I have a single 50 amp 240 volt outlet. However, I've been using both my dryer and a welder on this same outlet, both have 3-prong (10-50P) plugs. It can be difficult to plug and unplug cords from this outlet. Are there any ways to share this outlet with both devices with the assumption that I won't be using both simultaneously? Splitter box (with toggle switch)? Splitter cable?

I plan to eventually run a second 240 volt outlet when I have the time and consider this a temporary solution.

  • 2
    Are you in the US (110/220V @60hz) or Europe (220V @50hz), as this will make a difference?
    – Tester101
    Commented Jun 22, 2012 at 16:00
  • Yes, I am in the US.
    – Benzo
    Commented Jun 22, 2012 at 17:08
  • I may have been incorrect. It's likely 240 volt US for the dryer and welder. The connector is a 3 prong plug with 3 flat prongs, I believe the plug is called 10-50P.
    – Benzo
    Commented Jun 22, 2012 at 19:27
  • Apparently after more research, the outlet could be 250v instead of 240. I'll try to confirm this.
    – Benzo
    Commented Jun 22, 2012 at 19:45
  • 5
    The outlet will be rated at 250V, this does not mean you'll actually have 250V at the receptacle. In the US one might say 110V, 120V, 220V or 240V, but they are talking about exactly the same thing since US residential single phase power will range from 110V-125V / 220V-250V. All devices will be rated at the max 125V / 250V.
    – Tester101
    Commented Jun 22, 2012 at 20:41

7 Answers 7


I think for what you want to do:

  1. temporary short term solution
  2. you guarantee you will never operate both the dryer and welder at the same time

You could consider building a 220V 30A power strip. Without knowing your welder, I'll list parts from Home Depot that might work but you have to confirm their suitability for your use.

Please review this chart to determine your plug NEMA type. It will probably be NEMA 10-30 or 14-30. Make sure the plugs, receptacles and dryer cord all match.

NEMA non-locking plug chart
Source: Americord. Click to embiggen.

Note this is for standard 30A dryer. If you need 50A, you will need different receptacles and cord. Probably a range cord. But I assume that since you are currently plugging your welder into your dryer receptacle, 30A will be sufficient.

  1. Raco 2-Gang 42 cu. in. Square Boxes Model # 8257 Internet # 202058366
    You should screw this to the wall if possible for safety, as that will reduce stress on the dryer cord.

    Raco 2-Gang 42 cu. in. Square Boxes

  2. 6 ft.10/4 4-Wire Black Dryer Cord Model # AW20009 Internet # 100672788 Store SKU # 601004

    6 ft.10/4 4-Wire Black Dryer Cord

  3. (two) Leviton 30-Amp 2-Pole Flush-Mount Outlet Model # R50-05207-000 Store SKU # 621336

    Leviton 30-Amp 2-Pole Flush-Mount Outlet

  4. wire, wire nuts, box cover, cord clamp etc.
    If your box can be mounted close enough to the existing outlet, you can cut the excess off your dryer or range cord and use that excess wire to connect the two new outlets. This is just a very minor optimization and you might figure it out as you assembled the box but this way, you'll know before you go shopping.

  • I get the idea, I think I need the NEMA 10-50p connectors, but I'm assuming it would be a similar setup.
    – Benzo
    Commented Jun 22, 2012 at 19:42
  • I like this simple solution.
    – pilotcam
    Commented Jun 22, 2012 at 19:47
  • I like this but it's not a "power strip" (which made me think of a power bar -- something that would allow both connections at once) so much as an adapter. The downside of this is it requires plugging and unplugging a fairly large connector which is not necessarily designed to be plugged/unplugged that many times. Due to the size, there is also a higher risk of shock if you touch one of the large prongs. For this reason, @ppumpkin's solution is safer, but it does really depend on how often the plug is being swapped.
    – gregmac
    Commented Jun 26, 2012 at 17:03
  • 3
    Did you miss the fact that there are two outlets in the box so that both plugs are plugged in and need not be unplugged to use either device? Commented Jun 26, 2012 at 17:30
  • The link to the NEMA plug chart was dead (after 10 years, whoda thunk it?), so I found a new one and embedded the chart in case this one also dies.
    – FreeMan
    Commented May 27, 2022 at 15:32

At first I was not sure what you meant. Basically you only want to use one or the other without plugging in and out.

  • Simple answer is No.
  • Not for home applications.. maybe some commercial or heavy industry ones.. but the plugs are different.

