Changing Nema 6-15 to Nema 6-50 receptacle

[kentagon]

Hello Welding Web!!

I am excited to be here right now
I just bought a Lincoln 180 MIG welder.
In my garage there is a 250v 15amp Nema 6-15 receptacle.
How do I install the Nema 6-50 receptacle so I can start welding?

[DKMOBILEWELDING]

Hey chief one problem you need more than a15 amp breaker to run that welder it probably requires like 30 to 50 amp breaker if you have a dryer near by you could use that to power it i dont now where you live but they make a plug that fits the dryer outlet and the other end fits the 230 volt end no monkeeing around just plug it in and go you would 'nt be able to run it full tilt but it will get you going for now

[ccawgc]

call an electrician and ask what needs to be done to your shop.
you may want to run a new line from your breaker box and size it all correctly.

[Broccoli1]

Code allows for up sizing the breaker on that size wire used on the 6-15 receptacle due to the duty cycle of the small Lincoln.

14g wire and a 30amp breaker would be OK by code- just make sure you don't put anything bigger on that receptacle.

[tkanzler]

Originally Posted by Broccoli1

14g wire and a 30amp breaker would be OK by code- just make sure you don't put anything bigger on that receptacle.

I agree, but would take it one step further. That welder is rated 20A at 30% duty-cycle, so right off the bat, 14 gauge copper is good to go, as it's rated 20A at both 60ºC and 75ºC.* The ampacity multiplier for 30% duty-cycle is .55, so technically, conductors good to 11A are all that's required, at least as far as that part goes.

The NEC also restricts the overcurrent protection to 200% of the branch circuit conductor ampacity for welding machine branch circuits, so a 40A breaker would be legal on 14 gauge copper conductors, and in fact, that's what the manufacturer calls for (40A, not conductor size specifically).

It also restricts branch circuit overcurrent protection to 200% of the welder's primary current rating, but that doesn't come into play when the conductors are protected as in the previous paragraph, though it works out to the same thing in this case. If larger conductors were used, the 40A max breaker size would still be in effect due to the 20A rating of the welding machine.

Then there's the issue of circuits required to conform to the manufacturer's installation instructions (as long as it doesn't violate any other parts of the NEC), so since the manufacturer specifies a 40A branch circuit, that's what's (technically) required.

I personally don't see any harm in using a 30A breaker, and would probably use one first if I had it laying around. As long as it doesn't trip, good enough is good, but if it did, a 40A is perfectly legal and proper. My welder requires a 60A circuit, but I've never used anything larger than 50A, and never had it trip (even using it for cutting at max output), so there's never been a need to spend money on a larger one.

The OP is probably going to have to pigtail heavier conductors onto those 14 gauge conductors, as a 50A receptacle is not likely rated for conductors smaller than 10 gauge.


*The 15A max overcurrent protection restriction for 14 gauge copper does not apply to arc welder branch circuits, motor branch circuits, hermetic A/C branch circuits, and a few others, as long as the entire NEC section(s) that cover(s) them is observed. Table 310-16 ampacity values can be used as written for these circuits.

[norite]

Originally Posted by ccawgc

call an electrician and ask what needs to be done to your shop.
you may want to run a new line from your breaker box and size it all correctly.

This is excellent advice if you:

1. Don't want to electrocute yourself, family, friends or pets.
2. Don't want to burn your shop and/or your house down
3. Don't want to have your insurance company refuse to cover you in case of 1 or 2 or protect you from a lawsuit.

The reason we need electricians to do this work is not that it is rocket science it isn't, it's just that the consequences for improper wiring are so large. That also means you should be getting a permit and having the work checked by an inspector, whether you do it yourself or have an electrician do it.

I know many here have electrical knowledge, or are even electricians and are eager to help out those who have questions. I appreciate the spirit and good will behind their efforts. I would just suggest that you realize that you are not advising only an O/P who seems to know what he is doing and just needs a little advice but there are many lurking here as guests reading the posts who may have no idea what they are doing and can't even post a question themselves since they have not bothered to join the forum. The other problem is that what is permitted in one area may be improper in another, differing local conditions require local expertise sometimes.

So my main thought is that the first advice we give to posters with electrical questions should be to get an electrician or inspector to advise them and to take out a permit for their own protection.

[jdchmiel]

I you were to use the NEC undersized wire according to limited duty cycle of a welder, IE using 14 guage wire for 40 amps, when it is usually only allowed for 15 amps, I would hard wire the welder to a disconnect box instead of using a plug + outlet. You can use an AC service disconnect type box. This prevents anyone from EVER plugging in something that does not have the duty cycle limitations of the welder into that outlet. Like a bigger welder..