MIG off small generator or inverter: ACTUAL Experiences?

[GRW]

Now then, I thought AVR simply stood for Automatic Voltage Regulator. Why the capacitor type might be considered as non-automatic, I’m not sure. Need an explanation please, as I always think automatic control is simply the opposite/alternative to manual control.

You're right as to what AVR stands for. I think the best way to think about is that the AVR is an active electronic system, where the capacitor is more of a passive, reactive method.
A decent AVR maintains the voltage not just regardless of the load applied (within the capabilities of the machine), but also over quite a wide speed/frequency variation, where the capacitor alternators voltage output rises with more speed, and drops with a falling frequency. Also the capacitor machines can gain volts as a small load is applied, where an AVR set shouldn't vary.
(There's a 3rd type - a transformer winding voltage control that's rarely seen now. Great fir big motor start and impact loads, but like capacitors, the regulation is rather crude and not tight like a good AVR system).
Often, lots of electrical loads are very tolerant of voltage variation - so you can get away with a lot - but electronics are often the most demanding/particular.

 

[henry Kadzielski]

(There's a 3rd type - a transformer winding voltage control that's rarely seen now. Great fir big motor start and impact loads, but like capacitors, the regulation is rather crude and not tight like a good AVR system).

Not quite correct. Meccalte alternators have 'compound' wound alternators. Like you mentioned above good for starting big loads. In fact the compound wound voltage regulation has the highest overload / starting current 400%. There is also a derivative of that again, which is the compound and AVR together. The compound on it's own also has excitation regulation which you can adjust with changing the tapping on the diode board to get the correct voltage regardless of load. I like them and use them where possible as there is no electronics to fail. Just my two cents!

 

[GRW]

Not quite correct. Meccalte alternators have 'compound' wound alternators. Like you mentioned above good for starting big loads. In fact the compound wound voltage regulation has the highest overload / starting current 400%. There is also a derivative of that again, which is the compound and AVR together. The compound on it's own also has excitation regulation which you can adjust with changing the tapping on the diode board to get the correct voltage regardless of load. I like them and use them where possible as there is no electronics to fail. Just my two cents!

Only time I've seen those used in recent years, was on special-build gensets, built to go with mobile X-Ray machines.
Most MeccAlte 4-pole stuff is auxiliary winding + AVR, similar principle to the Leroy AREP system yes (300% overload)?
(Place I work has been a MeccAlte Agent for somewhere around 40-years. We used to use a lot of their transformer controlled 2-pole, 2-brg though (adjust air-gap to alter voltage) on PTO gens.

 

[henry Kadzielski]

@GRW. That's the ones, quite fiddly to setup but quite reliable. I use them on fishing boats. But to be quite honest the AVR's don't give much trouble either.

 

[GRW]

My old Stamford armature genny has current transformers for AVR.. Works good enough for me, although it does need a high initial load to work at its best, I am told.

The transformer Meccalte ones would sit at say 220-ish volts Ph-N off load - but apply any load and they'd instantly gain 10-15v. Seems they needed a bit of load to excite properly. After that, pretty stable throughout their load range.

 

[finyuk2005]

If the welder has a good manual, it will tell you not to use an inverter welder on a small generator.

I just looked at that generator quoted by the OP.

Haha - it has a petrol engine rated at maximum 5.5HP. The spec needs reading very carefully - more carefully than the OP did, I’m afraid.

thats a 2kw continuous genny at most!

 

[finyuk2005]

But nowhere does it say that. I wonder why? 6kW and 60kVA) claimed in the same line

15l fuel tank which will last 11 hours of continuous running? That’s about 150kWh of energy from the fuel, so 13 1/2kWh consumed each hour. I doubt the petrl engine is (much, if any) more than 25% efficient, so our available fuel energy is already down to less than 3 1/2kW, Then there is the generator efficiency - let’s say 85%. That would now indicate a maximum output of 2.9kW.

I have been ‘generous’ with my calculations - on the side of the seller, so another 10-20% less could easily be expected.

I would guess maybe 2.2kW, at best.

If these are, indeed, the true specifications, the false claims are atrocious - but unless one actually reads more than the opening claim, expect to get caught, hook, line and sinker by these carp sellers.

Wonder how many of these generators were bought, before the maker changed the name? Made a killing and disappeared. Oh no. They are still at it, still fleecing the unwary and poorly informed!!

i just sold 2 small gennys, one genuine honda engined, the other a copy, both 5.5hp, that one said 2.2kw max, 2kw continuous,
the honda i think said 2.5kw max and 2kw continuous

 

[chris y]

On car panels or 3mm to 2mm?

