Welding off a portable generator

[STERLING351]

So i am replacing my fence on my property with 2-7/8 steel pipe for corner post and H-braces. In the past i have welded with a friends generator welder using 6011 1/8th rods at 90-100amps with good results. I was looking at a Powerhorse 7000w surge/5500w running generator ( https://www.northerntool.com/shop/tools/product_200664808_200664808 ). It has a L14-30 outlet so i found this ( Amazon.com : Conntek PL143 Welder Adaper Generator L14-3 Plug(4 Prong 3Amp) to NEMA 6-5R 5 Amp 25-volt Adapter Cord : Garden & Outdoor ) to adapt my welder to the generator. Do you think this generator will be enough for my needs, has anyone used Powerhorse in the past? They have good reviews.

 

[MinnesotaDaveChalmers]

Depends on the welder. For many small inverter welders it would likely be enough.

I've run my Thermal Arc 161 off my old 5000/6250 generator with good results.

 

[STERLING351]

Depends on the welder. For many small inverter welders it would likely be enough.

I've run my Thermal Arc 161 off my old 5500/6250 generator with good results.

I recently bought a Klutch st200iDV to use for this since it small and portable which makes it fit in the back of my polaris ranger next to the generator hopefull for ease of transport.

 

[MinnesotaDaveChalmers]

It's an inverter based machine so I'd bet it performs similar to my Thermal Arc on a generator.

You're only trying to burn at 100 amps so you won't be pushing the welder very hard.

I know a lot of people opt for 7500 watt continuous generators though.

 

[WranglerX]

On the Hobart Welding Forum (Weldtalk) , they recommend a generator with about 50% more capacity that welder needs.... So if input side of welder requires about 20 amps (4800 Watts) at 240 Volts AC a unit capable of about 30 amp (7200 Watts) surges is best (numbers here sort of arbitrary for example) ... The thinking is start up surge (each time arc is stuck) of welder puts addition load (surge) on generator and it may bog down if its too small (slow to recover), because the rotating parts do not have enough rotating inertia/mass to keep up with load needs... Granted new inverters welder are better load wise but having generator to small can be more of a pain and makes work more miserable...

Wish people would not post Northern Tool links till board software does away with VIGLINK link hijack...

Dale

 

[STERLING351]

On the Hobart Welding Forum (Weldtalk) , they recommend a generator with about 50% more capacity that welder needs.... So if input side of welder requires about 20 amps (4800 Watts) at 240 Volts AC a unit capable of about 30 amp (7200 Watts) surges is best (numbers here sort of arbitrary for example) ... The thinking is start up surge (each time arc is stuck) of welder puts addition load (surge) on generator and it may bog down if its too small (slow to recover), because the rotating parts do not have enough rotating inertia/mass to keep up with load needs... Granted new inverters welder are better load wise but having generator to small can be more of a pain and makes work more miserable...

Wish people would not post Northern Tool links till board software does away with VIGLINK link hijack...

Dale

So are you saying this welder is too small? I know at 200 amps output it requires 40amps input ar 220. I am unsure of exactly how much the draw is for 100amps output.

 

[MinnesotaDaveChalmers]

So are you saying this welder is too small? I know at 200 amps output it requires 40amps input ar 220. I am unsure of exactly how much the draw is for 100amps output.

My Thermal Arc 161 welds very well at 125 amps from my 15-20 year old 5000/6250 generac generator.

Rent a generator for half a day and try it out for peace of mind - that's only about $40 here.

 

[WranglerX]

So are you saying this welder is too small? I know at 200 amps output it requires 40amps input ar 220. I am unsure of exactly how much the draw is for 100amps output.

First ...

Watts are volts time amps...
240(v) x 10(a) = 2400 (w)


Amps are Watts divided by volts.
2400(w) / 10(a) = 240(v)

Take case of Lincoln tombstone welder, its a transformer welder.... Lets say at 100 amps it has a arc voltage of 24 volts...

Since welder is transformer model and for discussion we will say its a 10:1 ratio.... So 240 volts is stepped down through transformer to 24 (arc) volts, BUT this means as voltage is stepped down, amperage is stepped up (thank you Nicola Tesla) with a 1:10 ratio so a 100 amp output it relates to a 10 amp input....

Arc voltage and amperage needs to be calculated as to the conversion factor internal to welder (step down ratio)....

In your case you 200 amp output requiring 40 amp input (at 240VAC) would suggest you need a generator capable of a minimum of 9600 watts... IF you include the 50% factor you would want a generator capable of about 14400Watt

240(v) x 40(a) = 9600(w) (less 50% factor)

These are input values BUT everything changes when you adjust amperage (for electrode) up or down....

How ever if you are only welding at 100 amps you draw would be less (about 1/2 max draw) or about 4800 watt... So you would want a generator capable of about 7200 Watts (including the about 50% over wattage reserve factor)...

Hope I have not confused you more...

Dale

 

[STERLING351]

First ...

Watts are volts time amps...
240(v) x 10(a) = 2400 (w)


Amps are Watts divided by volts.
2400(w) / 10(a) = 240(v)

Take case of Lincoln tombstone welder, its a transformer welder.... Lets say at 100 amps it has a arc voltage of 24 volts...

Since welder is transformer model and for discussion we will say its a 10:1 ratio.... So 240 volts is stepped down through transformer to 24 (arc) volts, BUT this means as voltage is stepped down, amperage is stepped up (thank you Nicola Tesla) with a 1:10 ratio so a 100 amp output it relates to a 10 amp input....

Arc voltage and amperage needs to be calculated as to the conversion factor internal to welder (step down ratio)....

In your case you 200 amp output requiring 40 amp input (at 240VAC) would suggest you need a generator capable of a minimum of 9600 watts... IF you include the 50% factor you would want a generator capable of about 14400Watt

240(v) x 40(a) = 9600(w) (less 50% factor)

These are input values BUT everything changes when you adjust amperage (for electrode) up or down....

How ever if you are only welding at 100 amps you draw would be less (about 1/2 max draw) or about 4800 watt... So you would want a generator capable of about 7200 Watts (including the about 50% over wattage reserve factor)...

Hope I have not confused you more...

Dale

no you did not confuse me more, you helped clear up some stuff. I contacted northerntools asking for a graph/info on the power requirements at different amp ranges but they still have not provided the info and I doubt they will. I did the same calculations as you did but was not 100% sure on my math so I figured I would seek input.

 

[Jeepnford]

I was pondering this at one time, the only conclusion I came up with is if I wanted to run even my inverter welder at max amps I would need about a 10K generator. For some reason you go over 8 KW on a generator the price increases to the point you might as well buy a welder/generator.