Generator + welder

I hope somebody out there can advise me if it is possible to weld with the 260arc welder and a 6.5 Honda generator I have tried it
but the welder doesn't seem to be burning properly
I know you can weld with a combine 5.5 generator and welder
I am also thinking of buying a small hobby mig for reappearing some sheep gate because the piping is to light for the arc welder I was hoping that the mig, will work on the generator as well

If its an old copper wound lump then no chance, my inverter pulls the 5.5kva when you crank it up, you should be ok with a hobby mig though.

the Welder is only two years old
when working it with the generator it's like you have a current turndown to low and just freezes the Rod

You'd need twice the Kva to run a 260amp welder from. A small hobby MIG will need 5Kva +
weldequip

Do you need some sort of smoothing device/voltage protection? heard roumers you cant run welders straight off a genny

MigTig said:

Do you need some sort of smoothing device/voltage protection? heard roumers you cant run welders straight off a genny

Click to expand...

Depends on the generator. I have seen posts of people adding flywheels to keep the sudden change in current from bogging the motor.

Most generators have a rotating magnet with a field coil. The magnet excites the field, that builds up. When it reaches the voltage, the field coil limits the magnetic field (usually by a zener diode).

A sudden surge of current from a welder will collapse the field and require it to build back up.

Others use powered field coils. The regulate the voltage by varying the field current. These respond quicker. However, the generator/field acts like a transformer. Spikes coming back from the welder can be induced back to the field and into the electronics.

Usually it is not an issue. Generators are designed for inductive loads. A 110V circular saw will draw 15A startup and cause spikes when shutting down.

I have seen several generator schematics. There seems to be a threshold at about 4KVA. Below that very simple and designed to run small appliances, tools etc. Above 4KVA, they are designed for heavy surge currents.

The one I just sold was 4800KVA and 5500 surge. Should have run my 130A MIG with no problem (15A *110v = 1800W)

You need to consider generators are usually KVA not watts. Put a inductor across the load. It may draw 10A, but in theory it will draw no power. Power oscillates in/out of the load, the net is 0. This is Power Factor, the amount of power being used vs the total going in/out.

Welders have a low power factor (have seen as low as 0.5). The 2x value suggested by weldequip is about right. That would be a minimum, but I would want a bit more to have reserve and not work the gen hard.

There have been posts on other boards about needing a surge supressor. Not a bad idea as extra insurance. Would make sense that surges would confuse the field and cause bad regulation.

Thanks everybody for your help I use the generator for driving shearing machines during the season it drives three without any trouble and they are quarter horsepower
the generator is a pretty cheap one and comes under pressure if you try to boil a jug kettle with it I'm not sure of its output as it was secondhand when I bought it

shenion said:

The one I just sold was 4800KVA and 5500 surge. Should have run my 130A MIG with no problem

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4800KVA should have run your entire town with no problem

jeees surely he means 4800w not kva
Didnt know they made Reactor plants that small now

Yes, should have been 4800VA (not W, that is different).

What's the difference between VA and W, in basic terms?

Connect a pure inductive load to AC and lets say it draws 2 amps at 100V.

That is 200VA.

It will be 0 net watts as the current is 90 degrees out of phase with the voltage. Power will go into the inductor on half the cycle and out for the other half.

Resistive loads will have VA = W as current is in phase with voltage.

This is referred to as power factor, basically the ratio of net power out divided by total power transferred. If 20% of the power is cycling back and forth between the gen and the load, then the load will have a power factor of 0.8.

Generators are spec'ed in VA, volts is set, there is a limit to the number of amps, hence VA ratings instead of watts.

You will see "Power Factor Corrected" as a feature on higher-end PC power supplies and some welders.

hi

hi im new on hear and i thort i woud tag on the end of this thred insted of opening a new. and one sorry about my spelling im dyslexic.

right so i have a clarke 150te mig welder that i want to run at a filde that has no power supliy. after having a look at this thred decyded i should probibly get a 4-5 kva generator but i have just seen this on ebay:

http://cgi.ebay.co.uk/ROBIN-robin-R...3286.c0.m14&_trkparms=66:2|65:7|39:1|240:1318

and just had to kno if it would worke ok?
i hear a lot of people saying somthing about the enitial draw from the welder boginng the generator down but i thort that this might cope better as it is a Diesel

cheers
seb

hello (one dyslexic to another) a big genny should be ok make sure its upto speed before switching on welder The google task bar has a good spell checker on it

madkayaker said:

hello (one dyslexic to another) a big genny should be ok make sure its upto speed before switching on welder The google task bar has a good spell checker on it

Click to expand...

haha i will have to get a google taske bar then!
did u look a the ebay link?
the geny isent really that big about 3kw. but i thort the fact that its a diesel it might cope with the suden draw of power better and might just do me as im on a small budget.

cheers
seb

Hi Seb,
The Robin has a good reputation as a pumping engine so should be OK on a genny. That set is only 3 to 3.5kw so probably won't run your welder at it's maximum setting, but will be ok at lower amps. One of the sparkies will be able to explain more.

that might struggle to be smooth for the welder as the welder will be pulling almost full draw. The fact its a desile engine wont make much difference

okkkkk cool guys. i will put the Robin to one side for now and keep looking. im shur somthing will apear and i might as well get somthign that is up to the job.

cheers
seb

I've got a Honda type 6.5kW gene, the draw from my inverter knocks it out if it isn't warm

You can get "electric start" kits for the honda GX390 engine that come with a 6kg "flywheel", if you could get an engineering shop to "upweight" the flywheel and balance it to about 10kgs then it should provide enough "momentum" to keep the revs up when the initial surge hits...

Problem I found with mine was the built in centrifugal clutch disengages just as you get to about 50mm of weld and the gene cuts out until the clutch re-engages...

you might be able to get a gas kit for that Om. Feed little Om with beans and free welding