Welding from 6 kva generator ?

[sardine]

I've got a 6 kva Diesel generator repaired and running and hoped to run a small inverter with 2.5 electrodes with it but it's bogged right down at 40 amps, it's useless. It has a Yanmar L100 knock off engine in it.

Is this too low power to run even a 2.5 or is the geny faulty?

Had a look online and Yanmar L100's run up to 180 amp welder generators.

 

[the snooper]

I had one, same engine, brand new alternator and like you couldn't weld with it, could it be the cheap engines not producing enough hp to cope ?

 

[Barking Mat]

Maybe be slight overkill, but spotted this earlier, thought it was very cheap.

Definitely do the job. £400 !!!

70KVA GENERATOR PERKINS ENGINE | Home and Workshop Machinery

www.homeandworkshop.co.uk

 

[GRW]

I've got a 6 kva Diesel generator repaired and running and hoped to run a small inverter with 2.5 electrodes with it but it's bogged right down at 40 amps, it's useless. It has a Yanmar L100 knock off engine in it.

Is this too low power to run even a 2.5 or is the geny faulty?

Had a look online and Yanmar L100's run up to 180 amp welder generators.

The proper Yanmar L100 is only rated at 10hp when fit. I'd not be the least shocked to find the knock-off doesn't get close to the real thing.
Even the proper one at 10Hp is rated at an absolute peak (that it can't sustain for long) at 6kva, but only 4.8KW. In reality it's realistic usable maybe 5kva, 4Kw.

A 13hp Honda GX390 petrol genny (peak 6.5kva, 5.2kw) - used to just about cope with a 180A Arc Welder.... but even then full power from the welder is a very big ask - so I'd guess a Yanmar might do maybe 140A.

If your Yanmar Knock-off is struggling at 40A - then that says somethings not right - and its not making even half the power it should.
Is it set up off load at 52-53Hz (about 3,170rpm)? It'll need to be set around there to work properly.
Also, the throttle lever needs to be all the way across to the adjustable stop (set the stop to run the set offload at 52-53 Hz, and the Governor should then compensate for jncreasing load).

If you've done all that and it's still gutless, then it's a bigger issue (fuel or mechanical).

(Note Yanmar also did an L70 model, which is only 7hp and a genny rated peak at 4kva, 3.2kw)

 

[addjunkie]

Mine will run a 3.2 at 120 amps. Its a hyundai thing

 

[Prajna]

My Kama has an L100 and would also run 3.2 at 120A. Struggles a little when it strikes up but is then fine. It's broke atm but I hope to have it running again when I get a hand to move it. Meanwhile I'm using a 7hp petrol genny and even that will run 2mm rods at 55A. I am using a clever Esab Caddy Arc inverter though which is very tolerant of genny power and long extensions.

 

[sardine]

My conclusion is that the bogging down is definitely not right, it's been set up correctly off load at around 3100 rpm / 52 ha with a tacho and hz meter, and the AVR adjusted to 240 v. I tested the windings and they were supposed to be around 5 v but were all low at around 2 v, maybe this is an issue ?

I know the air filter is clean, theres no restriction in the exhaust, I could try a new fuel filter, getting to the governor weights is out of the question.

 

[Munkul]

What about other electrical load? Say, a 2.2kw fan heater, or a big kettle, and/or multiple of - something that you know will pull a bit of resistive load?

 

[the snooper]

My conclusion is that the bogging down is definitely not right, it's been set up correctly off load at around 3100 rpm / 52 ha with a tacho and hz meter, and the AVR adjusted to 240 v. I tested the windings and they were supposed to be around 5 v but were all low at around 2 v, maybe this is an issue ?

I know the air filter is clean, theres no restriction in the exhaust, I could try a new fuel filter, getting to the governor weights is out of the question.

3100 rpm gives you a mains frequency of 51.66 hz, I always set them up for frequency as its more important to certain electronic items then the exact voltage, the governor should keep it steady if its working right

 

[sardine]

I've got a 3 kw immersion element, is that suitable ?

I've also got a grill unit from a catering van, I'll dig it out and see what the specs are .

 

[Dave-sparks]

I've got a 3 kw immersion element, is that suitable ?

I've also got a grill unit from a catering van, I'll dig it out and see what the specs are .

Yes a 3kw immersion will be fine as a test load as long as it is in enough water to stop it overheating as soon as it is connected.

 

[dobbslc]

See below on how to safely connect up an immersion heater element...

 

[sardine]

I stuck a 3 kw immersion on it via a meter and got these results..

Off load 239 v, 53 hz

On load 214 v, 39 hz, 2378 w

Engine was working very hard, feels to me like it was working way too hard for that load.

Checked the fuel filter is not blocked and checked the air intake, can't be either of those.

 

[GRW]

I stuck a 3 kw immersion on it via a meter and got these results..

Off load 239 v, 53 hz

On load 214 v, 39 hz, 2378 w

Engine was working very hard, feels to me like it was working way too hard for that load.

Checked the fuel filter is not blocked and checked the air intake, can't be either of those.

Bottom line? The Chinese knock-off might look like a Yanmar L10, but doesn't make anything like the power of one.
At a sub-3kw load, a 6kva set should comfortably hold 50hz from a 53hz base

 

[sardine]

It's been sat idle for a year but I'm Sure I welded off it before, Just put a new AVR in it is the only thing that has changed.

I don't think that drop in power is normal even for a Chinese horror generator.

 

[Justme]

I have had a few L100 powered generators.
They last about 2-4k hours dep on how you treat them.
The clones last 1500-2500 hours (but are much less than half the price) again dep on how you treat them.
Once fitted when new they worked just as well as the L100 needing no reduction in load demand from my inverter charger or pass through power. As they age they do droop faster than the L100.

 

[sardine]

I had another couple of hours struggle session with it, multiple swear words and and found a load of mouse nest crud in the engine air intake passage built into the enclosure , part of which I had to rip off to get access and I checked the fuel cut off solenoid, one of these things has bought the generator back to full power and it's no longer bogging down burning a 2.5 or a 3.2.

Fixed it but I'm not sure how.

I was right it can power a welder for intermittent use.

 

[sardine]

No idea how the Chinese make these things because when you need to get the enclosure off for access none of the bolts line up with the holes ever again.

I hate this thing, even if it was free.

 

[Barking Mat]

We've a couple of Cummins Onan gennies at work, 15kva 3ph, PITA to work on, but well assembled, not necessarily well thought out, but then at €15k each they should be.

 

[the snooper]

No idea how the Chinese make these things because when you need to get the enclosure off for access none of the bolts line up with the holes ever again.

I hate this thing, even if it was free.
View attachment 350045

Had one almost the same, they do line up the trick is, don't tighten any bolts until they're all in