Using 50 amp RV receptacle for welder

[Raisedonadeere]

I have just run the 50 amp RV receptacle and am mindful that I want to upgrade my Hobart 120V mig welder to a more powerful model requiring 240V. But as I was considering what to run for the future welder I realized that the RV receptacle is located at the same location I would want a welder outlet.

Considering the RV receptacle is used very little, only for occasional visitors and that also the welder use would be infrequent, I mused that I should just wire a RV plug onto my welder but not connecting the neutral, perhaps remove the neutral prong as well.

What would be stupid, dangerous, wrong with this approach. It seems to me, future owners of this home would only be left with a viable 50 amp RV receptacle and where ever the welder winds up it would be perfectly safe plugging into any 50 amp RV receptacle.

 

[yatg]

An RV has a 14-50 plug, a welder has a 6-50 plug.
A 6-50P won't fit in a 14-50R receptacle.

Wire the RV plug properly and use or make an adapter, 14-50P to 6-50R
https://www.amazon.com/gp/product/B07M5CBXJW/?tag=atomicindus08-20

 

[sberry]

Yes, an adapter, it's a legal setup. 50A on a 50A.

 

[Raisedonadeere]

Yes, an adapter, it's a legal setup. 50A on a 50A.

Thanks, it sure makes sense, just surprised I hadn't come across it. Maybe there are not many who have the 50 amp RV outlets available. Anyway, does anyone know of a source for such an adapter?

Holy cow!! googled it and found a number of sources, Home Depot for one. Price $64. Think I will cut off the end of my future welder cord and wire in the 50 amp RV plug I have and cut off the neutral prong.

 

[wyliesdiesels]

Thanks, it sure makes sense, just surprised I hadn't come across it. Maybe there are not many who have the 50 amp RV outlets available. Anyway, does anyone know of a source for such an adapter?

Holy cow!! googled it and found a number of sources, Home Depot for one. Price $64. Think I will cut off the end of my future welder cord and wire in the 50 amp RV plug I have and cut off the neutral prong.

Then when you need to use it on a 6-50 outlet you gonna waste time switching back to a 6-50 plug?

And why bother cutting off the neutral prong? it wont do any harm leaving it

youre creating more work than the adapter costs.

 

[sparky 1971]

Thanks, it sure makes sense, just surprised I hadn't come across it. Maybe there are not many who have the 50 amp RV outlets available. Anyway, does anyone know of a source for such an adapter?

Holy cow!! googled it and found a number of sources, Home Depot for one. Price $64. Think I will cut off the end of my future welder cord and wire in the 50 amp RV plug I have and cut off the neutral prong.

The link in post #2 has the adapter cord for $27.40. The 14-50p cord end will probably cost you in the neighborhood of $15.00. Spend the extra $12 for the adapter and leave the welder cord alone.

Edit: I actually just looked at my pricing. The cheap Pass and Seymour 3867 cord end is $15 at my cost. The better ends go all the way up to $75 for the 5745AN.

 

[sberry]

Don't mod the welder.

 

[mike93lx]

If it could be helpful to have other receptacles there, like a 120v for a grinder, light, vac, etc, you could put a small subpanel in. Then separate receptacles for the rv, welder and 120V

 

[dcg9381]

I use the 14-50R exclusively in my work shop for RV/welder. We set these up on 30A or 50A breakers (depending on underlying wiring). The outlets that I have on 30A breakers, I put a 30A label for no other reason than to remind myself... The reality is that a 50A RV doesn't really pull 50A - at least not the ones with 2 AC systems and I've never had one trip a 30A 2-pole breaker..

The only electrical "no no" here is if I'm running my 30A welder with a 30A cord into a 50A socket on a 50A breaker... That is, using a welder in a true RV outlet. Technically, a short at the welder could smoke the cord on the welder.

My portable generator (setup for a 50A RV) also doubles to create a portable welder.


If you're looking for a good "all in one" deal for - check out a Siemens Talon sub panel. For about $160 bucks, you get 50A, 30A, 20A GFCI breakers and outlets all on one sub-panel with 4 slots for additional breakers.

 

[sberry]

Welders that come with a 50 end are designed to plug in to 50.

The only electrical "no no" here is if I'm running my 30A welder with a 30A cord into a 50A socket on a 50A breaker... That is, using a welder in a true RV outlet. Technically, a short at the welder could smoke the cord on the welder.

 

[dcg9381]

Welders that come with a 50 end are designed to plug in to 50.

