220 Receptacles - 20 amp?

[Michael Mahan]

You need to add a sub panel & quit messing around trying to cram more breakers into that main ,
your electrician pooched you , he had that panel already as a left over from another job or it's a used panel .

these guys do that all the time .
adding a sub panel really is not that expensive

[Ryan Mooney]

The narrow tandem breakers are mostly fine - if your panel supports them. Most of the GE panels only support that type in the bottom half of the box, look up the docs for your specific panel to make sure which slots have the proper connectors for tandem breakers (not all GE panels support them but most do - I'm saying GE because you have a GE breaker there and so I'm guessing you have a GE panel.. if you don't well - lookup the docs for your panel ). That will also tell you about how the breaker needs to be placed (generally it needs to straddle two regular slots so it basically takes 1/2 of each regular slot - note that it is NOT just connecting to the same connection point as a regular breaker does, modern tandem breakers have different connectors to restrict use to only the allowed slots).

The main downside is that you're cramming more power density into a smaller panel so you can have heat issues (which cause nuisance trips). I tried to move all of the high amp common usage things (like the computer room) up into the non-dual break section of the panel and put the intermittent use things down into the dual breaker section.

I would wonder somewhat about the experience level of an electrician who'd never heard of these. They aren't super super common but are not exactly rare either. I know some electricians don't like them because of the potential for panel overload (to many amps - but some thought makes this an effective non issue) or the possible heat/nuisance trip issue.

[Mike Cutler]

Look closely at that photo. This is really two doubled 120 breakers, i.e. 4 120 poles, with the middle two tied together. It is 2" wide and straddles two normal slots in the panel, so in most panels it will see the opposite pole on each half, giving you 220V. However, unless you are desperate for branches in the panel, why would you use this instead of an ordinary 2" 220 breaker? And if you are that desperate for slots, your inspector will probably tell you the panel is overloaded and needs to be replaced!

Steve
To digress slightly, that configuration, with a 30amp/220 instead of a 20 amp/220, we used to call an "appliance breaker", and it's a pretty expensive item.
If you were renovating and needed to add laundry service, that one breaker met all of the needs. Dryer, washer, and convenience receptacle.It would preclude overloading the neutral return. The models for the high capacity electric ovens and ranges are similar, very expensive also.

Randy
The breakers you are referring to are called "Split", "Mini", and per most electricians, the code, and the literature for a panel, a "Tandem" breaker. There are specific code requirements for their use, installation, and their specific physical location inside the panel is part of the manufacturers design. Panel Manufacturer's will specify which slots, if any, can be used for a tandem application. Some manufacturer's do not allow any use of tandems in their panels, and thus do not make them under their own name.
The box you mentioned has 20 slots and while tandems will save you room, it doesn't mean it will be correct, or code compliant. The box, by design, is only supposed to have a certain number of current carrying conductors. it would be a shame if you got it all loaded up and the building inspector gave you the big thumbs down.
A sub panel in the same building space is a very easy install, and you may find that it will be more cost effective in the end than populating your current panel with tandems. It will also facilitate future expansion.

[Michael Mahan]

Steve
To digress slightly, that configuration, with a 30amp/220 instead of a 20 amp/220, we used to call an "appliance breaker", and it's a pretty expensive item.
If you were renovating and needed to add laundry service, that one breaker met all of the needs. Dryer, washer, and convenience receptacle.It would preclude overloading the neutral return. The models for the high capacity electric ovens and ranges are similar, very expensive also.

Randy
The breakers you are referring to are called "Split", "Mini", and per most electricians, the code, and the literature for a panel, a "Tandem" breaker. There are specific code requirements for their use, installation, and their specific physical location inside the panel is part of the manufacturers design. Panel Manufacturer's will specify which slots, if any, can be used for a tandem application. Some manufacturer's do not allow any use of tandems in their panels, and thus do not make them under their own name.
The box you mentioned has 20 slots and while tandems will save you room, it doesn't mean it will be correct, or code compliant. The box, by design, is only supposed to have a certain number of current carrying conductors. it would be a shame if you got it all loaded up and the building inspector gave you the big thumbs down.
A sub panel in the same building space is a very easy install, and you may find that it will be more cost effective in the end than populating your current panel with tandems. It will also facilitate future expansion.

