Can I share a 240V outlet between two devices?

Question

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.

Answer 1

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.

^{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.

   

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

   

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

   

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.

Answer 2

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)

Get a 3 Gang wall box or 3 Gang plug box

Find matching 1 gang or 2 gang plugs

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.

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

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.

Answer 3

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...

^{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.

Answer 4

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

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.

Answer 5

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.

Answer 6

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:

https://www.amazon.com/gp/product/B00SJESKC4/ref=ox_sc_mini_detail?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

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

Answer 7

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.