Running Welders off Generators

[Furu]

I know that the newer style Inverter Welders should only be run off "clean" pure sine-wave generator power.
I know that one specific poster has had great luck and loves his Honda EU2000I generators and that is not what I am asking about as they are only 120volt capable.

My question is about 240 volt 10 KW generators that have a modified sine-wave output and older welders that have transformers in them not the inverter technology.

Is there a problem running transformer welders off this not pure sine-wave output?

Maybe Mark will chime in as I think he has specific knowledge in this area.

 

[MinnesotaDaveChalmers]

If you find out the THD and call the welder manufacturer they should be able to give a definitive answer.
I have an older Generac 5000/6250 and Miller told me it was fine to run my Maxstar 150s off it.
It ran great on 240v (likely due to power factor correction in the welder smoothing out the power)

Lincoln told me not to run my Invertec v250-s off that source as the voltage fluctuated out of the welders +/- for input voltage.

My older 120v migs ran terrible off that power source (an old Craftsman/Century and a small Lincoln flux core only machine)
I didn't dare plug in my millermatic 210 and try that - too expensive

 

[Furu]

If you find out the THD and call the welder manufacturer they should be able to give a definitive answer.
I have an older Generac 5000/6250 and Miller told me it was fine to run my Maxstar 150s off it.

Without an O-scope I don't know if I could get that. I do not have an O-scope either. Generac manuals and specs that I have seen do not seem to present that data. Either they do not want the consumer to have it or they do not think it is anything that the consumer is interested in.

 

[Sodo]

Funny you posted this a couple hours before my generator post. These two posts are different but may have some overlap.

It is my understanding that a transformer could not care less about the power it receives, it just transforms whatever it gets. But that's not to say the 'weld' doesn't care - I can't offer any knowledge about that part. Also a generator that creates electricity by a turning armature is (almost by definition) outputs a "pure sine wave", but the frequency is determined by the gas motor's RPM. So if the motor pulls down, the frequency reduces accordingly.

I got a little nervous from your note (I have an inverter welder MultiMatic200) so I called MillerWeld Tech suppt. They said the MM200 is generally not affected by dirty power, so good news for me anyway.

 

[MinnesotaDaveChalmers]

Without an O-scope I don't know if I could get that. I do not have an O-scope either. Generac manuals and specs that I have seen do not seem to present that data. Either they do not want the consumer to have it or they do not think it is anything that the consumer is interested in.

The Generac XP series is the one with low Total Harmonic Distortion <5%

Most companies I've seen in recent years have been listing THD (only if it's good) since there are so many sensitive electronics being run now days.

They will tell you if you ask since companies would rather you not wreck electronics and then blame them

 

[nova3930]

I can't speak in general, but specifically I have yet to be able to get a good penetrating weld on anything with my older coleman 7.5kw generator and the old miller thunderbolt buzzbox I have.

 

[MinnesotaDaveChalmers]

I can't speak in general, but specifically I have yet to be able to get a good penetrating weld on anything with my older coleman 7.5kw generator and the old miller thunderbolt buzzbox I have.

Buzz boxes are real power hogs when it comes to Inrush Current.

Check out what Lincoln says about running their version off a generator:

Question: It appears that a 5000 or 6000 watt 230 VAC generator is large enough to operate my AC/DC 225/125 welder using a 1/8 inch diameter E6010. Please confirm.

Response: It does appear (if you do the math) that you should be able to use 1/8 in. and smaller diameter electrodes with an AC/DC 225/125 powered by a 5000 or 6000 watt generator. Unfortunately, the design of the transformer on the AC/DC 225/125 is not efficient enough to be powered by a small generator. If you try and weld with this combination you will most likely experience the electrode being hard-to-strike and also the electrode frequently sticking to the work.

If you are fortunate to establish an arc, the arc will tend to pop out frequently. Also, there will not be adequate heat input to the work, resulting in low weld quality (poor fusion), and poor bead appearance.

To successfully run your AC/DC 225/125 welder you would need a minimum of a 15,000 watt AC generator.

 

[nova3930]

Buzz boxes are real power hogs when it comes to Inrush Current.

Check out what Lincoln says about running their version off a generator:

You just confirmed what I had suspected but had never properly investigated. Even a 1/8" 6013 is a nightmare to get to strike on the generator and has even worse penetration than normal. Plug it into wall power and it burns like crazy.

 

[Furu]

The Generac XP series is the one with low Total Harmonic Distortion <5%

Most companies I've seen in recent years have been listing THD (only if it's good) since there are so many sensitive electronics being run now days.

They will tell you if you ask since companies would rather you not wreck electronics and then blame them

I have a Generac 10000EXL that I have owned since 1999. It is not the XP series which is much newer than mine.

It is interesting that if different volt meters are hooked up to an outlet at the same time you can get different voltage readings because different volt meters calculate/measure voltage differently. Thus I know the waveform is not pure.

 

[MinnesotaDaveChalmers]

You just confirmed what I had suspected but had never properly investigated. Even a 1/8" 6013 is a nightmare to get to strike on the generator and has even worse penetration than normal. Plug it into wall power and it burns like crazy.

