"Stringing Together" 220v Recept's

[Spudland_Dave]

So why is it, in the world of 120v, all recepticles are designed to be strung together, 1 circuit, sky is the limit on outlets. But in 220v stuff, its basically "Point to Point" wiring only?

I'm just thinkin...why or how is it any different...(besides the fact the actual devices dont allow for multi conductors)... why couldnt I string together 2 NEMA 6-50's? That way I could leave the Welder & Plasma plugged in?

Are there any 220v outlets that allow for contuining the run?

 

[madosta]

I'd like to know as well.

I think some of it has to do with cost and the amount of current these things draw. If you think about splicing #6 together, you'd need at least two 3-way polaris taps or similar and a junction box, etc.

Pulling a straight shot would be easier though it would use more material, plus the circuit will be dedicated to a breaker, even though electrically it isn't much different than a 120v circuit or sub panel.

 

[ishiboo]

So why is it, in the world of 120v, all recepticles are designed to be strung together, 1 circuit, sky is the limit on outlets. But in 220v stuff, its basically "Point to Point" wiring only?

I'm just thinkin...why or how is it any different...(besides the fact the actual devices dont allow for multi conductors)... why couldnt I string together 2 NEMA 6-50's? That way I could leave the Welder & Plasma plugged in?

Are there any 220v outlets that allow for contuining the run?

Because 120 receptacles are so common and are almost always wired together, and 240 receptacles are typically single use - like a dryer, stove, etc. Why have that added cost to a device which rarely sees that use?

Just use wire nuts and pigtails to connect the 240 devices... that's the proper method anyway.

 

[Spudland_Dave]

I'm just thinking I'm a one man band...at most my Son will tinker when older...but safe to say we wont have 15 welders on at any time...so by having 2 6-50R's a foot apart, the Plasma stays plugged in and the welder stays plugged in. We all know its a PITA to be plugging/unplugging when working...

As for Added costs....I would think it would be cheaper in a garage setting...sure I know what you mean for a Stove & Dryer...but they arent exactly giving away 6-2 Wire these days either... So for me to only need 1 run of wire, vs 2 runs makes it alot cheaper.

Even then...alot of welders dont even draw the full 50A load...even though 6-50P is the industry standard plug...my little Maxstar 150 came with a 6-50P on it and the actual cord itself is only a 10ga...that tells me Miller knows it draws less then 30A... heck it came with a NEMA 5-15 as well (it has the Fancy Miller MVP setup)...

.......I know things are what they are...was just wondering this philisophical question...LOL

 

[ForceFed70]

When I wired my garage, I put in 6 x 240V welder plugs all around the garage so I would always have a plug handy instead of having to use a 240V extension cord. They are all on the same circuit AKA "Strung Together".

But Ishiboo hit the nail on the head. 240V loads are usually well planned as to their location and rarely need extra plugs strewn about. I wired 5x 240V circuits in my garage but the welder circuit is the only circuit I felt the need to have multiple outlets.

 

[madosta]

How does one wire-nut 3 6awg wires together though?

Without using polaris taps or split-bolt like devices?

 

[Steevo]

I ran a few 240v "convenience" receptacles in my shop when I wired it.
I used 10ga Romex, and ran it to the first receptacle on a wall, pigtailed with wire nuts, then ran along to second receptacle.
2 receptacles on each of three walls, one breaker per wall, two receptacles per 30A two-pole breaker.
These are so I can use a 240v wire welder anywhere without an extension cord, or as in the case of the one wall, I ended up putting my milling machine near one of the receptacles as it is 240v. I may plug a drill press or other machine into the second one on that wall, but I can't very well run them both at once anyway.

There are four other, higher-amperage, dedicated 240v receptacles for things like the compressor, main welding bench, water heater, etc. These are all home-runs to the panel.

 

[Zeke]

Dave, theory (or "this philisophical question") and code will differ. The answer to your question is that YOU can do it. As a contractor, I doubt if I would do that for you.

Most 120v plug circuits have 15A receptacles installed in the boxes. Rare that someone would have a 20A NEMA 5-20 cord that they wanted to use. If so, they should consult an electrician or, at the very least, determine if there is 12ga. wiring on a 20A breaker and change out the receptacle to a 20A.