  • Not so simple answer.. You can make one :-)

You will need a highly rated rotary switch like this one (660volt 10A)(220V 30A)

enter image description here

Get a 3 Gang wall box or 3 Gang plug box

enter image description here

Find matching 1 gang or 2 gang plugs

enter image description here

A matching Blanking plate or 2 just in case... because you need to fit the switch in this plate. Using a rotary drill will help get a nice round hole in the plate.

enter image description here

You will need some basic wiring up which should be simple to do.

enter image description here

You can most of this stuff at your local home builder shop. The rotary switch you might need to go to an electrical wholesaler or order from ebay as its not a popular thing kept in stock.

  • 7
    Careful with this solution in the US... you would want a double-pole switch since both legs are HOT (not at earth potential). Would still work, but the switch gives the illusion of zero potential when that is not the case.
    – pilotcam
    Commented Jun 22, 2012 at 19:46

Since you're dealing with a 50 ampere circuit, you'll probably have to look at transfer, or double throw safety switches. You could look for a 3 pole version and also switch the neutral, but I don't think that's a requirement. These devices will likely be quite expensive.

Basically you'll install two NEMA 10-50R receptacles, one for the dryer and one for the welder (Or a NEMA 10-50R for the welder, and a NEMA 10-30R for the dryer). Then you'll wire up the transfer/safety switch "backwards" so that it switches the load, rather than switching the line. Something like this...

enter image description here
Grounding conductors not shown. Don't forget to properly ground all equipment.

Notice when the switch is in the "UP" position, the welder will have power. When the switch is in the "DOWN" position, the dryer will have power. And when the switch is in the middle, power is disconnected from both.


Just use an extension cord with two outlets, as you would with any other outlet:

exteionsion cord

Stores often stock these extension cords next to the generators.

Your circuit breaker will ensure that you don't overload your circuit, even if you should happen to use both devices at once.

  • 1
    I havn't been able to find any Y-cables that support the 10-50P connectors.
    – Benzo
    Commented Jun 22, 2012 at 19:40
  • 1
    @Benzo I doubt that anyone makes them. Which means this answer is useless. Commented Jun 26, 2012 at 15:57
  • 2
    On the other hand, you could deploy slightly higher than average human intelligence and ingenuity, cut one of those connectors off and put a 10-50P connector on, presuming this is made out of at least 6 gauge wire. And the breaker will protect the wire. Commented Jun 7, 2015 at 4:59

The problem with the solution is: The circuit breaker serves to protect the wiring between the switchboard and the appliance. A 50A circuit breaker does not protect the 30A dryer cable when a short circuit is in the dryer or dryer cable, so the dryer cable or the dryer could burn up if the short circuit draws just 45A. The code requires you to insert a 30A or smaller circuit breaker or fuse between the 50A circuit and the 30A receptacle.

  • The dryer power cord is assumed to be protected by being applied within the dryer's Listing as per 240.5(B)(1). Commented Feb 8, 2017 at 2:48
  • @ThreephaseEel in other words a 30A dryer with #10 wire, fed by a 60A breaker, using listed extension cord is permitted?
    – Kris
    Commented Feb 8, 2017 at 12:12
  • @Kris -- by the strict letter of the NEC, yes. (How is it different from the 2A cord on my laptop power adapter with 20AWG wire in it, fed by an 18AWG extension cord, all plugged into a 20A circuit/20A breaker?) Commented Feb 8, 2017 at 12:35
  • The main difference is the wire in the wall is protected by the correct size breaker
    – Kris
    Commented Feb 8, 2017 at 12:57
  • 1
    @Kris -- I understood your statement to mean that the cord was 10AWG, not the branch circuit wiring -- the branch circuit wires are covered under 240.4 which requires an appropriately sized OCPD, of course. Commented Feb 8, 2017 at 23:16

I know this is an older post but I was looking for the same thing to run my air compressor off the same outlet (though not simultaneously) and after an hour on Google I found this:


I think this is what you were looking for though for the 10/50: http://www.rakuten.com/prod/high-tide-125-250v-50-amp-male-to-2-125-250v-50-amp-female-y-adapter/297099895.html?listingId=519631289&sclid=pla_google_Boaters+Plus&adid=29963&gclid=CK20y-DTg9ICFROUfgodYygPWA


A simple two position contactor makes everything happy. It can be controlled with 12 to 120 volts, at 50 amps, the contactor would still be relatively small, stick it in an 8 by 8 by 4 box, and just to make to keep the user honest add a wind up timer of say 60 minutes. It's like a transfer switch, it can be either, or, but not both.

I'm out of the loop on pricing, but a few years ago this contactor would be $125.00 US, a box for 15.00, wind up timer for 12.00, and maybe 90 minutes to assemble and test. By the way the first thing that wears out is the timer(I built 11 units like this, that run about 15 hours a day), I built them in 2003, one timer has died.

  • Can you add some details as to how you did this? Maybe an image or two?
    – Machavity
    Commented Jan 25, 2018 at 18:35

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