+1
my point exactly but better explained
that is what I did & the sub panel is right next to the main so there was no extensive re-wiring to be done

[Rich Riddle]

The reason you utilize the single receptacle with two horizontal slots is so that one does not accidentally place a 120 VAC item into a 240 VAC outlet. If you look closely at the 20 Amp double receptacle you will notice that any 120 VAC appliance can also install directly into it. That would not be good.

Look on your sub-panel and you will notice that there are "bars" to which a breaker snaps in place. On a 1" wide double breaker you will see that there is only one "bar" in which your breaker snaps. That shows you that you are drawing all the power from one "hot" side of your service. You must have a breaker that can snap over two "bars" in order to draw current from both 120 VAC "hot" sides of your service. Hope that makes sense.

[Rich Riddle]

It occurred to me today that they do make the type of outlet you're wanting in a duplex receptacle. I have them in the garage, but they had to be ordered online. Here is a picture of the outlet. Actually, the garage has two types of 220 VAC 20 amp plugs. It's obviously the one on the right in the picture.

DSCN1185.jpg

[Earl McLain]

I installed duplex 20a recepts also. Could have bought them locally, but at about 4 times the price. It's a Leviton outlet. Sprayed the cover with the closest thing to red we had in the house. Kind of a cool color when it dried!!

[Phillip Gregory]

Attachment 283629Attachment 283630

I have pulled wire for a 20 amp 220 circuit in the new shop. I am wondering if it is acceptable to use the 20 amp double plugs on a 220 circuit versus the single plug heavy duty receptacle (see photos)? Also, is there any reason I can't use a 220 breaker for this circuit that is 1" wide vs. 2" normal(the inspector has never heard of them)?

Thanks

You can run multiple receptacles on a 240 V branch that does not exceed 20 amps in total current capacity per the NEC, so a duplex 20 A/240 V receptacle is perfectly fine. Rich Riddle above even shows a picture of such a receptacle. Just be careful that most 240 V equipment generally draws at least 8 amps (else it would be wired 120 V) so don't accidentally overload your branch circuit by plugging multiple 240 V tools into it.. I'd probably only put one duplex receptacle per branch unless you have a good reason to do otherwise (limited number of machines running simultaneously and limited service panel space for 240 V circuits.) A subpanel is a pretty good idea that I would do if I were in a cramped main service panel situation.

Do note that anything over 20 A branch circuit capacity requires a dedicated single receptacle. Essentially that means anything 5 hp and better requires its own dedicated receptacle and branch circuit.

[Julie Moriarty]

Randy
The breakers you are referring to are called "Split", "Mini", and per most electricians, the code, and the literature for a panel, a "Tandem" breaker. There are specific code requirements for their use, installation, and their specific physical location inside the panel is part of the manufacturers design. Panel Manufacturer's will specify which slots, if any, can be used for a tandem application. Some manufacturer's do not allow any use of tandems in their panels, and thus do not make them under their own name.
The box you mentioned has 20 slots and while tandems will save you room, it doesn't mean it will be correct, or code compliant. The box, by design, is only supposed to have a certain number of current carrying conductors. it would be a shame if you got it all loaded up and the building inspector gave you the big thumbs down.
A sub panel in the same building space is a very easy install, and you may find that it will be more cost effective in the end than populating your current panel with tandems. It will also facilitate future expansion.

+1

If I may add, some local codes do not allow for split breakers, so Randy, if code compliance is an issue, call your inspector. Most local codes in and around Chicago do not allow them. The reason is they allow for the panel to be overloaded. Also, installing a breaker handle tie is also against many codes. The one in the picture that has two split breakers in it, would be against every local code around here.

On adding sub panels - Ultimately, the rated load of your service should be considered when adding a sub panel. You cannot add sub panels indefinitely. The service conductors your utility company brings to your house has a rated load, overhead having a higher rating than underground, for the same conductor size and insulation. I've upgraded many 100A panels to 200A that required the service drop be replaced. Homeowners thought they were getting more power and more breaker spaces until I had to break it to them the wires coming to the house wouldn't handle the new panel they wanted. If you have an amp probe, you can find out what the total load on your service is.