Welders I buy don't come with cord or socket.. :-(

 

[dave*99]

The only electrical "no no" here is if I'm running my 30A welder with a 30A cord into a 50A socket on a 50A breaker... That is, using a welder in a true RV outlet. Technically, a short at the welder could smoke the cord on the welder.

That’s not a no no. The breaker is there to protect the wire between the receptacle and breaker. Not to protect the line cord.

It there is a short in a string of Christmas lights the string cord can smoke but the wires to the receptacle will be fine.

 

[sberry]

Actually,, the breaker really doesn't protect the wire in that fashion on a welder circuit. It does on general circuits with multiple recepts but on equipment like welders it is by load calc or applied load,,, remember,, a welder wire can be smaller than breaker.
As to welders without cords or plugs,, this is why the warning about qualified electricians doing the hook up,, doesn't really need a licence but needs to be familiar with equipment of this nature. There may be imports different,,,, not sure about them but have never seen one that is 240V that isn't 50 rated. New MVP have a special adapter that allows it, the 240v models have a 12 cord rated for short circuit on 50A circuits.

 

[sberry]

Christmas lights add extra protection for smaller wires, old ones with old lamps had heavier wire, both for load and for short circuit. General circuits can have lots of outlets and connected equipment, , needs thermal protection to prevent overloads.
BTW,,, this just a ramble, not pointed at any person.

 

[Raisedonadeere]

Actually,, the breaker really doesn't protect the wire in that fashion on a welder circuit. It does on general circuits with multiple recepts but on equipment like welders it is by load calc or applied load,,, remember,, a welder wire can be smaller than breaker.
As to welders without cords or plugs,, this is why the warning about qualified electricians doing the hook up,, doesn't really need a licence but needs to be familiar with equipment of this nature. There may be imports different,,,, not sure about them but have never seen one that is 240V that isn't 50 rated. New MVP have a special adapter that allows it, the 240v models have a 12 cord rated for short circuit on 50A circuits.

Thanks for that information, -- I hadn't researched larger welders power requirements yet. I was just wanting to be sure I didn't need to run a separate welder circuit taking advantage no dry wall just yet.

 

[sberry]

Obviously no need for another wire if both are not used at the same time. Its kind of a habit for me to run a home circuit for each machine. I have 2 other spots in the shop, one on the other side has 1 welding outlet and one on my hoist,,,, 6 at their home, each machine has 1. But,,, I am a daily driver so to speak and want a flip of the switch start up. Its not needed but have a smaller breaker on a couple,,, I had a handful of 30's so I use them for smaller machines. Some 10 wire 30, some 10/50, a 6/50 as I had the wire, would have used 8 or 10 if I had to buy it.

 

[sberry]

Small 240V feeders allow 14 wire/30 breakers but,,, no one likes that. I have wired a couple for others lately 12/30 and even one with 2 recepts this way but both wires land on the breaker, not a daisy chain.
They are allowed on 50 circuits provided the wire is 12 or better,,, but they don't need it. The Hobart 187 or 190 I think is single voltage and comes with a bigger cord than the 210 MVP. Has a 12 cord to allow it on 50A. Uses the same one as the Stickmates have for decades.

 

[dcg9381]

That’s not a no no. The breaker is there to protect the wire between the receptacle and breaker. Not to protect the line cord.

Dave, you misunderstood. My breakers are installed with the correct amps between the outlet and the panel to protect that wire. IE - I have 50A outlet, 30A feed wire, on a 30A breaker.... This still "works" for RVs, because till you're using a 4-AC Willie Nelson tour bus, most operate on under 30A of 240V.


The "no no" case is where I have a 30A extension cord for my welder that is potentially plugged into a 50A RV outlet.

 

[sberry]

The 30 cord is legal on a 50 outlet for welders. Welders with 12 cord legal on it. The 30 feed and breaker to a welder recept is legal install,,, its not really to a 14/50 but its not really a danger.

 

[sberry]

This is just ramble so check with specifics before quoting me,,, I got to put this disclaimer in here so I don't put my **** in the wringer but.....
50RV to 30rv is a legal adapter, a 50 to 30 240 could be legal, have to think about that,,, and 50 to 20 is not legal. You can plug some (stick to welders for the moment so as not to confuse me) things with 12 cord in to 50A and have to think about it, but a 12 or 10 works but as a legal matter might have to be 8,,, not the same as putting an end on a machine.
Other than welders anything with a recept needs the wire and breaker both to support it, so 30 means 30, but also to limit short circuit within a lot of equipment. A buzz box has no thermal, bunch of 12 wire on a 12 cord, depends on the breaker for this. As long as the wire in the wall circuit is as good or better than the cord it wont overheat it.

