Circuit for a Hobart 210MVP

[climb.on]

I'm about to pull the trigger on a Hobart 210MVP. I have several 30amp 240 outlets already installed in my new shop. No 50 amps circuits though - didn't think I needed one. Sure I can run one, and I might...or I might not. But can someone explain why a machine that draws a maximum of 24 amps (which is 80% of 30a) requires a 50 amp circuit? I've read numerous folks who run the machine on 30amp circuits, i'm just curious why the 50a requirement.

Also, they are on sale locally for $799. Am I going to do any better on this machine, if I hold out for a better deal? I'm in no rush.

 

[ItsNemo]

It's a 50a plug that's why but you can absolutely run them on a 30a breaker.

 

[DieselNut88]

I run one on a 30amp breaker no problem.

 

[ishiboo]

I'm about to pull the trigger on a Hobart 210MVP. I have several 30amp 240 outlets already installed in my new shop. No 50 amps circuits though - didn't think I needed one. Sure I can run one, and I might...or I might not. But can someone explain why a machine that draws a maximum of 24 amps (which is 80% of 30a) requires a 50 amp circuit? I've read numerous folks who run the machine on 30amp circuits, i'm just curious why the 50a requirement.

Also, they are on sale locally for $799. Am I going to do any better on this machine, if I hold out for a better deal? I'm in no rush.

Not sure where you see that it requires a 50 amp circuit. The manual states:

Max Recommended Standard Fuse Rating In Amperes: 30A

And requires minimum 14 gauge wiring.

 

[climb.on]

Well it's a 50a plug. Thought I read it too, but not at my computer to check right now.

 

[matt_i]

The NEC allows some derating of a welder circuit (the wire size) due to the "duty cycle" of the machine. In other words the welder itself typically can't run continuously and needs time to cool itself....which also affords time at at zero current to cool the wiring.

There are tables, specs, and regulations I can't quote out of my head. But ask over on th Electrical forum and you will get the answers you need.

One thing to consider, though, is if the 240vac receptacle is going to be 'general purpose' for other things that might come into the shop down the road, it might be wise to wire it for the full 50A (probably #6 awg THHN or so) just in case you figure out how to use that extra capacity.

 

[ishiboo]

Also, keep in mind if you are shopping at Fleet Farm which I think you may be, they offer 10% off the first time you use your Fleet Farm card if you don't already have one. That's another $70.

 

[ishiboo]

The NEC allows some derating of a welder circuit (the wire size) due to the "duty cycle" of the machine. In other words the welder itself typically can't run continuously and needs time to cool itself....which also cools the wiring.

There are tables, specs, and regulations I can't quote out of my head. But ask over on th Electrical forum and you will get the answers you need.

One thing to consider, though, is if the 240vac receptacle is going to be 'general purpose' for other things that might come into the shop down the road, it might be wise to wire it for the full 50A (probably #6 awg THHN or so) just in case you figure out how to use that extra capacity.

No need to quote out of your head... the owners manual has the info he needs. 30A with #14 wire.

 

[ItsNemo]

No need to quote out of your head... the owners manual has the info he needs. 30A with #14 wire.

For the difference in cost though to go to 10awg wire that is rated fully for 30 amps, there's almost no point in under sizing.

 

[climb.on]

I probably saw 50amp plug and assumed that was the required circuit. Ok so help me understand why a 30 amp circuit is required but I need to put a 50 amp receptical on the wall? I know that isn't code. What am I missing?

 

[ItsNemo]

Nothing against code to put a higher amperage receptacle on a circuit that's got a lower amperage breaker. As long as all components downline of the breaker are rated at or higher than the amperage of the breaker, you're good.

(Minus a few exceptions I'm sure).

 

[ishiboo]

For the difference in cost though to go to 10awg wire that is rated fully for 30 amps, there's almost no point in under sizing.

People are just a lot more likely to have #12 or #14 at home and/or end up using the rest of it in the future than #10. The welder won't know the difference.

 

[climb.on]

But that's what I don't get. Why are we talkng about wire gauges that don't match a 50amp plug? What are they putting a 50 amp plug on this thing?

 

[sberry]

The 50A plug is so it can run on common 50A welder circuits that have been in place for decades, makes it universal to this type of welder. A 10 wire 30 is ideal foir this machine, simply change the recept to a 6-50. The 14 is a minimum and when it is it needs to be limited to 30 breaker, 12 or better can be 50 and a lot of the 6-50 recepts are listed for 10 wire. The 10 makes such a better connection and certainly gives these little machines all the help they can get. You already have it in place, this is as good as it gets.
Do not hold out, buy this, get it installed as fast as you can and get some use from it. It is a very good machine, good price and you should have absolutely no buyers remorse about this, not one bit, they last decades.

