As requested - Pics and more info on my outlet setup

I apologize for dragging my feet on this. I've been asked a few times to provide pics and more info. Finally have a few minutes this morning.

So here's the setup:
-32x40x12 garage
- 2 x 20A 240V circuits power all of the "general duty outlets". Each circuit powers 1 half of the garage.
- 120V Outlets are all split-receptacle meaning the top outlet and the bottom outlet are each on their own 20A leg. Each outlet box can provide a total of 40A at 120V
- Outlet boxes are placed every 6' along the wall.
- Every 2nd outlet box is a double wide and contains 240V receptacles in addition to 120V. The 240V receptacles can provide a total of 20A at 240V.

Here's a pic:


This was done about 3 years ago now. It's worked very well. I've never tripped a breaker. The 240V outlets have been super handy for powering my Millermatic 180 welder and Hypertherm 30XP plasma cutter. Technically the miller needs 22A but hasn't tripped yet. I installed welder plugs all over the garage and have yet to use them.

If I was to do it again, I'd switch things up a little. While there is plenty of power, I find myself placing outlet splitters in some locations. Instead of doing a double box every 2nd outlet, I'd do a double box every outlet and the boxes that didn't get 240V receptacles would get 4x 120V receptacles.

Nice.

I don't know why, but every time I see the 20A 240v receptacles, I always think they are a 20A 120V receptacle winking at me...

Jim

Thanks. I agree - they're odd to look at. Especially when beside a 20A 120V receptacle.

Least you understand what it is! I've often got visitors trying to plug 120V tools into the 240V receptacles and scratching their heads. Not many 20A 240V outlets around these parts.

May be code but way too easy to mix up.

I would have separate boxes for 120 and 240. There would be different kind of plates with different finishes and big bold labels.

Bill

Not sure how you are getting your GFCI protection for your 120v receptacles if you are sharing the 2 hot legs with the 240v plugs?

bczygan said:

May be code but way too easy to mix up......Bill

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How is it easy to mix up? The different design layout of the receptacles makes it impossible to plug in the wrong type of device into either one.

A 120V 15 or 20 amp device will not be able to plug into the 240V receptacle due to the blades on the 120V plugs having a different layout, and vice versa.

The only possible way for someone to mix it up would be for that person to physically take a pair of pliers and twist one of the blades on a power cord to try to make it miss-fit into the wrong receptacle.

If they do that, then, well, they just don't have any brains.

Having them in separate boxes would be nice though, as you could add more of the same type of receptacles in each box, as the OP said he will probably do if he has to run more receptacles around the shop.

Jim

CJ7VFR said:

How is it easy to mix up? The different design layout of the receptacles makes it impossible to plug in the wrong type of device into either one.

A 120V 15 or 20 amp device will not be able to plug into the 240V receptacle due to the blades on the 120V plugs having a different layout, and vice versa.

The only possible way for someone to mix it up would be for that person to physically take a pair of pliers and twist one of the blades on a power cord to try to make it miss-fit into the wrong receptacle.

If they do that, then, well, they just don't have any brains.

Jim

Click to expand...

It's not that you could actually plug it in wrong. It's the fact that visually, they are so similar as to be confusing, causing momentary difficulty.

Clear visual differences including color, shape, size and physical separation help with efficiency. We use visual cues.

In my shop, the 120V 20A duplex outlets have white plastic cover plates. The separate 240V 20A receptacles are single round ones with SS cover plates.



Bill

I thought it was against code to put 120 and 240 in the same box. When I wired my shop I used 2 120 circuits in each box and an electrician buddy of mine told me to make sure they were off the same leg so there wouldn't be 240 in the box.

RWorth said:

I thought it was against code to put 120 and 240 in the same box. When I wired my shop I used 2 120 circuits in each box and an electrician buddy of mine told me to make sure they were off the same leg so there wouldn't be 240 in the box.

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Right or wrong I have quad boxes with dual duplex outlets in my garage. They are each served with 12/2 and on a 20A breaker (120V). Breakers side by side in panel. No shared neutrals. I have thought about tieing the handles on the breakers but have not yet done so. Conceivably one could get 240V out of the quad box if hacked.

RWorth said:

I thought it was against code to put 120 and 240 in the same box. When I wired my shop I used 2 120 circuits in each box and an electrician buddy of mine told me to make sure they were off the same leg so there wouldn't be 240 in the box.

Click to expand...

Nope. Actually, it's against code to NOT do it in some circumstances. Kitchen counter plugs for example. Code calls for split receptacles.

bczygan said:

It's not that you could actually plug it in wrong. It's the fact that visually, they are so similar as to be confusing, causing momentary difficulty.

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Doesn't happen for me. All of these boxes have the 240V receptacles on the right side. I don't even look, I just know Left is 120V right is 240V. Guests may struggle momentarily but I rarely have them and who cares about a guest taking an extra 30 seconds once in a blue moon anyway.

In fact - I think it would make things worse by moving to separate boxes as they'd still look the same. I would also have to do something like mount at different heights or use a colored faceplate.

Its a non-problem for me. If it was a problem, I'm confident I could find a way to visually make these outlets that didn't involve a separate box.

ForceFed70 said:

...Its a non-problem for me. If it was a problem, I'm confident I could find a way to visually make these outlets that didn't involve a separate box.

Click to expand...

Maybe turn one dual receptacle upside down? Then at least visually they would appear different. I would probably turn the 240V ones upside down myself.

Jim

Since any of those receptacles can be mounted either way, that wouldn't really distinguish them to me. If they were mine I'd use a different color somewhere, or have the 240V be a single receptacle. After all, how many 240V things are going to be plugged it at once?

http://www.kyleswitchplates.com/duplex-receptacle-with-single-1-4-inch-round-outlet-cover-plates/

In the trade show industry we use a double sided box that has 2 duplex receptacles in it. We use 120/ 208v 3 phase power on a 5 wire tail. On one side is a 20a duplex with the first 2 phases of 120v with the hot tab broken. On the other side of the box is a combo 120 and a 20a 208v plug in. The 208v plug shares the 2nd and 3rd phase with the other plugs but it's not an issue for us since we all know how to use these boxes. Sometimes we cover the shared 120v openings if we need the full load at the 208v plug so we don't overload the feed but rarely cover the 208v opening if not needed since the customer can't use it without the correct cord anyway. Not a big issue for someone who is familiar with the different style of cord caps. If it doesn't fit it won't plug in.
On a separate note, there is a great app that I use a lot at work to help mate up a customers cord cap with our various 5 wire adaptors. We use a 30a, 120v/ 208v 5 wire cap on almost all of our equipment and this rarely matches the customers equipment. We have various adaptors available and I use a NEMA app to find out the NEMA code of the customers cap to see if we have the correct adaptor so we don't have to cut off or otherwise remove their cap. Just do a search under NEMA in the app store. The one I use is by Summit Electric.