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50A@240v generator - what would you get?

3K views 27 replies 11 participants last post by  balrog006 
#1 · (Edited)
Been thinking about getting a portable generator capable of running my MIG welder at full output (even though that's silly :cookoo: ).

9KW generators seem to run about a grand and 11KW seem to bump that up to $2K. 9KW is 37.5A at 240 and likely able to produce the needed juice to burn in rods, but I really want to run a MIG and avoid the smoke/dust/clean-up, not to mention I can weld as long as I want with my power supply and I have an extra feeder I can bring up North and leave there with the generator.

I don't have utility power on site and likely won't for long enough to make this purchase viable (plus they're talking $10K just to get to my high ground and I'm not ready to plunk that down). $1K vs 2K is still a big hit in the wallet.

Being able to weld 1/4" with .035 wire in a single pass is pretty much my minimum. I'm talking about long continuous seams on cargo containers, so my little Hobart 120v is a no-go (the 8" spools aren't cost effective for starters, and I don't want to have to bevel 20' pieces of bar stock to get a good joint).

What's out there that you guys would recommend?
 
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#2 · (Edited)
Just a quick calculation but 50 Amps x 240 Volts = 12,000 Watts. You might have a problem running a 9-10K Watt gen set under a continuous load? Under these conditions I'd want a very good quality gen set as opposed to the typical intermittent duty, box-store, homeowner unit. :hi:

Just did a quick search and found something to consider. This unit would probably get you by:

https://www.northerntool.com/shop/tools/product_200467369_200467369

I'd hate to see you spend less to get something that was insufficient to handle the load, trip breakers and ultimately overheat and wipe out the brushes and commutator.
 
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#3 ·
Been thinking about getting a portable generator capable of running my MIG welder at full output (even though that's silly :cookoo: ).
Is your MIG welder a transformer-based unit or does it use an inverter? Transformer based units typically need more KW. Check with the manufacturer for generator recommendations.

I have a Longevity 250A stick welder that is inverter based and using my Honda EU6500 (6500 watt) I am able to crank the welder up just shy of 200A before the generator starts to complain. So far this has been more than enough to weld just about anything I need to.
 
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#4 ·
I agree with Superglide, a bit more robust unit like he linked will likely be easier on your whole setup and more reliable than say a 12K unit by Generac or Champion -if Champion makes one that large, I know Generac does.

Another option I’d look very hard at since your probably going to end up spending :gizmo: is a diesel unit. I’d think something like this Perkins USA made would suit your needs and any future needs very well. Perkins Diesel Generators* Made in USA with pride

Heck you could find a used unit that would likely outlive you for less :gizmo:
 
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#5 · (Edited)
Another option I’d look very hard at since your probably going to end up spending is a diesel unit. I’d think something like this Perkins USA made would suit your needs and any future needs very well. Perkins Diesel Generators* Made in USA with pride
For that kind of money he would be better off simply selling the MIG welder he currently has and getting something like a Miller Trailblazer. You would end up with a 12KW generator and a 300A multiprocess welder in a nice package for less than $6K.

I mean, he's talking about long continuous seams on cargo containers so something with a decent duty cycle will be needed.
 
#6 ·
If it were me, I'd scour the web to find a surplus Military MEP-003A or MEP-803A diesel generator. The data plate on them says they are rated at 10KW continuous but you can run them at 12-14KW for hours on end without problem. They're built to run for weeks on end too.

In my area there are several of them ranging from $2,000 to $5,500 listed on Craigslist. If you're willing to play the bidding game, you can find them on government surplus auction sites for less.
 
#7 · (Edited)
This is my welder, it's an inverter and puts out 300A on single phase depending on which version of the owners manual you look at (the earlier one says it'll do the full 425A but at 5% duty cycle): http://www.google.com/url?sa=t&rct=...59d834a1.pdf&usg=AOvVaw12LhIKCMjRT0JNuDnGwWYK

It's name plate max input amperage at 240v is 53A, but 300A in MIG needs some massive electrode wire and I'm not going to run that on these. The container I-beam flanges are 3/16" at most and the sides are 16 or 18ga (easily done with my Hobart, but brutally slow). I haven't probed what the corner posts are or top rail, but it's not going to take over 250A (which will weld 1/2"), so my machine will still be singing right along well under the full load input.

