Inverter generator

reggienz, Sep 5, 5:54am
Would some one be able to tell me if a 2KW inverter generator would run a 150 amp arc welder? TIA.
mm12345, Sep 5, 6:19am
A bit close for comfort I'd think. Is the 2KW maximum rating or continuous?
I've got a small 150 amp stick welder, and with using a heavy rod and cranked up it will trip a 10A breaker at times when it's the only thing plugged in on the circuit - so it's capable of drawing over 2.3KW - more than it's supposed to.
I guess a 2KW generator will have an 8A breaker, and if that keeps tripping on you, it's going to be very annoying.
I think you should probably go up a size to a 3KW model.
chas10, Sep 5, 6:21am
Im not an electrician but P=VI so 240V x 150A = 3.6 KW so I would guess not
mm12345, Sep 5, 6:26am
You're not a mathematician either - you've put a decimal point in the wrong place. It would be 36KW - not 3.6.

150A seems to be a pretty standard size for single-phase welders with a standard 10A (max) rated 3 pin plug on them.

The 150A is on the output side of the welder transformer. I think it's usually about 12v on the secondary, so 12v x 150A = 1800W approx. But it's the 230v wattage and current rating of the welding unit which should be marked on a label is what should be being looked at here. Output amps is probably not an accurate rating.
saxman99, Sep 5, 6:33am
Inrush current will be higher than the equipment rating which is why an 8A unit could conceivably trip a 10A breaker under full load.
intrade, Sep 5, 9:53am
depends on what the 150 amps are what voltage level is it based on its ohms law matters volts ohms and amps piramide to calculate and then you need 40% extra for all the losses
tony9, Sep 5, 9:59am
A non inverter generator would likely do it. The rotating mass can stand more bumps, and produce a real sine wave which the welder will appreciate.
sr2, Sep 5, 1:42pm
LOL; you should have stayed awake in those physics classes when you were at school, you're spouting rubbish!
sr2, Sep 5, 2:41pm
Sorry mm12345, ignore that last comment I miss-read your post.

You're spot on with your figures although with 85% power factoring you'd be well over the generators 2Kw rating. That aside there are many people (me included) running welders that require 15 amp supply s off 10 amp domestic circuit breakers.
mm12345, Sep 5, 2:42pm
Edit - saw your next post - no worries mate.

I should have read the label on the wee stick welder I have here - single phase 140 amp Bunnings Ozito, about $99 IIRC.
Output voltage (open) is nominal 48v. Obviously my 12v guess was wrong. My bad.
230v current draw is stated as 14A.
So that's why it trips a 10A breaker sometimes.
The welder also states in bold writing that it's got a 15A supply cord. Hmmm - but it's got a 10A ANZS3112 standard three-pin plug on it.
It probably doesn't meet NZ electrical safety standards with that plug on it - yet unless they've been changed, Bunnings are still selling them like that.
tony9, Sep 5, 3:15pm
Are you sure it is a 10A plug? The 15A one looks that same, just got a slightly bigger earth pin which can frequently be forced into a 10A socket.
saxman99, Sep 5, 3:33pm
. although everything comes with a 10A plug and supply cable, it will carry a bit more if it's reasonable quality. Also I see pretty often these days the circuit breakers on standard home wall outlet circuits are rated 16 or even 20A.
mm12345, Sep 5, 3:43pm
I'm positive it's a 10A plug - yeah I know about the 15A plugs with different earth pin, but this even has "10A" marked on it. I'm 100% sure it's the original moulded lead.

I'm a bit curious about that now. Young learner sparky here who's passed regs says it must be illegal. There are some separate regs for industrial welding installations which get a bit tricky, but IMO this is a standard domestic plug-in appliance, and primary current seems to be 14A.

I'm not worried about safety here at my place, as It's always on a 10A breaker, and with choke set at about mid or lower (where I use it with fine rods), no real worries or inconvenience with it tripping. But it does seem very dodgy from a standards / electrical safety POV.
tony9, Sep 5, 4:29pm
Old retired sparky with industrial experience here. All that you have indicated suggests it is illegal. However do you know how the 10A plug got on there?

I am in Bunnings tomorrow, will have a look at that model. I have seen 15A plugs on other welders there.
two9s, Sep 5, 5:03pm
I've got a 2600 kva gene (not inverter) and trying to run my little buzzbox on 70 amps throws the fuse after about 2 or 3 seconds welding. And it does not like trying to start the arc. I reckon you'll need at least 3.5 kw to do any sort of decent weld.
mm12345, Jul 29, 11:29am
I'm 100% certain it's the original flex and moulded plug. Purchased it perhaps 8 years ago. That's not to say that Bunnings got pinged and have now changed to a 15A plug, but I'd have expected a recall if they are in fact illegal when they were selling them.

Not a bad little light-duty stick welder, copper wound. Kind of crappy handpiece, but mines held together okay - and with a proper mask (not the joke "free one" that they give away with it) I taught myself to do an ok job at basic welding jobs.