That would be frustrating to the point of pushing the welder down a hill and lighting it on fire....:mur:

I was pleasantly surprised how nicely my little maxstar worked on a generator - new technology makes me uneasy...and I still consider inverters to be black magic voodoo

My favorite welder is my 1963 Airco stick/tig - 900 lbs of awesome!!

 

[MinnesotaDaveChalmers]

I have a Generac 10000EXL that I have owned since 1999. It is not the XP series which is much newer than mine.

It is interesting that if different volt meters are hooked up to an outlet at the same time you can get different voltage readings because different volt meters calculate/measure voltage differently. Thus I know the waveform is not pure.

That is very interesting, never tried that before. Do they read the same when plugged into the same house outlet?

....I'm gonna have to start trying that now

 

[nova3930]

That would be frustrating to the point of pushing the welder down a hill and lighting it on fire....:mur:

Oh it was. I'm no master welder, not by a long shot, but prior to I could always strike and weld metal with a 6013. The things are darn near idiot proof even if they don't penetrate well.

But I was in the position of having broken my skid steer forks in the middle of the land we were clearing for our new house, with no power and had to get them back together. After fighting with it for a hour, the neighbor moseys over and informs me that he's got a nice Millermatic 252 MiG and oh BTW he welds professionally at the United Launch Alliance rocket plant up the highway and would be happy to weld them up for me. :mur:

I promptly carried the forks across the street to his place and let him go to work while I went for an after-the-job-is-done 6 pack. :drink:

 

[Big Barn]

I promptly carried the forks across the street to his place and let him go to work while I went for an after-the-job-is-done 6 pack. :drink:

That without a doubt is the best welding post I've read today

Terry

 

[MinnesotaDaveChalmers]

That without a doubt is the best welding post I've read today

Terry

Me too
:drink:

 

[nova3930]

LOL, I'm not too proud to admit when it's time to pay the man rather than fumble through as an amateur, even if payment is a frosty adult beverage.

 

[Furu]

That is very interesting, never tried that before. Do they read the same when plugged into the same house outlet?

....I'm gonna have to start trying that now

Yes down to the 0.1 volt decimal point. As was explained to me it is because of the method of measurement. Cheap voltmeters vs not so cheap voltmeters.

V (rms) vs V (pep) Cheap AC voltmeters will just measure the peak voltage, and scale the reading as if it were a perfect sine wave. More to it than that but that is the general idea.

I also find on my Honda Inverter generators EU2000I that they read the same voltage on each(because it is a pure sine wave)

 

[dragoneggs]

Great topic Furu! I am also wondering what I can manage with my Honda EU3000iS which I use for backup power to the house for the essentials. I have a mechanical interlock so I can directly feed my service panel. Absolutely love this generator and it can be paired with another for a total of 6000watts. Dang expensive but by far the best generator I have used. Wondering if anyone has an idea of material thickness I could weld with 3000watts and 6000watts??? Oh and yes it is only 110v as far as I know.

 

[Soundguy]

Buzz boxes are real power hogs when it comes to Inrush Current.

Check out what Lincoln says about running their version off a generator:

I have a 12.5k northern tool pto generator mounted on a carry all / platform, and have had my hobart 235XL AC mounted with it when I was building the farm up before we had power run out here. I used to to weld on gates and such or power up the well. Never tried high settings.. but 6011 at 100a or so and on 1/8 rods ran just like it was on line power. I realize much of that has to do with the tractors governor ability to maintain rpm stability under load too... and not so much the generator itself or the welding machine..e tc.

just tossing that out as an observation of what i have experienced on my farm for light welding and water pump / power tool usage ( skill saws, 1/2" drills, etc.. ), and not a endorsement of any other specific suitability for use.. etc.

 

[Sodo]

Great topic Furu! I am also wondering what I can manage with my Honda EU3000iS which I use for backup power to the house for the essentials. I have a mechanical interlock so I can directly feed my service panel. Absolutely love this generator and it can be paired with another for a total of 6000watts. Dang expensive but by far the best generator I have used. Wondering if anyone has an idea of material thickness I could weld with 3000watts and 6000watts??? Oh and yes it is only 110v as far as I know.

I think 3000iS has a 230v outlet. Miller Tech said to weld 3/8" with the MultiMatic200 I'd need 7200W. I don't know how the 211 would behave. My pair of Honda EU2000i can weld on the 3/16" preset, but the generator overspeeds to get it going - tells me it's over the limit. I suspect with a single 3000iS you will be in the 14ga range maybe more(?) On 6000W it sounds like you might get to 5/16. A 2nd 3000iS is a lot of money, and another 76 lbs too but they are quiet!

 

[jwmorris]

I have ran my maxstar (inverter welder) off of two different generators, the way I made sure they were close enough to 60 cycles was hooking one leg of the power from the generator and another leg off of "land" power, going to an incondesent light bulb.

If the cycles are off the light will "pulse" when they are balanced it will function as normal.

Adjust the speed of the engine and go "high" and "low" then set in the middle.

It worked for me and I didn't have to get out an oscilloscope.