it's quite common that people to think you need 3 wire plus ground for 240 volts

[The Cobbler]

I locally picked up a slightly used 240 heater today along with some cable and a receptacle . I actually have a use for both (individual projects) and it just happened I saw the listing for both at a real fair price .
In the pictures I could see it was 10/3 and I thought, here is another example of someone buying 3 wire when they only needed 2 wire.
what they did was not use the ground. it was cut off short. the white was acting as ground and the red & black were the hots .
another, " you gotta have 3 wires to get 240"

 

[nadogail]

I locally picked up a slightly used 240 heater today along with some cable and a receptacle . I actually have a use for both (individual projects) and it just happened I saw the listing for both at a real fair price .
In the pictures I could see it was 10/3 and I thought, here is another example of someone buying 3 wire when they only needed 2 wire.
what they did was not use the ground. it was cut off short. the white was acting as ground and the red & black were the hots .
another, " you gotta have 3 wires to get 240"

Another example of knowing just enough to be dangerous.

 

[mm08822]

Yup. 120/240V load requirements is not the same 240V load requirements.

 

[Jim greengo]

Depends on the voltage for the blower motor and controls.

 

[Dagny]

nothing wrong with having a wire left over.

 

[PCustoms]

another, " you gotta have 3 wires to get 240"

Well, you do need 3 wires:

Hot
Hot
Ground

 

[mike93lx]

Well, you do need 3 wires:

Hot
Hot
Ground

If we are going to get nit picky, you only need two

 

[logixjock]

220, 221, whatever it takes.

 

[gtae07]

I'll admit, it was confusing to me the first time I bought wire... was putting in another outlet and knew I needed a hot, neutral, and ground... that's three wires, so get 12/3 right?

Most recently I installed a Tesla charger, which doesn't need a neutral. But I couldn't find 4/2 romex anywhere and didn't feel like trying to put conduit in the wall for individual wires, so 4/3 it was. Just capped the neutral.

 

[Lassen Forge]

Here it's load (brown) and neutral (blue), with a separate ground (green/yellow). Everything is 1ø 230 V (house current wise, anyway). Higher voltage is 400 V, 3ø...

 

[Norcal]

3-wire plus ground is fine for 3 phase.

 

[Packard V8]

3-wire plus ground is fine for 3 phase.

Straight three wire is fine for 240-volt systems. The four wire is required when there is a 120-volt tap for lights, motors, control systems.

Had this confirmed recently when we had a ESVE installed for our EV. Most all the internet experts will flatly state a 14-50 four wire plug and receptacle wired into a GFCI breaker is required. That's wrong, wrong, wrong. Our utility gave us the ESVE and sent a contractor to install it. He used flat three-wire and a 6-50 plug into a straight 40 amp breaker. The city inspector said, "That's all you need." The materials were half the cost I'd been budgeting based upon the internet expert bad advice.

jack vines

 

[sparky 1971]

Well, you do need 3 wires:

Hot
Hot
Ground

The ground isn't necessary to make anything work that is 240 volt. Go back in time about 70 or so years and there wasn't a ground wire. The ground is to add an element of safety and 99.99% of the time, there is no current on the ground.

Straight three wire is fine for 240-volt systems. The four wire is required when there is a 120-volt tap for lights, motors, control systems.

Had this confirmed recently when we had a ESVE installed for our EV. Most all the internet experts will flatly state a 14-50 four wire plug and receptacle wired into a GFCI breaker is required. That's wrong, wrong, wrong. Our utility gave us the ESVE and sent a contractor to install it. He used flat three-wire and a 6-50 plug into a straight 40 amp breaker. The city inspector said, "That's all you need." The materials were half the cost I'd been budgeting based upon the internet expert bad advice.

jack vines

The ground isn't counted in the wire count. For instance, 12/2 romex or MC cable is referred to as 12/2 with ground. Three hots and a ground is three phase, 208, 240, or 480. When there is a 120 volt element and three wires, there is a neutral and it's no longer 240 (or 208) it's 120/240 or 120/208.

I have installed a grand total of three receptacles for EV chargers. All three of them were 14-50's. I didn't guess as to what was needed, the customers pulled the cord out of the trunk of the car and showed me what they came with, and every time, it was a 14-50P.