How would you as a landlord address the issue of those multiple 220 outlets? That's where the rubber meets the road.

 

[madosta]

I mean if a 6-50R is rated for 50amps, and wired on a 50amp breaker and #6, adding 100 outlets would be no different.

Wonder what the issues are. Where are those sparkies at?

 

[Spudland_Dave]

I ran a few 240v "convenience" receptacles in my shop when I wired it.
I used 10ga Romex, and ran it to the first receptacle on a wall, pigtailed with wire nuts, then ran along to second receptacle.
2 receptacles on each of three walls, one breaker per wall, two receptacles per 30A two-pole breaker.
These are so I can use a 240v wire welder anywhere without an extension cord, or as in the case of the one wall, I ended up putting my milling machine near one of the receptacles as it is 240v. I may plug a drill press or other machine into the second one on that wall, but I can't very well run them both at once anyway.

There are four other, higher-amperage, dedicated 240v receptacles for things like the compressor, main welding bench, water heater, etc. These are all home-runs to the panel.

Steevo...what you describe is EXACTLY what I'd like to do and what I had in mind when I pondered this prior to falling asleep...LOL

I mean if a 6-50R is rated for 50amps, and wired on a 50amp breaker and #6, adding 100 outlets would be no different.

Wonder what the issues are. Where are those sparkies at?

Bingo... Why does 220v/higher amp stuff make it any different? Whether you overload a 20A 110v circuit or overload a 50A 220v circuit...if its wired with correctly sized wires, protected with the correct breaker...To me the only issue is having wiring devices like Recepticles which are "Double Lugged" to allow for other recpticles.

I suppose back in the "olden days" when copper was cheap it wasnt a big deal...but at 2.00/ft 6-2 and 6-3 runs add up FAST. Even 10-2 isnt cheap anymore. Imagine the costs if you had to wire each 110v recepticle point to point...even if you used 14-2...I can clearly see why it was reccomended to me to install a 2nd panel in my garage...just the cost savings on a single 50A circuit pays for the entire panel and enough breakers to fill the entire 20 space panel.

 

[offroadsteve]

Short answer is that it's a code requirement, at least in Virginia.

Section E3702.5 of the VA residental code, 2009 source specifies that general purpose branch circuits serving multiple outlets or lighting fixtures shall be limited to 20 amps. No voltage is specified, so one assumes that 240V/20A multi-outlet circuits are acceptable.

My theory on the "why" is that anything that needs more than 20 amps is typically a dedicated piece of equipment that isn't going to move around, which in general is a pretty good assumption.

All that being said, I personally would have no problem doing what ForceFed70 described in his garage for a one-man show. I have also built a multi-outlet extension cord to be able to have 2 welders hooked up to a single outlet before, since we had no control over the building wiring.

 

[ForceFed70]

Interesting. My welder outlets were on a 30A circuit and the inspector didn't bat an eye. I used wire nuts rated for the purpose (3 x 10ga copper conductors). Having said that, I wouldn't attempt this on a 50A circuit. 10ga was difficult to make a good connection with - 8ga or 6ga would be nearly impossible with a standard wire nut.

I'm in Canada and code is a little different but from what I've seen 98% of Canadian code is based on the NEC. Inspector told me to follow NEC 2006 (this was 2 years ago).

 

[rlitman]

Having said that, I wouldn't attempt this on a 50A circuit. 10ga was difficult to make a good connection with - 8ga or 6ga would be nearly impossible with a standard wire nut.

Deciding on what combination of wires can be used with a wire nut is simple. It is ALWAYS spelled out on the box.
A 3M B/G wire nut is rated for (2) #6 wires, or (3) #8, so yes, you could put together three #8 wires with that.
If you wanted to put together (3) #6 wires, you are looking at Polaris connectors (the good way), or split bolts.

 

[theoldwizard1]

Trying to think logically ...

Most 120v loads/"appliances" do not come anywhere close to the "typical" circuit limit (15A). Therefore turning on several loads at the same time, on the same circuit, will still not overload it.

Most 240v loads/"appliances" are usually close to the circuit limit (do you install 8 gauge wire and a 50A breaker to run a 20-30A compressor motor ?) Therefore turning on an additional load will trip the breaker. Kind of defeats the idea of having a second receptacle except to have it in a different part of the area.

