220V question: sharing an outlet

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Forum topic by Elizabeth posted 04-02-2013 05:52 PM 6981 views 0 times favorited 61 replies Add to Favorites Watch
View Elizabeth's profile


823 posts in 4199 days

04-02-2013 05:52 PM

Topic tags/keywords: question electricity 220v

Question for you electricians out there.

I have four 220v outlets in my shop – one came with it when I got the shop and the other three were put in by an electrician last year. All are being used by machines right now – table saw, 14” bandsaw, jointer and dust collection. The plugs for the table saw and bandsaw are located right next to each other, on the ceiling near the middle of the shop.

I am adding an 18” bandsaw to my shop next week. It needs a 220v outlet. I am planning on locating it next to my 14” bandsaw and sharing the dust collection ducting. I don’t yet know if I will run permanent ducting to each saw or just share it back and forth with some leftover Dust Right pieces that I have. I will also need to share the power outlet, but it’s on the ceiling.

My question for the electricians: If I am only ever using one of the machines at a time, can I plug both machines into the same 220v plug using some sort of adapter? 110v outlet adapters are common enough but I don’t know if there might be a safety reason for not doing the same with 220v.

61 replies so far

View Grandpa's profile


3264 posts in 3731 days

#1 posted 04-02-2013 05:59 PM

I see no reason you couldn’t share. The cheapest thing would be to jumper a wire of the correct guage from the plug you currently have into a remodeler’s box. These are easy to attach to the sheet rock. You would have to remember that the sheetrock is all that supports the box and it WILL break if you pull too hard on the plug. you could attach the box to a joist with nails and it would be sturdier. If you buy components and make a wye you have to buy more parts. This could be done though. You can only run one saw at a time and it should be protected by a breaker of the correct size. what is the new saw??

View Elizabeth's profile


823 posts in 4199 days

#2 posted 04-02-2013 06:01 PM

A Rikon 18”, at a great price in the current Woodcraft sale :D

ETA I’d probably be more comfortable building a wye (if it is what I think it is; any clarification?) than cutting holes in the sheetrock. I did build a 220v extension cord for my table saw, as the cord wasn’t long enough to reach the ceiling, and rewired my 14” bandsaw for 220 (because it was the only way to get it to ANY plug without draping an extension cord halfway across the shop) so I have a little experience wiring plugs, but no experience cutting sheetrock or installing boxes. Also the ceiling is less accessible now than it was a year ago, because the dust collection ducting is running near to that area and there’s a big table saw in the way of where I’d need to place the ladder.

View LeChuck's profile


424 posts in 4118 days

#3 posted 04-02-2013 06:16 PM

I am not an electrician, but in my workshop I went from a single 220V outlet to 3 of them on a single 40A line. That is because I am absolutely sure that there will never be more than one machine (table saw or bandsaw)+dust collector on at the same time and the circuit is sufficient for that.

That said, if I were you I would rather not use a plug adapter or doubler, but simply branch out (with proper size wires) and add an extra surface outlet on the wall for a more permanent connection. I posted on this before when I was doing my connections and I think there are some photos too.

-- David - Tucson, AZ

View Fred Hargis's profile

Fred Hargis

6926 posts in 3548 days

#4 posted 04-02-2013 06:18 PM

I’m not an electrician so you may want to skip this reply. But I have 2 240V tools running off the same outlet. I used a shop built extension cord that goes first to the jointer, and then extends on to an RAS. I just used handy boxes and 240V outlets to make the extension (it’s #12 wire).

-- Our village hasn't lost it's idiot, he was elected to congress.

View Swyftfeet's profile


170 posts in 3227 days

#5 posted 04-02-2013 07:29 PM

I’ve never understood all the angst surrounding 220v machinery and wiring, all of Europe and GB runs everything on 220V. If you do not overdraw current on the breaker and use properly gauged wire, you’ll be fine.

I guess the fear might be related to the fact that households in the US only use 220 for specialty(dryer, stove, welder, compressor, hot tub ect) devices and generally have a single breaker per outlet that is designed to pop when that particular machine overdraws.

-- Brian

View Elizabeth's profile


823 posts in 4199 days

#6 posted 04-02-2013 07:34 PM

Brian, my angst is equal opportunity. I have mechanical engineering experience but no electrical beyond one term of circuit theory. 110v makes me nervous too!

