wolf generator wierd problem

[contessaman]

heres a quick one that somebody might be able to help me with.

wolf 1200watt generator, natuarally out of warranty.
its chinese made 4 stroke unit im sure it sold under lots of different badges.

over the winter it failed under load whilst powering a small oil filled radiator well within its rated wattage.
the engine runs fine. but there is no 240volt or 12vdc output...

..unless, I connect a drill for example, I turn the drill on and it turns very slowly, as it draws current so the generator starts to develop more voltage, it turns faster, takes more current, more voltage etc etc. if I stall the drill with my hand the generator kicks out close to its former 240volts.

the engine rpm is governing and staying roughly constant throughout as it did before the fault so the problem is something electrical.

any ideas? or shall I just chuck it? as there is no voltage under light load its no use for running battery chargers etc on the boat which is my main requirement.

ta in advance

 

[lw395]

Look for one on eBay with a blown up motor?

 

[contessaman]

Look for one on eBay with a blown up motor?

yeah, I guess. on the other hand, waste a day of leave swapping the motor over= a days pay = buy another new cheap chinese generator.

I was going to say why is new stuff so disposable but the answer is in the low price eh?

 

[david_bagshaw]

I think you have almost answered it, the regulation system has failed.

I unfortunately dont know the method used with this make. others frequently use large capacitors, which are prone to failure.

 

[contessaman]

I think you have almost answered it, the regulation system has failed.

I unfortunately dont know the method used with this make. others frequently use large capacitors, which are prone to failure.

did take the back off the generator part. found a large capacitor which I went so far as to test by removing it, 'charging' it up with a 12v battery then measuring the voltage on it with a meter, but thats not really testing it under working conditions. my father reckons its something to do with the excitation side of things, perhaps that it has de -gaussed itself somehow but I have heard of generators unused for years doing that but not failing under load. I guess I have probably burned something out by using it to run a mains heater while I fail miserably to get my eberspacher installation working!

think I'll whack it on ebay for spares. If I had more time i'd rip the 240v generator off the motor and put an old car alternator on it. make a 12v charger...

or maybe not.

 

[david_bagshaw]

If I had more time i'd rip the 240v generator off the motor and put an old car alternator on it. make a 12v charger...

or maybe not.

been there done that, put an alternator on a briggs & strat ex mower engine.

Had to use a manual reostat as the standard regulator would bog the engine down.
care needed when charged........

worked well as when the battery is fully charged, the voltage rises rapidly, raising the stator current. this raises the output, loading the engine further, to the extent it bogs and stalls! (tongue in cheek method, not usable in the real world whenthe batteryis connected to anything)


ps not degauss problem, as you have some output, which would have re established things.

 

[nedmin]

Had similar problem with my Kawasaki Gen.The stator had got a bad connection from one winding to the other.They are just useless crimp joints.It was easily seen.Cut the crimp out and soldered it and did others at same time.The stator comes off the rotor quite easily.Google" Generator Guru",great guy with a mine of info.