Welding Tips and Tricks

I have an eastwood mig250
I am looking into getting a gen for it. To run on 240v at 47 amps I will need a 12,000 watt gen. My question is do I need 12k starting or running watts? Thanks

Running. "Starting" is kinda useless as it's just a "100 millisecond" kind of rating.

Havoc0122 wrote:I have an eastwood mig250
I am looking into getting a gen for it. To run on 240v at 47 amps I will need a 12,000 watt gen. My question is do I need 12k starting or running watts? Thanks

why do you need a 12K gen, my Onan in my motorhome puts out 51.5 amps with 6500 watt output

Deano56 wrote:

Havoc0122 wrote:I have an eastwood mig250
I am looking into getting a gen for it. To run on 240v at 47 amps I will need a 12,000 watt gen. My question is do I need 12k starting or running watts? Thanks

why do you need a 12K gen, my Onan in my motorhome puts out 51.5 amps with 6500 watt output

You have 240V in your motor home? Impressive

By my calculation you only have half of what the OP needs.

Oscar wrote:Running. "Starting" is kinda useless as it's just a "100 millisecond" kind of rating.

Thanks Oscar. Looks like I'll be spending a pretty penny.

Deano56 wrote:

Havoc0122 wrote:I have an eastwood mig250
I am looking into getting a gen for it. To run on 240v at 47 amps I will need a 12,000 watt gen. My question is do I need 12k starting or running watts? Thanks

why do you need a 12K gen, my Onan in my motorhome puts out 51.5 amps with 6500 watt output

Yeah I need 12000 running watts.


Any suggestions on brand? Trying to keep it around 2grand..

Oscar wrote:Running. "Starting" is kinda useless as it's just a "100 millisecond" kind of rating.

Thanks Oscar. Looks like I'll be spending a pretty penny.

Deano56 wrote:

Havoc0122 wrote:I have an eastwood mig250
I am looking into getting a gen for it. To run on 240v at 47 amps I will need a 12,000 watt gen. My question is do I need 12k starting or running watts? Thanks

why do you need a 12K gen, my Onan in my motorhome puts out 51.5 amps with 6500 watt output

Yeah I need 12000 running watts.


Any suggestions on brand? Trying to keep it around 2grand..

I think you need to worry about a few more factors than running watts. The welder you mentioned is an inverter welder. It is not likely to react well if the power from the generator is not clean (i.e., if the THD is above 5%, if the voltage regulation isn't tight and if the AC output is something other than sine wave). Also 47 amps is the running amperage draw of the welder at rated output. I looked but I couldn't find what the max inrush current for that welder is. If it is significantly higher than 47 amps, you will need a larger generator.

Don't underestimate the effect of "clean power" (not my term but you see that used on a lot of generator websites). My old home standby genny was an 8000 watt running/13000 watt starting Briggs and Stratton. The THD wasn't listed anywhere, but I have seen estimates that it was in the 20% range. That genny would barely start my 240v, 3 wire well pump which had an inrush current of approximately 13 amps per leg according to my clamp on ammeter (so something like 6300 watts not including any power factor correction?). And it made all the modern appliances (loaded with electronics) hum in a weird way. I replaced that unit with a Champion 7000/8750 watt inverter unit (sine wave/clean power supposedly) and it starts the well pump with much less effort (doesn't bog down the way the old unit did) and none of my appliances run any different than when on grid power.

Louie1961 wrote:I think you need to worry about a few more factors than running watts. The welder you mentioned is an inverter welder. It is not likely to react well if the power from the generator is not clean (i.e., if the THD is above 5%, if the voltage regulation isn't tight and if the AC output is something other than sine wave). Also 47 amps is the running amperage draw of the welder at rated output. I looked but I couldn't find what the max inrush current for that welder is. If it is significantly higher than 47 amps, you will need a larger generator.

Don't underestimate the effect of "clean power" (not my term but you see that used on a lot of generator websites). My old home standby genny was an 8000 watt running/13000 watt starting Briggs and Stratton. The THD wasn't listed anywhere, but I have seen estimates that it was in the 20% range. That genny would barely start my 240v, 3 wire well pump which had an inrush current of approximately 13 amps per leg according to my clamp on ammeter (so something like 6300 watts not including any power factor correction?). And it made all the modern appliances (loaded with electronics) hum in a weird way. I replaced that unit with a Champion 7000/8750 watt inverter unit (sine wave/clean power supposedly) and it starts the well pump with much less effort (doesn't bog down the way the old unit did) and none of my appliances run any different than when on grid power.

Thanks this helps a lot

Luckily the Genny I have been looking at is of the latest tech. Sine wave, low thd, etc.

https://a-ipower.com/product/sua15000ec ... generator/

Havoc0122 wrote:
Luckily the Genny I have been looking at is of the latest tech. Sine wave, low thd, etc.

https://a-ipower.com/product/sua15000ec ... generator/

Wow, that's a beast! I wonder what it weighs.

24hp OHV Twin Cylinder Engine / 85 db at 23 feet.

Its not going to be pleasant to be around that machine when running.

Yup, that looks like a good one .

Louie1961 wrote:

Havoc0122 wrote:
Luckily the Genny I have been looking at is of the latest tech. Sine wave, low thd, etc.

https://a-ipower.com/product/sua15000ec ... generator/

Wow, that's a beast! I wonder what it weighs.

24hp OHV Twin Cylinder Engine / 85 db at 23 feet.

Its not going to be pleasant to be around that machine when running.

It weighs almost 400 net. Yeah I have a box of ear buds already haha. Thanks for the tips everyone.

This is agood one too

https://m.northerntool.com/shop/tools/p ... _200756275

Ballistic308 wrote:

Deano56 wrote:

Havoc0122 wrote:I have an eastwood mig250
I am looking into getting a gen for it. To run on 240v at 47 amps I will need a 12,000 watt gen. My question is do I need 12k starting or running watts? Thanks

why do you need a 12K gen, my Onan in my motorhome puts out 51.5 amps with 6500 watt output

You have 240V in your motor home? Impressive

By my calculation you only have half of what the OP needs.

sorry folks, my generator is 120 volts with 51 amps, our ac units run off of 120 volts