3 phase Chinese diesel genset issue

[Freefall1]

Hi I have a 3 phase Chinese diesel genset I run my mills and hoist off it normally I lent it out and it was used to run a heavy duty plasma cutter , :~ result wasn't good apparently it was running fine the cutter went off along with power from genset , can anyone advise if the avr could be the issue and is there a test ? Genset starts and runs fine just not generating ?

Thanks in advance

[Grahame Collins]

I don't know that the AVR would have a lot to do with it. I would be checking the input volts and amps of the Plasma cutter to calculate what it would draw in watts.

Say for instance the plasma was 415 v x 25 amps that would be 10375 watts. The KVa rating of the gen set needs to be well above this.

I would estimate 12 Kva or more. Note! this is my limited knowledge of it.

Grahame

[Freefall1]

hi Grahame thanks for reply your right plasma cutter was too big ! Seems he fried my generator , I was hoping that it had a breaker or something ? The circuit breaker is intact switches off and on but there is no 3 phase, 240 or 12v coming from generator when running ? Can anyone suggest a way to test unit ? Cheers Freefall

[A Duke]

Hi,
If it had an overload breaker it should not have fried. It could be a failed diode in the 12V DC circuit or a loose connection some where.
Regards

[cba_melbourne]

hi Grahame thanks for reply your right plasma cutter was too big ! Seems he fried my generator , I was hoping that it had a breaker or something ? The circuit breaker is intact switches off and on but there is no 3 phase, 240 or 12v coming from generator when running ? Can anyone suggest a way to test unit ? Cheers Freefall

I had a Chinese 3phase 5KVA silenced diesel generator. Was test running it with a 2.4kW@ heater. After about 45minutes it failed. One of the three stator windings had shorted. If one phase is missing, the regulator shuts the rotor excitation off. It was replaced by a single phase unit under warranty.

Now that does not mean yours has the same problem. But you may have to take it apart a bit to find out. Not too bad if yours is an open frame model. The silenced one needs a LOT of bolts to be removed to get covers off. First thing to check is all connectors. On my second one I had two wires not properly criped to the contact, could just pull out the wires. If yours has been running several hundred hours, check the carbon brushes to the rotor. Do you have a multimerter? Check resistance of the rotor winding, and resistance of the three stator windings. Chech them all also to ground, there must be no continuity to ground. If all is well, you can try to replace the regulator - they can be found on eBay. BTW, you can find wiring diagrams on the net, just needs some fantasy to find the right one for your unit because these generators are all sold under misterious dealer names. They are all very similar though. Be wary about the power rating, some dealers sell them with exaggerated ratings that are not matched by the physical generator size/weight, even if the engine is always the same Yanmar clone. The Chinese can put several generator sizes onto that engine, depending how much the dealer ordering them is prepared to pay. And be careful when troubleshooting, generators can kill.