvarez]

I'm about to do something like this because I have one 240v outlet. It feeds the nearby compressor, welder, and plasma cutter. OR I can plug in a 20' #10 SJ cord which runs outside to the shop space ten-ish feet away. That powers all the wood tools. I'm going to either just change out the box to two-gang and put another outlet in it, or build a pigtail to take the single connection and make two. I have the parts for all these options sitting around. Now in MY case, I might want a switch or something because the compressor is a true 5HP, using a measured 4000 watts, so there's not enough left for most of the other tools. Or I just have to remember to turn off the compressor's own switch.

Or I could stop being lazy and put in another 240 circuit. The main panel is directly behind the existing plug, just poke in and add breakers.

[glenn bradley]

I have daisy-chained a second receptacle off of one I put in during a shop remodel. I plug two unrelated machines in that are never used at the same time and have never had an issue.

[James Biddle]

My guess is the reason you want to build one is that you could not find a 240 Wye-splitter cable here in the US. I suspect it's because most 240 circuits here are considered dedicated and the UL listing for such a Wye is not possible. That said, what you're looking to do already exists, but buying a manual transfer switch would be cost prohibitive from your post. Having a qualified electrician add another receptacle to the existing circuit is the recommended procedure, because the supply wires and breakers need to be evaluated prior to expansion. Yes, many here will give you advice to go ahead, but it's not advice that takes into account your particular home. I think someone named Julie posted something about taking online electrical advice with skepticism...that was good advice.

[Dan Friedrichs]

James, the Amazon link I posted above is a UL-listed 240v wye splitter...

There is nothing about 240v that requires dedicated circuits. Much of the world uses 240v for general-purpose convenience use the way we use 120v. Nothing to be skeptical about

[James Biddle]

I stand corrected about the splitter, but I still don't think it's a good idea to seek electrical advice here. Also, it's because we use 120 as our general purpose voltage that makes our 240volt circuits more unique and typically dedicated, unlike the rest of the world.

James, the Amazon link I posted above is a UL-listed 240v wye splitter...

There is nothing about 240v that requires dedicated circuits. Much of the world uses 240v for general-purpose convenience use the way we use 120v. Nothing to be skeptical about

[Carlos Alvarez]

I never even thought about buying a splitter, simply because I have the parts and knowledge to make my own. But then I realized that I think I may have some down in one of the server rooms, unused, because they aren't uncommon in that environment.

[Don Bullock]

I have one 220 floor plug. My jointer and table saw needed to be plugged into it. The “Y” connector that Dan linked to works perfectly since I only run one machine at a time. It’s good quality as well.

[joseph mansker]

I don't disagree with James on his point regarding electrical advice if you do not do further research. Most building codes require separate circuits for 240v applications such as your dryer, electric range/oven, water heater, etc. Even your circuits for your refrigerator, freezer and dishwasher are dedicated circuits although they are normally 120v. I use dedicated 240v circuits in my shop because its my choice to do so and its good practice. Although, I have to say that I rarely have two machines running at the same time. But I am a conservative guy. Safety first.
Joe