220v electrical question

[Ron Bott]

I'm working on a wiring diagram for my new shop setup. I have two pieces of equipment that run on 220. My tablesaw & jointer/planer. Is it possible to have a dual outlet for 220v plugs like that of a standard 110v outlet? For example I can plug the J/P plug into one receptacle and the tablesaw into the other. Obviously they would not both be running at the same time.

[Lee Schierer]

From a code standpoint, I don't think that is allowed because someone could run both at the same time and overload the circuit. I know people have done similar things in their one man shops.

[Mike Henderson]

I'm not a code expert, but I believe it is allowed to have multiple 220V outlets on a single circuit. But you're probably not going to find a duplex outlet - you'll probably have to use two boxes.

If duplex outlets exist, someone will post a pointer to them. And one of the code experts will post soon on the code aspects, I'm sure.

Mike

[Rob Russell]

Ron - what you want to do is fine.

Lee - there's nothing in the code that would prevent that. As long as the breaker is sized to protect the conductors, you can generally plug as many loads into the circuit as you want. If you try to pull more current than the circuit is sized for, the breaker will simply trip.

You should be able to find a duplex 240v outlet at a big box store. If not, any electrical supply house will have them.

[Ken Higginbotham]

I would think an over/under set of outlets would/could cause an issue getting the plugs in because of the cords. Maybe a side by side of single outlets would be a better idea - ?

[Rob Russell]

I would think an over/under set of outlets would/could cause an issue getting the plugs in because of the cords. Maybe a side by side of single outlets would be a better idea - ?

Unless you're using twistlocks - why? The standard 240v plug is the same basic size as a regular 120v plug - it's just that the flat pins are configured differently.

It'd be like plugging in 2 routers to a 120v duplex receptacle.

[Ken Higginbotham]

Some plugs have the cord that comes straight down. If you plugged one into the top outlet it'd block the lower one wouldn't it?

[Keith Burns]

McMaster-Carr.com has the duplex outlet. Just got one. About $16. Part No. 7120K34

[Rick Moyer]

Some plugs have the cord that comes straight down. If you plugged one into the top outlet it'd block the lower one wouldn't it?
Yes , 'some', usually referred to as an air-conditioner plug, but for my shop I use the one's that Rob refers to.

[Ken Higginbotham]

Am I missing something? If you have this:

http://www.mcmaster.com/param/images/nema/7120k34-180x200.gif

And both of your plugs look like the one on the right:

http://www.mcmaster.com/param/images/nema/plugtype_90degreemale.gif

You won't be able to plug them both in will you?

I suppose as long as you knew one would always come straight out you'd be ok...

[Chris Padilla]

All the twist-locks I have (L6-30) come straight out.

[Bill Stoffels]

to have aduplicate plug you have to increase the wiring for the two from a 12 to a 10 or 8 if there the same as the 110v plugs.
I have added wo boxes in my shop and it seems to be the best set up .
No plug end issues " trying to plug two in at the same time "
Or as Chris has said just run the twist locks
Bill

[Rob Russell]

Ken,

I understand your point now and, yes, if both of the plugs are right-anple plugs - you've got a problem.

Bill,

Why do you say that the wiring gauge has to be increased? Let's say you've got a 240v/15A circuit with the duplex receptacle pictured in Ken's post. Plug a machine into each of those outlets. Try and run more than 15A worth of machinery at the same time and the breaker will trip.

If your thought is that you'd run #10 and a 30A breaker so you could run both machines at the same time - that IS a code violation because you can't have 15A/20A receptacles on a 30A circuit. A 30A circuit requires a 30A receptacle. Refer to 210.21(B) in the NEC.

[Rob Russell]

All the twist-locks I have (L6-30) come straight out.

Yabbut I've never seen a duplex twistlock receptacle. Any twistlock I've ever seen is a single receptacle. There are multi-gang plates so you could have multiple twistlocks in 1 multi-gang box. Here's a picture of a Hubbell plate (15A twistlocks).

[Ken Higginbotham]

Here's a picture of a Hubbell plate (15A twistlocks).

Now you're talking - :)

(I have to be careful on these kinds of things as I have been known to stick my foot in my mouth a time or two :o )

[tody Brock]

I have dual 220v in my shop. One for my tablesaw and one for my air compressor. I just mounted 2 boxes side by side and ran jumpers from one box to the other. I t works fine.

[Chris Padilla]

Yabbut I've never seen a duplex twistlock receptacle. Any twistlock I've ever seen is a single receptacle. There are multi-gang plates so you could have multiple twistlocks in 1 multi-gang box. Here's a picture of a Hubbell plate (15A twistlocks).

Good point...all my 240V/30A receptacles are single so the right-angle, straight issue is kind of a non-issue with multi-gang. In fact, the right-angle is likely less stressful on the cord. I just don't recall ever seeing any right-angle L6-30s....

[Chip Lindley]

Duplex 220V recepticals limit you to 15A, from what I could find in a quick search.

I LOVE OVERKILL! I use Hubbell L6-30 twistlock connectors on all my 220V machines. I can only use one machine at a time, so (8) single outlets are on the same circuit around the shop walls for jointer, planer, two shapers, two DPs, RAS and drum sander. circuit handles anything up to 5hp. The DC, RPC and Compressor are on separate circuits.

[Tom Veatch]

NEMA 6-20R duplex are available. For example (http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?sitex=10021:22372:US&item=3386).

[glenn bradley]

Am I missing something? If you have this:

http://www.mcmaster.com/param/images/nema/7120k34-180x200.gif

And both of your plugs look like the one on the right:

http://www.mcmaster.com/param/images/nema/plugtype_90degreemale.gif

You won't be able to plug them both in will you?

I suppose as long as you knew one would always come straight out you'd be ok...

Correct but you don't have to use those type of plugs.

[Bill Stoffels]

here in Illinois you can run 2 boxes but they have to be seperate circuts as you noted . I did not want someone to think that the 12 ga wire could support 2 units running at the same time .
Whwn I got my MM16 there real clear about running a committed 20 amp 220 v circut for it not a 15 amp with #12 wire min.

Just trying to ensure some one does not put them selves in a predicament

Thanks for the clarification.

Bill

[Rod Sheridan]

Type 5492 duplex receptacles are available (20A 240V).

My shop uses multiple duplex 15A 240V receptacles fed from a 15A breaker since I don't have any machines larger than 3HP, except for my jointer/planer which has a 4HP S6 motor.

The two 3 HP machines have high power factor/high efficiency motors with an FLA of 12.5 Amperes.

Regards, Rod.

[Rick Christopherson]

Duplex 220V recepticals limit you to 15A, from what I could find in a quick search.No. The same rules that apply to 120 volt circuits also apply to 240 volt circuits. You are permitted to install a 15 amp duplex receptacle on a 20 amp circuit. (NEC Table 210.21 (B)(2))

[Sonny Edmonds]

What I did in my shop was to bring the 240 volt, and a 120 volt (4 plex) outlets to the front of my saw. I also brought a 4" dust collection gate under those.
Now when I want to plug in any roll-up equipment to use, all the amendities are right there for whatever it is. 120 volt or 240 volt, DC, and also a compressed air hose.
I unplug my TS, and plug in the BS or joiner to my 240 volt circuit. For my planer it plugs into the 120 volt circuit.

And it makes it a no brainer to unplug anything before I stick my finners anywhere near sharp spinning steel. :)