What size generator do I need

[Galej]

I have a very old, but very large Lincoln welder, that requires 240. I don't at this time know exactly it's wattage requirements. I see conflicting information on the web regarding what size of generator I would need to run it. One says 9000 running watts is enough, another says I need at least 15,000. That's a big difference! Any other input would be great, thanks

[SweetMK]

The main thing that will determine generator size is how the welder will be used,,
If you only TIG weld at 30 amps,, the watt requirement will be VERY low,, like only 3,000 watts,, or less,,
100 amps of welding will mean the welder will draw much more wattage,, maybe 4,000 or 6,000 watts,,

If you are gonna stick weld GIANT rods,, the size generator is going to grow,, a LOT!!

[Louie1961]

The main thing that will determine generator size is how the welder will be used,,
If you only TIG weld at 30 amps,, the watt requirement will be VERY low,, like only 3,000 watts,, or less,,
100 amps of welding will mean the welder will draw much more wattage,, maybe 4,000 or 6,000 watts,,

If you are gonna stick weld GIANT rods,, the size generator is going to grow,, a LOT!!

I have to disagree. Some Lincoln transformer machines are so inefficient that even at low amperage they require a rather large generator. https://www.lincolnelectric.com/en-z...ze-detail.aspx

Keep in mind this is the guidance for their consumer grade machine that you can buy at Home Depot, not the 300+ pound Idealarc behemoths. It sounds like maybe the OP has one of the Idealarc machines. I have no idea what size generator is needed to run one of those, but I doubt it is going to be less than 10K watts.

[smithdoor]

Need to know size of welder.?
What plan to weld?
Do you have a generator?
Odds are the 9,000watt well work.

Dave

I have a very old, but very large Lincoln welder, that requires 240. I don't at this time know exactly it's wattage requirements. I see conflicting information on the web regarding what size of generator I would need to run it. One says 9000 running watts is enough, another says I need at least 15,000. That's a big difference! Any other input would be great, thanks

[Louie1961]

The quality of the generator is also going to play a role here. If you have a generator with a weak voltage regulation system that doesn't produce clean power (i.e., low total harmonic distortion), it is going to take a LOT more generator to run the welder. I had this problem with my well pump. My 13K Briggs generator with 20% THD could barely start my well pump. My 6.5K inverter generator starts it with no sweat.

[SweetMK]

I have to disagree. Some Lincoln transformer machines are so inefficient that even at low amperage they require a rather large generator. https://www.lincolnelectric.com/en-z...ze-detail.aspx

Keep in mind this is the guidance for their consumer grade machine that you can buy at Home Depot, not the 300+ pound Idealarc behemoths. It sounds like maybe the OP has one of the Idealarc machines. I have no idea what size generator is needed to run one of those, but I doubt it is going to be less than 10K watts.

My friend borrowed a Miller Thunderbolt AC only machine that I had at the time,,
He successfully welded a trailer with that welder,, using a 4,500 watt (surge) generator,, so, actual real life welding says a small generator will work.
The little buzz box welders connected to 10HP gas engines will weld 1/8 inch rods,, I had one of those,, also,,
A 10HP Kohler K engine can not produce 10K watts,, (maybe 4,500 watts??) and heck, that engine was hardly laboring when welding 1/8" rods,,,

LOTS of people weld in their home on a 30 amp breaker, if using small rods,, bigger rods need a bigger breaker,,
I have also done that with the Thunderbolt,,

[G-ManBart]

I have a very old, but very large Lincoln welder, that requires 240. I don't at this time know exactly it's wattage requirements. I see conflicting information on the web regarding what size of generator I would need to run it. One says 9000 running watts is enough, another says I need at least 15,000. That's a big difference! Any other input would be great, thanks

Without knowing the model welder there really isn't any way we can help other than guess.

[Broccoli1]

My friend borrowed a Miller Thunderbolt AC only machine that I had at the time,,
He successfully welded a trailer with that welder,, using a 4,500 watt (surge) generator,, so, actual real life welding says a small generator will work.
The little buzz box welders connected to 10HP gas engines will weld 1/8 inch rods,, I had one of those,, also,,
A 10HP Kohler K engine can not produce 10K watts,, (maybe 4,500 watts??) and heck, that engine was hardly laboring when welding 1/8" rods,,,

LOTS of people weld in their home on a 30 amp breaker, if using small rods,, bigger rods need a bigger breaker,,
I have also done that with the Thunderbolt,,

Real world does matter.

