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!!