Using generator for welder

   / Using generator for welder #1  

arkydog

Gold Member
Joined
Jun 16, 2002
Messages
365
Location
Arkansas
Tractor
kubota 3200hst loader and bh77 backhoe, allis chalmers 816 backhoe
I have to weld a winch at a remote location and the generator is a coleman 4000 watt (16.6 amp at 240 volts). The lincoln welder is A/C, DC. What is the highest setting I can safely use on the DC side for the 16.5 amp from the generator and what size diameter rod (probably 6013 or 6011) to weld 1/4" mild steel.

Is there a formula for figuring what the DC amp setting should be for the amp input from the generator?

Thanks!

arkydog
 
   / Using generator for welder #2  
That doesn't sound like a happy combination to me /forums/images/graemlins/frown.gif
I have a little 220v welder than I run a 30a breaker on just for the light stuff like 11 gauge.I pop the breaker quite a bit at 100 a.Anything else and I'll drag out the Lincoln 225 and it runs a 50a breaker.Not an expert by any means but I'd be suprised if you can run 50 a at the welder without blowing the breaker on the genset.
 
   / Using generator for welder #3  
You should be able to run over 400 amps with your generator. Most AC welders use around 30 volts AC for welding voltage.
When using a generator to run a welder. I have had trouble getting a arc started. If you have auto idle on your generator turn it off. It may help.
 
   / Using generator for welder #4  
A few years ago at a previous job we had to install a barn cleaner chute before the hydro was installed. Superviser rented a 6500 watt generater for the welder. Long story short it was teribly undersized, couldn't run a bead more than 1/2 inch and breaker would blow. Took hours longer just to get supports in place enough to hold till hydro was put in and proper job could be done. I'd say forget the 4000.
 
   / Using generator for welder #5  
My first homemade welder was a 24volt 25 amp transformer that had a 115ac input.
I found that I could weld 1/4" stock if I used 1/16 or 3/32 6013 rod and more passes.
Striking an ark was tricky due to the lower voltage but it did the job.
I needed to use a 25 amp slo blo fuse.

The hammond is HD industrial transformer so it stood up quite well for many years until I could afford a real buzz box.

Fixed many a kids bike and stuff and developped techniques that were fine tuned for when I had a real welder.

The main problem was sticking rods (and blown fuses) due to low voltage but otherwise it performed quite OK.

ps: I still , sometimes use that old setup rather than tote the buzz box to the job for the odd little 'tacking job'

<font color="blue"> formula:watts=volts X amps </font>


Most welders will have an open circuit voltage of 70 or so volts.

4000watts/70 volts=57amps
So, in theory, you could weld with a rod that uses less than 57 amps.

Check the rod amperage tables to find a matching rod.

Off of the top of my head, I suspect 3/32" 6013 is OK but then you'd have to make a few passes.
I think 1/8 rod would draw too much current.

Basically, use your welder on 240 and try it with small rods that draw less than 60 amps.
The worst that'l happen is you will pop the generator breakers if you draw too much current.
 
   / Using generator for welder #6  
My 6500W, 30A generator runs my Hobart mig okay, and it does manage my son's giant Lincoln, but we've never done anything over 3/16. The generatot is taxed when running my son's mig.
 
   / Using generator for welder #7  
Biggest problem for using welders on gensets is big reactive power. 4000W will be enough for welding with 120-150Amps (120-150 x 25V arc voltage), but problem is that transformer "sucks" more, as you calculated, and will drop generator voltage.
You can solve a problem by connecting capacitor from single phase motor (up to 200uF/400V) in paralell with welder to decrease inductive current /forums/images/graemlins/wink.gif

If you have MIG welder, use it, as it works better on gensets (different transformer characteristics) or lease an inverter rod welder.
 
   / Using generator for welder #8  
Don't know about the DC part of it but I use a 4.5KW Onan to power my 225 Lincoln all the time, I just use 3/32 rods such as 6013, 7018 and make multiple passes. If the gen breaker trips you let it cool and take shorter passes. I do believe though that a 4kw Coleman is a little light for your job. Any chance of renting/borrowing a bigger unit, or take lots of breaks while welding?
 
   / Using generator for welder
  • Thread Starter
#9  
Thanks for all the replys! The winch is on a boat dock with access by 4 wheel drive only and there is no electricity, only generators. I tried my 110 Lincoln mig, but with the wind and breeze its just too hard to get a good weld, even built shelter around but deck boards have too much space between them. Thats why I have to use a stick welder.

I dont want to borrow someones generator because of the chance of breaking or damaging it, just dont like to borrow tools. I have always said you break it, you bought it!

Hopefully only popping the breaker is the only damage I will do to my generator.

Thanks

arkydog
 
   / Using generator for welder #10  
i am an iron worker by trade. your best bet would be to rent a larger generator, rental units are pretty rugged and a couple extra bucks for rental insurance would protect you from any breakage(should any occur). the 4000 watt coleman is a little light. if you rent the larger unit, use a 1/8 7014 rod. if you must use the 4000 w machine, try a 3/32 7014 rod,it's a fast deposit rod, and maintains a stable, easy start arc....
 
 
Top