But the 30amp CB at home is backed up by the Power Plant generator

generator power is a wee different due to the size - small- of the generator. They do not like big kicks to the nutz and some just do not recover from the initial surge in power to run a welder.

The welding manufactures are stating the best size genset to use for optimal performance with their welder.

[Sberry]

The gen on welding machines have way more poop than they list. But it would be cheaper to buy a import inverter that a cheap genset would run.

[Sberry]

Not only that modern inverter will eeld from 120v. Lots more places you can weld but 1/8 6011 & 3/32 lo hy run toasty can do a lot of work and nothing easier than 2 pass 7018 with that small rod. Half nuke plant built with it.

[ttoks]

The gen on welding machines have way more poop than they list. But it would be cheaper to buy a import inverter that a cheap genset would run.

Exactly this, generators get expensive real fast beyond about the 6000 watt range, I paid $1000 for a 9kva 7200 surge watt 5% THD generator, going up to a 11k watt triples the price, and above 13k watts you start looking at used engine drive welder price, where as a 4.5k watt generator will run a cheap 140 amp inverter and the welder and generator will be cheaper than a generator to run the old school welder you have.

[MinnesotaDave]

I plugged a miller dialarc 250/250 into my 8,000 watt generator (miller bobcat 225nt) and it would only run 3/32" 7018 at about 100 amps without popping the breaker.

My inverter welders run on much lower watt generators.

[Galej]

Thank you all so very much for your quick responses regarding my generator query. But I do owe you an apology! I finally got in to see the generator (it's in a neighbor's storage room) and it is not a Lincoln, but a Craftsman..! I'm guessing it's from the '60s, but was unable to find out online. Model number 113.20170
The information on the front is as follows..
A few of my numbers may be off due to difficulty reading
PRimary:.
Volt 230. Max 30 arc volts
Rated amps 37. CYC (?). 60
Phase 1 Max KW 7.2
Max amps, short circuit 71
SECondary
Max amps 200. 30 arc volts, 30%, duty cycle
Rate amp 160, 30 arc volts, 50% duty cycle
Temp rise 90° c
Max open circuit volts 80

I plan to use either 6011, or 6013 rods for the vast majority of my work. Thank you thank you!

[G-ManBart]

Thank you all so very much for your quick responses regarding my generator query. But I do owe you an apology! I finally got in to see the generator (it's in a neighbor's storage room) and it is not a Lincoln, but a Craftsman..! I'm guessing it's from the '60s, but was unable to find out online. Model number 113.20170
The information on the front is as follows..
A few of my numbers may be off due to difficulty reading
PRimary:.
Volt 230. Max 30 arc volts
Rated amps 37. CYC (?). 60
Phase 1 Max KW 7.2
Max amps, short circuit 71
SECondary
Max amps 200. 30 arc volts, 30%, duty cycle
Rate amp 160, 30 arc volts, 50% duty cycle
Temp rise 90° c
Max open circuit volts 80

I plan to use either 6011, or 6013 rods for the vast majority of my work. Thank you thank you!

Those numbers all make sense. Did you notice anything about AC or DC output? I'm guessing it's an AC unit as there are several part numbers close to that which were AC only.

Regardless, it's rated as pulling 37A when the output is 160A, but that's a bit more than you would need to run common 1/8" 6011 or 6013. The typical max for those two rods is around 125A, so it wouldn't be pulling 37A. At 37A you would need a generator that could handle a running load of 8,500W so you might be able to get by with something in the 7,000 range (running, not peak). The good thing is that you aren't likely to hurt the welder by not having enough power...it just won't weld properly. With some of the new machines I would be worried about a marginal generator or one that didn't put out really clean power.

[albrightree]

SearsPartsDirect.com

Model #11320170 Craftsman ac arc welder



No Parts seem to be available from Sear's anymore, maybe century tool, or century welding have a manual with some info.

[Kelvin]

Most of my 1/8" 6010 I run at 72A, at least according to the DRO on my Sync250, though you really can't trust what's reported, I don't think.

[Willie B]

Have you said why you need a generator?

37 amps X 240 volts says 9KW generator, but one should avoid loading a cheap generator to full rating.
The picture looks to be a MIG or flux core machine.

[G-ManBart]

The picture looks to be a MIG or flux core machine.

Yeah, I suspect the Sears parts page doesn't always match the correct picture with vintage items...just a guess. It's definitely a more modern wire welder pictured.