I might have totally lucked out and found a 15KW that's not putting out juice for $500. I have a buddy that's an electronics tech for Cummins Power Solutions small generators, so if I can't get it working I know he can and it might cost me some whiskey over the price of parts. I'm going to look at it tonight. :good2:
 
#9 ·
Hiya,

A buddy of mine picked up one of these a few years ago for his house generator, not all that portable out of the box but it will run forever at 12K output. :unknown:

Detroit powered Diesel generator
 
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#11 ·
Jeez Tom,

I had to laugh when I saw the gen set description "Residential Muffler" on a 71 series Detroit. Then again a 2-71 running at 1,200 rpm shouldn't make that much of a racket.

Surprised that they'd be running the engine at 1,200 rpm though. I wonder if it's geared down? DD's of that vintage usually don't make any power until ~ 1,800-2,100 rpm.
 
#14 ·
At $5K for a generator, I'd be looking at how much (exactly) for utility power. I've been told it'll be around 10K.

Even so, I might just rent one for the project or see if my buddy can get me a loaner from work. I'm getting a bad vibe off the 15KW people, like maybe it's not really rightfully theirs.
 
#16 ·
If a 6-71 purring doesn't give you a chubby, Viagra won't help either - you're dead! :laugh:


I think the 15Kw lady was just super excited to get the thing out of their way, and I misread that as "hot potato". Turns out they run a concession trailer and had it for events when utility power wasn't provided, but most places do. They fired it up one time and it ran but didn't make any juice.

I'm going to at least check it out.

My Cummins buddy says if the alternator is crap, they're not made in such a way as to be fixed. In that case, I'll use my 18Kw head on the engine and all is good. Looks like a decent engine from the service manual.
 
#18 ·
If a 6-71 purring doesn't give you a chubby, Viagra won't help either - you're dead! :laugh:
Here's one: https://youtu.be/mFEw6GTngyY

As far as the Jimmys go, I had a 2 cyl that ran at 1200 rpms and had a 20k gen end. A 6 pole gen end only needs 1200 rpm to make 60hz. 4 pole needs 1800.. 2 pole 3600. The slower the better. Mine was a 2-71 so she had a healthy bore.
Healthy bore? I'd say @ 71 c.i. per cylinder! Now that I think of it, the marine, industrial and construction versions of the X-71's were setup for lower, constant rpm operation.
 
#17 ·
I would either rent a tow behind welder/gen or scour the net for a good used one. I had a miller bobcat 250 on my svc truck. I could weld at 250 amps and had 10k of generator. They are a double wound generator end.
As far as the Jimmys go, I had a 2 cyl that ran at 1200 rpms and had a 20k gen end. A 6 pole gen end only needs 1200 rpm to make 60hz. 4 pole needs 1800.. 2 pole 3600. The slower the better. Mine was a 2-71 so she had a healthy bore. Was designed to power refer units on the railroad.

Sent from my LGL52VL using Tapatalk
 
#21 ·
Why the heck would I want to run an engine every time I wanted to weld something? I'm not getting into the portable welding game. I'm working on an off-grid job site until I have enough money to get the utility power brought in. Having a back-up generator is bonus.

I already have a honey of a 400A pulsed-MIG.
 
#22 ·
Most of the engine driven welders can also be used as a portable generator. It sounds like your goal is a temporary solution to get the job done. Do whatever makes the most economical sense. Even if you went the route of a USED unit like a Miller Trailblazer you can always sell it when the job is finished. They sell very well on the used market.
 
#23 ·
I don't want to tie that much money up in anything when all I need is a power source for the welding power supply I already have (which has the best arc of any MIG I've ever run btw).

Going to look at the Generac 15Kw at 2pm. :)
 
#26 ·
She didn't want to fire with lord knows how old of gas in it in 5F weather. Guy eluded to maybe needing a carb rebuild. Air filter was squeaky clean, but not "new", and the oil looked good so I'm pretty sure they were being honest about it's service history.

It's supposed to hit 30 Saturday, and I'm going to be up there for meeting my forester anyway. Might see what happens with fresh gas.
 
#28 ·
Even with fresh gas it may not fire from sitting or the cold-take some starting fluid-if you can get it to fire and warm up a little it may run on its own, if it’s going to run.
 
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