Car work, lots of it, including chassis, up to 2mm I'd say.

 

[Justme]

15l fuel tank which will last 11 hours of continuous running? That’s about 150kWh of energy from the fuel,

Thats well out.
It might be the total energy stored (not checked) but the electrical output for most mid sized gennies is about 360gm diesel per kWh produced. So more like 40kwh produced if at about 80% loading which seems to be the sweet spot.

 

[Justme]

Car work, lots of it, including chassis, up to 2mm I'd say.

so sub 100amps aprox.

 

[GRW]

Nice easy rule of thumb for gensets - is every 4kva of load needs approx. 1 litre per hour.

I've seen loads of "back of a van" Chinesium petrol gensets with 6.5kva stickers.... when the engine states its 6.5hp - meaning at best it's giving a little over 3kva and 2.5kw, NOT 6.5kva, 5.2kw (which you'll maybe just about get from a good 13hp engine). Bull*****.

You don't need to be Einstein to work out that if there's a claim for 11L to last 15 hours.... that it can't be given more than 3kva or so at that fuel use rate.

 

[Justme]

You didn’t actually read what I wrote? Try again.

Doh,
I will do ten lines as punishment
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard
must read the entire line before putting fingers to keyboard

Hey why dint we have this when I was a kid getting lines would have been easy.

 

[nikos]

Nice easy rule of thumb for gensets - is every 4kva of load needs approx. 1 litre per hour.

I've seen loads of "back of a van" Chinesium petrol gensets with 6.5kva stickers.... when the engine states its 6.5hp - meaning at best it's giving a little over 3kva and 2.5kw, NOT 6.5kva, 5.2kw (which you'll maybe just about get from a good 13hp engine). Bull*****.

You don't need to be Einstein to work out that if there's a claim for 11L to last 15 hours.... that it can't be given more than 3kva or so at that fuel use rate.

My 2c on this,
I've burned up a very expensive inverter welder with these "Chinesium petrol gensets with 6.5kva stickers"....
Good for tacking, but when I set at 110 A, the thing choked, then hunted all the while the display on the welder was flashing.
Managed to cook the IBGT's.
On inspection, when the gen voltage gets too low, you lose the 12VDC control voltage, thus the PWM, and the outputs stay either switched on or off, and if on continuous they cook.

Never had a prob with a real 2cyl diesel 6KVA gen, with AVR at the max of the inverter.

Use a disposable inverter if you will use those gens...

nick

 

[winchman]

We just bought an engine driven welder did the job then sold it on

 

[Bornfree]

(There's a 3rd type - a transformer winding voltage control that's rarely seen now. Great fir big motor start and impact loads, but like capacitors, the regulation is rather crude and not tight like a good AVR system).

I bought a non working lighting tower (with a running kubota engine) and this had transformer regulation. The transformer was the problem it was open circuit it cost as much to get it rewound as I paid for the whole thing. I rang the company that made the alternator (genco) and they had stopped making them.

 

[GRW]

I bought a non working lighting tower (with a running kubota engine) and this had transformer regulation. The transformer was the problem it was open circuit it cost as much to get it rewound as I paid for the whole thing. I rang the company that made the alternator (genco) and they had stopped making them.

Genco aren't a very big Mfr. You don't see much of their stuff (though it was alright).
If you still have it - I can get you an SAE coupling chart so you can confirm the SAE of the rotor disc and the housing - and you could fit a complete alternator from another Mfr (e.g. MeccAlte).

 

[Bornfree]

Genco aren't a very big Mfr. You don't see much of their stuff (though it was alright).
If you still have it - I can get you an SAE coupling chart so you can confirm the SAE of the rotor disc and the housing - and you could fit a complete alternator from another Mfr (e.g. MeccAlte).

Its working now I had the transformer re-wound cost me £200. Genco have finished now when I rang them it was their last week of trading. Very helpful chap in the technical department I gave him the serial number and he told me the wire size and number of turns on the transformer.

 

[GRW]

Its working now I had the transformer re-wound cost me £200. Genco have finished now when I rang them it was their last week of trading. Very helpful chap in the technical department I gave him the serial number and he told me the wire size and number of turns on the transformer.

Didn't realise Genco had wound up. Never had much to do with them, but it's always a shame when another small UK Mfr bites the dust amongst globalised mass-produced competition.