Randy, so you understand what's going on with your needs, your 240v (usually referred to as 220v) panel is fed from a transformer off a single pole of a three phase system. A transformer takes that, knocks down the voltage and splits it into (2) 120v legs. The three wires coming into your panel are two hots and one neutral. The hots terminate at the two lugs which in turn feed the metal tabs you see for the breakers (the metal is called busbar). To get 240v, a breaker needs to connect to two bus bars, that's why it looks like two breakers. The split breaker only attaches to one busbar so you'll never get 240v off the two terminals on that breaker. Run two wires out of that breaker and connect them to a receptacle and whatever 240v load you plug in won't work. If you take a voltage tester to the two sides of the receptacle, you won't get any voltage reading. The power is there, it just has nothing to complete the loop because both wires are the same.

If you need 240v, you have to connect to both busbars on your panel. And then you have to pull the correct size wires for the anticipated load.

[Joseph Tarantino]

Thanks for all the replies on the receptacles, I thought that was the case but several people have told me there are 20amp 220 receptacles that have two sets of screws (I haven't been able to find them). I will use the single receptacle and just pigtail them together.

here is a 20A 240V duplex receptacle that is legit:

http://www.amazon.com/Leviton-5822-I...olt+receptacle

and here's is a duplex tha's both 110 and 220:

http://www.amazon.com/Leviton-5842-I...olt+receptacle

20A 220 on top, 20A 110 on the bottom.

[Scott Driemel]

Randy. Not certain if the code if different for USA vs Canada but I just put 4 x 30 amp, 1x50amp, and 6x20amp plugs into my new woodshop. I asked the inspector if (as I'm a one man hobby shop only) if I could run multiple receptacles off a circuit. Especially for my welders (each takes a 50 amp receptacle) I told him I'd like to leave them all plugged in so I don't have to fight with the plugs each time. He said "what if you have someone over & you both start welding on a different machine while both plugged in?" I said, well it'd blow the breaker of course but it will never occur. Same as where I have 2 cabinet saws,, planer, bandsaw, jointer, -all 20amp receptacles. I got the speech that EACH tool I wanted to leave plugged in HAD to have it's own 20 amp or whatever amp receptacle was recommended for it installed. Call me lazy, but I didn't want to be stooping down, unplugging tools each time I went to use a different one. I checked with our City Hall, checked with a couple of electricians and yup, that's what I had to do. Cost me over $500 extra. But I drew the line as running 6G wire & a 50 amp breaker 4x 40 feet would have broke the bank. I had no way around it. All receptacles had to be non duplex only if on 240V.
I had my machines in the shop, (a mistake) and he actually walked around looking for the amp ratings on them to ensure I had the correct wire size & breaker. (I suppose that is his job though right?)

[Julie Moriarty]

Codes vary from one municipality to the next. And even within a given municipality, different inspectors may have their own interpretation of the code. The only way to know for sure if something will pass code is to call the inspector and ask. Better yet, have him or her come out and discuss it. The first thing I do when starting a new job is ask the inspector to come out so we can walk it and I can find out what his or her idiosyncrasies are. Saves a lot of headache and expense in the long run.

[Randy Gazda]

Codes vary from one municipality to the next. And even within a given municipality, different inspectors may have their own interpretation of the code. The only way to know for sure if something will pass code is to call the inspector and ask. Better yet, have him or her come out and discuss it. The first thing I do when starting a new job is ask the inspector to come out so we can walk it and I can find out what his or her idiosyncrasies are. Saves a lot of headache and expense in the long run.

Great advise. I have been in regular contact with my local inspector since beginning this project. I was mostly trying to maximize space for future use in the panel. In the end I installed standard 220 breakers and thin 110 breakers (the inspector was fine with this). I still have a few spaces left for future use and have no need right now for a sub-panel. I may want a 60 amp breaker in the future for a welder but for now, I am set. I sheetrocked the garage and shop installed OSB around the panel for future access.

Thanks everyone for the advice.