And...most places are going to require those outlets to be GFCI protected, it's in the 2020 code for outside, garages, and within 6' of a sink. Iowa for sure, and maybe others took out the GFCI requirement, but it may get put back in for 2023, time will tell. I have my update class on Nov. 1., the 2023 will probably go into effect on Jan. 1, 2024.

 

[Norcal]

You do not need a neutral for 240V loads, you do need a neutral for 120/240V loads like ranges, ovens, dryers, & 208-230V 1Ø Hoshizaki ice machines , to name a few examples.

 

[gtae07]

Most all the internet experts will flatly state a 14-50 four wire plug and receptacle wired into a GFCI breaker is required.

The "need" for 14-50 is more that most plug-in EVSEs have a 14-50 plug to make use of RV hookups. It's become the unofficial "standard" when the wiring can support it, but it's not an absolute requirement. I can get any number of adapter plugs for my Tesla mobile charger.

The GFCI thing is a recent code addition IIRC. You might not be subject to that revision.

 

[Crazyjake8493]

Nothing wrong with having the extra conductor in there if they already had the cable on hand. Copper isn't cheap.

 

[The Cobbler]

I guess my original thought was that the person bought the cable thinking he needed 2 hots, a neutral and a ground.
maybe even that's what he was told at the place of purchase, who knows.
but what I found odd was the ground was cut off and used the neutral for the ground.

 

[rpcraft]

So this might not be the right thread but maybe someone can help enlighten me on the 3 to 4 prong adapters. I have a few 50 Amp RV cables and doing an extension cord from my garage to my shop/shed, with the idea being, it's not hard wired and when not in use it gets rolled up and stowed. In my county it keeps from increasing my property tax since its technically just a "storage shed" until you add hard wired power.

That said my Garage starting point is a Nema 6-50 plug and only has 3 conductors since it was setup as a welder socket. The 50 Amp Rv cables I have collected off market place have the 4 Prong Nema 14-50 receptacles so I was going to adapt using one of theNEMA 6-50P to NEMA 14-50R adpaters like pictured and extend the RV chords out to a GFCI spider box that also has a 4 prong SS2-50 type socket. My main question is what really happens to the fourth conductor going outwards when you use one of the 3 to 4 prong adapters and will the fact that it is only starting as a 3 prong welder socket at the panel prevent the GFCI in the spider box from working correctly? If it does and I can't run the 120 side of that spider box for the 120 volt in my shop then I can just switch plans to a solar generator or power bank for the 120 stuff. then I would just chop the 4 conductor plug off the cable that ends in my shop and use 3 of the 4 conductors and put a nema 6-50 socket setup on what I need to run off the 240 in my shop.



I'm not trying to be cheap here (well sure a little) but I am just making sure I don't spend 350 bucks on a spider box I just have to end up returning and shifting my plans around.

Thanks for anyone that can help answer the GFCI question.

 

[The Cobbler]

My main question is what really happens to the fourth conductor going outwards when you use one of the 3 to 4 prong adapters

the 4th unused conductor will be the neutral, thus you do not have the ability to have 120v at the garage
only 240 is available with that cord set up, and using and outlet from your welder

 

[CGT80]

Nema 6-50 does not have a neutral. I'm not sure how the adapter works, unless it uses the ground as a neutral, which isn't great.

You would be better off having a 4 pin receptacle to start with. Does the 6-50 receptacle have a neutral run to the box? What color wires feed it from the breaker panel, and how many?

 

[sparky 1971]

So this might not be the right thread but maybe someone can help enlighten me on the 3 to 4 prong adapters. I have a few 50 Amp RV cables and doing an extension cord from my garage to my shop/shed, with the idea being, it's not hard wired and when not in use it gets rolled up and stowed. In my county it keeps from increasing my property tax since its technically just a "storage shed" until you add hard wired power.

That said my Garage starting point is a Nema 6-50 plug and only has 3 conductors since it was setup as a welder socket. The 50 Amp Rv cables I have collected off market place have the 4 Prong Nema 14-50 receptacles so I was going to adapt using one of theNEMA 6-50P to NEMA 14-50R adpaters like pictured and extend the RV chords out to a GFCI spider box that also has a 4 prong SS2-50 type socket. My main question is what really happens to the fourth conductor going outwards when you use one of the 3 to 4 prong adapters and will the fact that it is only starting as a 3 prong welder socket at the panel prevent the GFCI in the spider box from working correctly? If it does and I can't run the 120 side of that spider box for the 120 volt in my shop then I can just switch plans to a solar generator or power bank for the 120 stuff. then I would just chop the 4 conductor plug off the cable that ends in my shop and use 3 of the 4 conductors and put a nema 6-50 socket setup on what I need to run off the 240 in my shop.