 

[frankush]

Short answer is that it's a code requirement, at least in Virginia.

Section E3702.5 of the VA residental code, 2009 source specifies that general purpose branch circuits serving multiple outlets or lighting fixtures shall be limited to 20 amps. No voltage is specified, so one assumes that 240V/20A multi-outlet circuits are acceptable.

My theory on the "why" is that anything that needs more than 20 amps is typically a dedicated piece of equipment that isn't going to move around, which in general is a pretty good assumption.

All that being said, I personally would have no problem doing what ForceFed70 described in his garage for a one-man show. I have also built a multi-outlet extension cord to be able to have 2 welders hooked up to a single outlet before, since we had no control over the building wiring.

The key here is whether or not these 30 or 50A outlets would be considered general purpose. The answer is usually no. Asking your inspector about multiple 220V receptacles on the same circuit is a good idea. You just have to understand that if you try to use both pieces of equipment at the same time, you will trip breakers.

 

[sberry]

Depends on rhe machines connected to it. A Maxstar and a 375 plasma could be connected to 50A as long as each one was fed with a 12 or better wire.

 

[Spudland_Dave]

Trying to think logically ...
Most 240v loads/"appliances" are usually close to the circuit limit (do you install 8 gauge wire and a 50A breaker to run a 20-30A compressor motor ?) Therefore turning on an additional load will trip the breaker. Kind of defeats the idea of having a second receptacle except to have it in a different part of the area.

You got a point there...but certian items, like welders for example dont come close to the 50A load either...my Maxstar for example. AND its a variable load...when welding at low amps, it will draw less current.. How often are you welding at 100% Duty Cycle 2" Thick steel at 205A on your welders?
Add to that, I'm one guy...cant be welding with 2 welders at the same time... How many "portable" tools require full load? If I were designing a production kitchen I wouldnt wire up 3 Ranges like this..LOL

Depends on rhe machines connected to it. A Maxstar and a 375 plasma could be connected to 50A as long as each one was fed with a 12 or better wire.

If I were to put a 50A Recep's on it, I'd use 6ga wire everywhere...so I'd have a true 50A available to me safely. Like mentioned originally, I'd treat it just like a normal 20A group of outlets.

 

[housey]

Its the same over here, due to the fact that the majority of general household appliances will only draw a fraction of the circuits limit and it would be costly/unnecessary to have each one on its own dedicated circuit.

Then there is also the possible issue of volt drop or getting a hot connection, do you really want 50 amps flowing through half a dozen joints made with bluepoints(I believe bluepoints are similar to the wirenuts you guys use in the US), or pigtails?

 

[hidollartoys]

You should consider using the feeder tap rule. It will save on wire size at the use location.

 

[Spudland_Dave]

Then there is also the possible issue of volt drop or getting a hot connection, do you really want 50 amps flowing through half a dozen joints made with bluepoints(I believe bluepoints are similar to the wirenuts you guys use in the US), or pigtails?

Absouletly correct..and while this is a great discussion, like I said in my OP..its purely academic at this point. I wouldnt wire nut a chain of 110-20A recepts together...theres a reason theres multiple mounting screws on a recep.. To make this work we'd need multiple lugs on the recept...

You should consider using the feeder tap rule. It will save on wire size at the use location.

Googled it ...I'll need to find an english version that I can understand...

 

[pattenp]

Absouletly correct..and while this is a great discussion, like I said in my OP..its purely academic at this point. I wouldnt wire nut a chain of 110-20A recepts together...theres a reason theres multiple mounting screws on a recep.. To make this work we'd need multiple lugs on the recept...




Googled it ...I'll need to find an english version that I can understand...

Basically you could have the main circuit as you said being #6 on a 50A breaker. But you could use #12 for pig tails to the outlets. In this case the short pig tail pieces are what's referred to as tap conductors.

 

[madosta]

Basically you could have the main circuit as you said being #6 on a 50A breaker. But you could use #12 for pig tails to the outlets. In this case the short pig tail pieces are what's referred to as tap conductors.

This makes my head spin.

 

[pattenp]

This makes my head spin.

There are some restrictions to using smaller wire for taps, so don't just wire up #12 taps off of a 50A circuit just for any kind of use.

 

[Aceman]

I wouldn't use taps in a residential setting.....