 

[sberry]

A 4 inch grinder, 6 or 7 A, comes 16 cord and 15 end, on a dedicated 15A circuit its simply an off/on/short circuit interupter. On common 120 gci it provides fault to the wire before the device, both neutral (grounded conductor really) and egc. and after it the line to neutral and the gfci interrupts a ground fault. Gfci is so good as it makes up for any error along the way, even an open ground before it...…………...

 

[dave*99]

Dave, you misunderstood. My breakers are installed with the correct amps between the outlet and the panel to protect that wire. IE - I have 50A outlet, 30A feed wire, on a 30A breaker.... This still "works" for RVs, because till you're using a 4-AC Willie Nelson tour bus, most operate on under 30A of 240V.


The "no no" case is where I have a 30A extension cord for my welder that is potentially plugged into a 50A RV outlet.

I understand completely. And your wiring is legit. And plugging in an extension cord of smaller ampacity than the circuit is legit.

Your 30A cord is ok plugged into a 50A circuit. The extension cord is sized to the welder load. Look at it this way. We can have a 20A wall outlet with a desk lamp that has a 18ga lamp cord plugged in. The lamp cord is sized to the lamp load. Legit.

The reason the discussion is going round and round is that you COULD have a dedicated WELDER outlet where with proper design, the wire feeding the outlet could be a smaller gauge than normally used with a given breaker.

But you don’t have that. You have full capacity circuits set up for RV’s. and you are not committing any no no’s

 

[sberry]

Yes, good splainin.

 

[dcg9381]

We can have a 20A wall outlet with a desk lamp that has a 18ga lamp cord plugged in. The lamp cord is sized to the lamp load. Legit.

Good example..makes total sense.

The reason the discussion is going round and round is that you COULD have a dedicated WELDER outlet where with proper design, the wire feeding the outlet could be a smaller gauge than normally used with a given breaker.

Got it!

For me, a "dedicated welder" outlet isn't as flexible. I've literally got 6 RV outlets, so using that connector type allows me to drag the welder to lots of different locations.. and have the whole setup be portable via use of the same generators that I use for the RV. Now if I could only stop building gates that I can't lift.....

 

[dave*99]

Good example..makes total sense.



Got it!

For me, a "dedicated welder" outlet isn't as flexible. I've literally got 6 RV outlets, so using that connector type allows me to drag the welder to lots of different locations.. and have the whole setup be portable via use of the same generators that I use for the RV. Now if I could only stop building gates that I can't lift.....

There are two approaches to welder discussions - and sberry it the absolute expert on wiring a welder. But be mindful of the question you ask. Example:

I have a model XYZ welder that runs on 240 and the manual says use a 50A breaker. What size wire do I need for a dedicated outlet for only that welder?

You might get an answer like "You can use 10 gauge" The duty cycle of that welder is such that the welder will overheat before the 10 gauge wire does.

I think I want to buy a welder and I might start with a smaller one and then get a bigger one and was offered a used one and I want to put a wire in the wall before I sheetrock, what do I do?

You probably get: "run 6ga on a 50A breaker and you will be able to connect many different models to that. And if you pull a neutral too, you could connect an RV.

I have a 30A dryer outlet fed with 10ga. Can I connect a welder?

The point: An RV outlet is likely useful for both an RV and a welder.

A dedicated welder outlet is sometimes not useful for an RV.

The answer depends upon the question - or at least it should.

 

[dcg9381]

Summary:
50A 240V welder outlet - works welder, will not work RVs
50A 240V RV outlet with neutral - works welder, works for all RVs
30A 120V RV outlet - works single AC RVs, does not work with most welders
30A 240V RV outlet (this is a 30A circuit with a 50A RV connector) - works for all RVs (except tour buses) , works medium duty welders

 

[sberry]

30A 240V RV outlet (this is a 30A circuit with a 50A RV connector) - works for all RVs (except tour buses) , works medium duty welders

Yes, this is safe. But I think the 50A in that case may call for a 6,,,, like there is not an exception for a range which is what the rv plug really is for wiring it any other way. I agree you are not going to overload it fussing around, lots of people use a 120/20A and survive it.
The summary is pretty correct.

 

[sberry]

One of the reasons for the adaption is a guy might not have all the breaker space and it does utilize the same wire. Great for occasional use from long runs. I got a 300 tig, only use it from 1 place, got some cord for another machine to allow it to move and some leads on another and really don't need to weld flat out everywhere. Ideally is to have the machines at a home so to speak and a bench/work area, machine plugged in to a recept designed for it.