Welding from a generator ?

[sardine]

I picked up a Honda clone petrol generator with 8000w continuous output specs , would this be a good power source for small scale welding, 3.2 electrodes max from an inverter , small MIG or DC TIG or LIDL plasma cutter ?

If that's going to kill the generator then I will refurbishing it and sell it and buy a proper welder generator.

 

[frank horton]

I use an old Lister D genny 1/2 that size for/with a 160amp buz box welder with no trouble....
been doing it on and off for 20 years....
other's will know better but an inverter will prob be easier on the genny....
for using the whole 3.2 rod, the genny does slow down a bit towards the end.....but after a while the temp trips in the welder anyway....

 

[zzr1200]

I have/use a 5Kva diesel genny for my 140amp inverter welder and also run an Aldi V2 13cfm direct drive for air tools from the genny (not at the same time...), I can't see why it wouldn't run those apart from maybe the mig depending on style/type output capacity, only real thing to do is try it....

 

[Prajna]

It depends very much on the welder. I have an Esab Caddy Arc and it is happy even on a 2.3Kw petrol genny on 2mm rods. Turn the amps up and the genny complains but the welder doesn't seem to mind. Cheaper inverters will suffer when the genny can't keep up but the Esab is designed to run on a genny and long extension cables. An 8Kw diesel genny would be luxury.

 

[addjunkie]

A lot also depends on what type of Voltage regulation the generator has, some are much quicker responding than others. Wheres @GRW when you need him.

 

[sardine]

I use an old Lister D genny 1/2 that size for/with a 160amp buz box welder with no trouble....
been doing it on and off for 20 years....
other's will know better but an inverter will prob be easier on the genny....
for using the whole 3.2 rod, the genny does slow down a bit towards the end.....but after a while the temp trips in the welder anyway....

You sure it's a D ?

They are only 2. 5 hp Max.

 

[sardine]

A lot also depends on what type of Voltage regulation the generator has, some are much quicker responding than others. Wheres @GRW when you need him.

It has AVR.

 

[GRW]

Tricky one.
1. The clones often have Chinese KVA, not real KVA.
2. Are you sure it's 8kw, not 8kva? If it's the latter, there's usually an undisclosed caveat that the8kva is at 110% absolute limit, and also at 0.8pf, so the output in kw is really a flat-chat, limited run at 6.4kW.
3. Chinesium AVR's are notoriously fragile.
4. An AVR can actually be worse on some inverter loads than a "stupid" capacitor 2-pole alternator, especially when the inverter load is a) the only load, and b) more than 40-50% of the genset max output. Its a guess, but I think the dumber basic alternator reacts slower to Harmonic feedback from an inverter, so fluctuates less as a consequence. However there's an element of"Black Magic" here & "suck it & see" as different combinations work when in theory they shouldn't, & vice-versa.
5. "Proper" 4-pole industrial alternators have more mass, 2/3 pitched windings, and invariably cope better with non-linear loads than 2-pole stuff designed to run power tools, so it's not just the rated output to consider.

I know a proper Honda GX390 (13hp @ 3600rpm, so a bit less at 3000) with a European decent 2-pole capacitor alternator, would just about cope with a transformer arc welder of about 160 Amps welding rating....maybe 180A at a push.
Theoretically, an inverter is more efficient, so you should get away with more.... however, all the above come into play - so its a bit of a lottery

P.S. The high frequency switching of an inverter is (I think) responsible for sets with capacitor voltage regulation suffering from rapid ageing & failing of the capacitor. I've seen capacitors fail after only a hundred or so hours in this scenario.
Advice from makers of Inverter/Chargers for off-grid power systems had so much trouble when paired with generators (as they would be) that some (e.g. SMA) went do far as to issue an edict to customers regarding "suitable" generators - in effect this was the genny needed to be at least double the rated output of the inverter, and had to be a 4-pole industrial type machine.