 

[matt_i]

No need to quote out of your head... the owners manual has the info he needs. 30A with #14 wire.

Very good point But #14...is what I use for a LED lighting circuit. I would feel better late at night knowing I had wired with #10.

When I was young and there was no internet, I got my first small Lincoln Mig Welder, looked at the 50A plug and ran #6 awg to the outlet on a 50A breaker.

Eventually in life I upgraded welders and the extra ampacity would have been helpful.

 

[sberry]

Not many really think the 14 is a great idea and there actually needs a pigtail to the recept for the termination listing. A 10 will support a stick buzzer too, the only factory 50 cord machine needs to be bigger is some of the 250 migs, 252 and even then it would be ok with 035/c25.

 

[ItsNemo]

But that's what I don't get. Why are we talkng about wire gauges that don't match a 50amp plug? What are they putting a 50 amp plug on this thing?

Because the breaker will trip at 30 amps which is safe for 10awg wire if you try to pull 50 amps through the 50 amp plug.

Most wire is rated for 90c in temperature, with a welder not running 100% duty cycle you won't hit 90c in undersized wire (14 awg) before the welder will hit it's duty cycle and allow everything to cool. To do this though the plug has to be labeled for welder use only and you can't plug anything else into it. You also don't want to try running a big honking 350a machine wide open spray arc for an hour on it either. Hence, better to just use the correctly sized wire for the breaker and not have anything to worry about.

 

[climb.on]

Thanks that makes more sense and gives me a better an understanding I'll just make up an adapter for the welder so I can use it in any of my (4) 30a/240v outlets around the shop.

 

[sberry]

You might change one out for a home for it, possibly make the adapter an extension. What else do you use on these circuits?

 

[climb.on]

You might change one out for a home for it, possibly make the adapter an extension. What else do you use on these circuits?

Yes, this is proving to be more challenging than i hoped. I thought I would just make an adapter, but the only NEMA 6-50R plug end I can find is $45 plus shipping. I'll end up with $70-$80 in a dang adapter, but it still might be my best option.

I could change out one of the 30amp receptacles and dedicate it to the welder, but I will surely need to use it somewhere else if I do that.

I have a table saw and a planer that both use the 240v/30a circuits.

 

[ishiboo]

Yes, this is proving to be more challenging than i hoped. I thought I would just make an adapter, but the only NEMA 6-50R plug end I can find is $45 plus shipping. I'll end up with $70-$80 in a dang adapter, but it still might be my best option.

I could change out one of the 30amp receptacles and dedicate it to the welder, but I will surely need to use it somewhere else if I do that.

I have a table saw and a planer that both use the 240v/30a circuits.

There is no such thing as a 6-50R plug end. R means receptacle, P means plug. I think you mean a cord end.

I made my adapter simply using a surface-mount receptacle like this. Another option would be to use a steel box with a regular receptacle in it.

 

[Falcon67]

Same on my RV - it's a "50A" cord and plug, but I ran a 30A circuit - cheaper, it doesn't pull anywhere near that kind of draw sitting parked. We can run the whole thing - air, battery charger, lights, etc at the track on a 5500 genny so why overkill it. Same on a MVP210, I'd run a 30.

 

[BukitCase]

Dunno where you got your pricing, sounds kind of high -
https://www.homedepot.com/s/nema%206-50?NCNI-5

Also, on code - NEC does NOT care what you plug into a receptacle, only that the WIRE IN THE WALL is protected by the BREAKER (30 amp breaker, 30 amp wire, aka #10) - as long as you maintain THAT criteria, you can plug ANYTHING into that receptacle - if you get too "greedy", (like later getting a 250 amp class welder and using it on 3/4" plate) the breaker will stop you...

And yeah, there's a "welder exception", where the wire can be smaller ONLY if that circuit is JUST for a welder - but that is NOT a good idea for residential, NON-labeled wiring - what's to stop the NEXT owner from running a 6kw, 240 volt HEATER on your #12 or #14 wire and "getting more heat than he wanted" ?? (As in, fire in the wall...)

BTW, if your 30 amp receptacles look like this
https://www.homedepot.com/p/Leviton...ight-Blade-Plug-Black-R50-00931-000/202077682
Then that's half of your adapter (blades can be inserted either way) - the female is on the FIRST link, then find a box that'll fit the COVER on the first link... Steve

 

[wyliesdiesels]

But that's what I don't get. Why are we talkng about wire gauges that don't match a 50amp plug? Why are they putting a 50 amp plug on this thing?

Because larger welders use 50a circuits and many shops already have 50a outlets. So the manu. puts 50a plugs on it so you can use on it a 50a circuit you may already have.