I'm not trying to be cheap here (well sure a little) but I am just making sure I don't spend 350 bucks on a spider box I just have to end up returning and shifting my plans around.

Thanks for anyone that can help answer the GFCI question.

That might just be the dumbest idea for an adapter cord I've ever seen. If it's right, you won't have a neutral which means you wouldn't have 120 volt. Hopefully, it's a three conductor cord with a dead neutral at the female end but it's probably from China which means there's a chance that the neutral and ground are connected in the 14-50, which would give you 120 but it ain't right and could be dangerous. Go with plan B. Or C, anything other than A.

 

[CGT80]

A multi meter would quickly tell you what it is....if you had the adapter in hand.

 

[whateg01]

A multi meter would quickly tell you what it is....if you had the adapter in hand.

Betting he's gonna need a diagram

 

[dcg9381]

I have a few 50 Amp RV cables and doing an extension cord from my garage to my shop/shed, with the idea being, it's not hard wired and when not in use it gets rolled up and stowed. In my county it keeps from increasing my property tax since its technically just a "storage shed" until you add hard wired power.

That's not a 30A to 50A "RV" adapter. Look carefully, it's not a 120V plug on the male side of Nema 6-50 plug, which is 240V and no neutral. Best case, it's just a change in plug type, but only 240V capable.

30A to 50A RV adapters are common, they just use one "leg" of the 50A (which is more than enough) and essentially drop a hot leg.

That thing, probably from China, hopefully is hot, hot, ground. 240V. It will NOT work as a "50A RV" adapter because 50A RVs have 120V appliances.

If by chance it terminates the ground and neutral together it may "work" but it's all kinds of wrong. It'd certainly not work with any GFCI type of setup.

Nema 6-50 plug cannot be used for 120V. No neutral. Can you get it to work by bonding the N/G? Maybe, but it's way wrong.

 

[wyliesdiesels]

So this might not be the right thread but maybe someone can help enlighten me on the 3 to 4 prong adapters. I have a few 50 Amp RV cables and doing an extension cord from my garage to my shop/shed, with the idea being, it's not hard wired and when not in use it gets rolled up and stowed. In my county it keeps from increasing my property tax since its technically just a "storage shed" until you add hard wired power.

That said my Garage starting point is a Nema 6-50 plug and only has 3 conductors since it was setup as a welder socket. The 50 Amp Rv cables I have collected off market place have the 4 Prong Nema 14-50 receptacles so I was going to adapt using one of theNEMA 6-50P to NEMA 14-50R adpaters like pictured and extend the RV chords out to a GFCI spider box that also has a 4 prong SS2-50 type socket. My main question is what really happens to the fourth conductor going outwards when you use one of the 3 to 4 prong adapters and will the fact that it is only starting as a 3 prong welder socket at the panel prevent the GFCI in the spider box from working correctly? If it does and I can't run the 120 side of that spider box for the 120 volt in my shop then I can just switch plans to a solar generator or power bank for the 120 stuff. then I would just chop the 4 conductor plug off the cable that ends in my shop and use 3 of the 4 conductors and put a nema 6-50 socket setup on what I need to run off the 240 in my shop.



I'm not trying to be cheap here (well sure a little) but I am just making sure I don't spend 350 bucks on a spider box I just have to end up returning and shifting my plans around.

Thanks for anyone that can help answer the GFCI question.

where is this adapter posted? its a really dumb design since the 6-50 doesnt have a neutral.

as CGT80 stated, i would check the j box where the 6-50r is and see if theres a neutral in there. if there is, switch the 6-50 to a 14-50r and then run your spider box off that.

 

[dscheidt]

That might just be the dumbest idea for an adapter cord I've ever seen. If it's right, you won't have a neutral which means you wouldn't have 120 volt. Hopefully, it's a three conductor cord with a dead neutral at the female end but it's probably from China which means there's a chance that the neutral and ground are connected in the 14-50, which would give you 120 but it ain't right and could be dangerous. Go with plan B. Or C, anything other than A.

The one I looked at had the ground and neutral tied together.

