5kva generator enough?

[Thrashsmith]

I have to do the tiniest amount of site welding using my Thermal Arc 175 SE. Prob running it at 70-80 amps using 2.5mm rods. I'm talking approx 2 inches of weld. The generator hire place said a 5kva generator would do it but a welder friend says he needed a 6 in the past as a 4.5 wouldn't do it. Does 5kva sound enough? I've never used a generator before. Cheers

 

[Badger1bear]

Take your welder to the hire place and ask to try it first. I reckon you won’t have a problem

 

[Kent]

There will be a welders supplies place or a hire centre that will hire you a small engine driven - far better.
I use my lorch and hire the battery pack from the dealer for a song with such things

 

[gt6s]

Indeed a petrol driven welder is exactly what you need.

Laurence

 

[HughF]

Woah guys, steady on..... Plenty of boxes of rods burnt this end off a generic Chinese inverter powered by a non avr equipped 5kva 2-stroke generator. Zero issues. Try it and see, I doubt you'll have any problems.

No need to go down the engine driven route for a few inches of weld.

 

[Wildefalcon]

Is it your generator?

It will do the weld, but may not survive.

Not your problem, not your kit.

 

[HughF]

Is it your generator?

It will do the weld, but may not survive.

Not your problem, not your kit.

Umm, why? It will have an output breaker you know....

So much miss-information floating around on the internet, I should have guessed some of it would end up on this thread.

 

[Matrixx]

you shouldn't be able to damage a generator by overloading it has a breaker to protect against high inrush to the (load) and thermal overload, the AVR will protect the alternator, and the engine will have as a minimum low oil pressure and high coolant temp as shutdowns. the only way to damage it is to run it on light load(bore glazing) or not service it properly.

 

[Kent]

Woah guys, steady on..... Plenty of boxes of rods burnt this end off a generic Chinese inverter powered by a non avr equipped 5kva 2-stroke generator. Zero issues. Try it and see, I doubt you'll have any problems.

No need to go down the engine driven route for a few inches of weld.

Err. He doesn't own the genny! Yes too small a genny can damage the welder electronics also.
Some welding plsntscarry shut down protection mine certainly does. It simply keeps switching itself off if the power is poor to save its curcuitry.

 

[8ob]

My 6kva genny and small invertor hate each other. Was listening to them the other day when I was trying to strike up

Welder. Give me all you have genny I am striking up.

Genny. Sod off, I am having a nap.

Welder. I need all of your 6kva right now or you will ruin my start.

Genny. Don’t care , have 3kva just to get you going.

Welder. Get a move on you have destroyed an inch of weld already.

Genny. Oh all right calm down, you can have 4kva because that’s all I can really supply , the other 2kva was sales hype.

Welder. I give up.

Bob

 

[nickk]

Low risk hire cost if it doesn’t work,I’ve run 3.2 rods,several,on a 7 Kva numerous times.

 

[Matrixx]

There are different ratings for generators, basically you can have ones that will handle 100% load continuously, some an 10% overload for 1 hour, and some that can handle 100% but not in one step ( mainly turbo engines), then you have Chinese ones which make up their own ratings!

A welder generator is built for that purpose.

(Note it's kVA Volts & Amps are the primary units)

 

[bletchmonster]

I use gys inverter mma on 5 kva gennie (albeit very heavy duty 5kva) and at 80 amps with the hot start arc set low the gennie barely changes note when you strike up. In fact the site work kettle works it harder than the welder.
As long as its a decent quality generator I'm confident it will be fine.

 

[Turbo]

My TA 160ma will not run on my Chinese 5kva generator!

If it was me I would hire a generator/welder unit. It shouldn't cost very much more to hire than a large generator and will give you the same smooth DC welding current as your TA 175se.

 

[Brad93]

I’ve never had any luck with 5kva generators. Always needed a good 6kva+ to get a decent arc

 

[jerrytug]

Done a bit of site work using a Kemppi 180 invertor MIG, and it was smooth and happy with a Honda 3.5 kva petrol genny. Not at 180, more like 100-ish amps maximum, in short bursts.
I think the quality of the generator, (and a vaguely truthful Kva rating, as said above..) makes a difference.
Surprised to hear talk of such big kva being needed, for 2.5 rods for a few minutes.

 

[Thrashsmith]

Thanks for the replies all. Discovered that the old boy farmer next door has a hefty welder generator I can borrow, I just need to scrape an inch of rat and pigeon poo off it.
I may post a pic or two of it in due course. He's a bit cavalier with equipment so it would be nice to have the reassurance that it doesn't look like something that'll go bang on me.

 

[Bill Edwards]

You should be ok if you end up reverting to plan A.

Yes generators and welders don't always mix that well but a decent inverter welder running a 2.5 rod is going to pull a lot less than a buzzbox with a bigger rod which can lead to problems. I think people who are used to transformer based welders forget this when thinking about generators...

I'd be more concerned with the inverter not liking the gene, though I don't think they go bang all that often on generators, but it's something I always worry about.

 

[dannyp]

The thermal arc is quite forgiving of **** gennys there’s a bit of a knack to getting it going but it works.

I found gennys ether stall or the output breaker trips. Sometimes inverters trigger there low input voltage thing. Diesel gennys allways cArry welders better but I’ve done shed loads off a 7 kw petrol and my 5.5kw Lombardi did loads before the vantage came allong

 

[Kent]

Thanks for the replies all. Discovered that the old boy farmer next door has a hefty welder generator I can borrow, I just need to scrape an inch of rat and pigeon poo off it.
I may post a pic or two of it in due course. He's a bit cavalier with equipment so it would be nice to have the reassurance that it doesn't look like something that'll go bang on me.

The insulation on the leads should be checked over before you start it up. For some reason farmers are very cavalier about insulation on electrics