View Swyftfeet's profile


170 posts in 3227 days

#7 posted 04-02-2013 07:55 PM

I certainly wasn’t trying to single you out. It’s just kinda entertaining(darkly) to me that in general folks will run 90 billion xmass lights, a cubical heater, and a computer, and a thousand other things on household extension wire off a single outlet, but when you talk 220 they wouldn’t touch it with a ten foot pole.

Probably good now that I think about it…

-- Brian

View DIYaholic's profile


19921 posts in 3730 days

#8 posted 04-02-2013 07:58 PM

Thanks for asking this question. I’m in the same boat….

I have 2-single 220V receptacles, but too far from my machines. I was looking at an extension cord arrangement, but will now consider extending the circuits with multiple outlets.

Gotta love the sharing of knowledge and exchange of ideas that transpires, here on LJs!!!

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

View Oldtool's profile


3196 posts in 3246 days

#9 posted 04-02-2013 08:07 PM

You can do with 220 volt circuits the same you would do with 120 volt circuits, provided you ensure to use proper materials – those components or materials that meet the safety standards for use on 220 volts.
Since almost everything used in 120 volt circuits is actually rated for 600 volts as a safety factor, you should have no problem with the voltage issues. Current is the second issue, just make sure the plugs or sockets, and / or wires you use are rated at – or higher than – the circuit breaker on this feed. The one thing you must ensure is that the wire or plug / socket does not have a lower amperage rating than the breaker or the machine it’s used for, or there exists the possibility of creating heat and possible fire. The S/N nameplates on the machines are code required to show maximum amperage draw under load.
If I were doing this, I’d go to big box, get a metal box, a 220 V plug, two 220 sockets, some wire to match the breaker and machine serial number plates, make a short extension cord to go from the wall socket to the two machines – with both plugged into the new junction box with the two new sockets.
Hope this helps.

-- "I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The point is to bring them the real facts." - Abraham Lincoln

View Carl Webster's profile

Carl Webster

82 posts in 3853 days

#10 posted 04-02-2013 08:14 PM

Adding an additional 220/240 volt receptacle in parallel to an existing 220/240 Volt receptacle is no different in principle to doing the same with a 120 volt receptacle. As long as the wiring is the same size and protected by the proper circuit breaker, you will be fine.

-- Carl in SC

View Swyftfeet's profile


170 posts in 3227 days

#11 posted 04-02-2013 08:18 PM

I should specify advice in this thread will work but may not follow local building code. If you do this and in the future decide to sell the house, be prepared to undo it.

-- Brian

View Swyftfeet's profile


170 posts in 3227 days

#12 posted 04-02-2013 08:30 PM

And if a fire breaks out and they find it due to electrical you’ll likely be footing the bill if it’s not wired to code.

I simple interlock that branches the legs of the circuit so only one of them is getting juice would likely cover the code issue, but you should call the electrical inspector to CYA.

-- Brian

View JamesT's profile


104 posts in 2967 days

#13 posted 04-02-2013 08:32 PM

Oldtool has a good suggestion. As he points out it’s the size of the wire that’s important. Many people don’t understand that the main purpose of a circuit breaker is to protect the wiring from overheating and catching on fire. Not to protect the equipment plugged into the circuit.

-- Jim from Horseshoe Bend

View crank49's profile


4032 posts in 4026 days

#14 posted 04-02-2013 08:36 PM

According to the NEC (National Electric Code) two or more motors are permitted on a single branch circuit if each motor has its own overload protection.

Of course you can provide an outlet near the saws at operating height that is on a cord plugged into the ceiling outlet. Then, to be correct by the code you would only plug in one saw at the time.

Multi-motor connections on shared circuits are generally permitted only if the motors are under 1hp.

I haven’t dug through the whole code on this and there may be exceptions, but I generally just put a fused disconnect on each machine and then they can both be wired together.

View 404 - Not Found's profile

404 - Not Found

2544 posts in 4024 days

#15 posted 04-02-2013 08:43 PM

Not really qualified to answer this question being in Europe, but couldn’t you replace your outlet with a double receptacle? You’ll find them on Amazon.

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