 

[dcg9381]

where is this adapter posted? its really dumb design since the 6-50 doesnt have a neutral.

You can get anything on Amazon, straight off the boat.
"Passed UL certification" lol

https://www.amazon.com/dp/B0BZCTCQGH?tag=atomicindus08-20

 

[wyliesdiesels]

You can get anything on Amazon, straight off the boat.

https://www.amazon.com/dp/B0BZCTCQGH?tag=atomicindus08-20

of course you can. i wanted to know where the OPs item is listed so i can see if they state how they handle the neutral pin

 

[The Cobbler]

 

[wyliesdiesels]

surprised ETL listed that. has to be counterfeit....

 

[sparky 1971]

After reading the description, I doubt anything is connected to the neutral. It says not for dryers (no kidding since there's nothing 14-30 or 10-30 about it) and it also says not for RV's. It's strictly for electric cars and that is why it's frequently returned.

 

[mm08822]

That might just be the dumbest idea for an adapter cord I've ever seen. If it's right, you won't have a neutral which means you wouldn't have 120 volt. Hopefully, it's a three conductor cord with a dead neutral at the female end but it's probably from China which means there's a chance that the neutral and ground are connected in the 14-50, which would give you 120 but it ain't right and could be dangerous. Go with plan B. Or C, anything other than A.

Not having 120v is one thing. If there were 120v loads connected to each hot leg of that 14-50 adapter, they will be put in series and could easily burn up those loads when turned on. No different than an open neutral in a sub-panel, main panel, or at the trans on the pole.

 

[mm08822]

After reading the description, I doubt anything is connected to the neutral. It says not for dryers (no kidding since there's nothing 14-30 or 10-30 about it) and it also says not for RV's. It's strictly for electric cars and that is why it's frequently returned.

I don't know where the ev's came up with needing a 14-50 but it is a waste. 6-50 is all that is needed for them. A hard-wired evs only needs h, h, grd.

 

[sparky 1971]

I don't know where the ev's came up with needing a 14-50 but it is a waste. 6-50 is all that is needed for them. A hard-wired evs only needs h, h, grd.

I don't know it to be true, but I've been told, and it makes sense, that the EV's come with a 14-50 so that they can be plugged into an RV receptacle. I don't know the stats nor do I care but there are probably more RV outlets out there than there are welders. And, if the cord is long enough they could always string it into the kitchen and plug it in behind the range. I've installed three EV outlets, all of them 14-50's, and all of them about five years ago. At that time, I didn't know they didn't need a neutral but I did know it didn't make any sense. The customer pulled a cord out of the trunk with a 14-50P so I installed a 14-50R, collected payment, and moved on.

 

[sparky 1971]

Not having 120v is one thing. If there were 120v loads connected to each hot leg of that 14-50 adapter, they will be put in series and could easily burn up those loads when turned on. No different than an open neutral in a sub-panel, main panel, or at the trans on the pole.

And there's always that as well.

 

[mm08822]

I don't know it to be true, but I've been told, and it makes sense, that the EV's come with a 14-50 so that they can be plugged into an RV receptacle. I don't know the stats nor do I care but there are probably more RV outlets out there than there are welders. And, if the cord is long enough they could always string it into the kitchen and plug it in behind the range. I've installed three EV outlets, all of them 14-50's, and all of them about five years ago. At that time, I didn't know they didn't need a neutral but I did know it didn't make any sense. The customer pulled a cord out of the trunk with a 14-50P so I installed a 14-50R, collected payment, and moved on.

If that is correct then it makes sense. First I've heard that but sounds plausable.

I've only done hard-wired to date. No gfci needed either!

 

[Racer_X]

I wired my CB radio using 10/4.

 

[mm08822]

Roger that

 

[rpcraft]

the 4th unused conductor will be the neutral, thus you do not have the ability to have 120v at the garage
only 240 is available with that cord set up, and using and outlet from your welder

Yeah that is what I was thinking.

 

[rpcraft]

Nema 6-50 does not have a neutral. I'm not sure how the adapter works, unless it uses the ground as a neutral, which isn't great.

You would be better off having a 4 pin receptacle to start with. Does the 6-50 receptacle have a neutral run to the box? What color wires feed it from the breaker panel, and how many?

NO which is why i said my plug in the garage is already a nema6-50 and only has 3 conductors.