davezawadi (David Stone):

Interesting, because you have answered your own query. These are permanent magnet alternators and probably on very small machines with oversized engines. A short circuit on a conventional (synchronous) alternator will remove the voltage from the AVR (which is powered from the output terminals in most designs), thus removing most of the magnetic field from the rotor. This is a deliberate safety feature to prevent winding damage and mechanical failure. All the other details there suggest that these machines are intended to live a hard life outside, The data missing is how the voltage control works, although there could be some clue from the pilot-excited phrase suggesting that the permanent magnets only give some of the rotor field, the rest being from an AVR. The superior waveform claim is curious too, the rotor design normally is modified to give excellent waveforms from the machines I have seen, often a very small harmonic content with a resistive load. Bad loads can of course change this, but this is not really a function of the alternator. Please post the spec or a link for the data you are quoting, I would like to see exactly what we are discussing.

Well, don't think its answered for certain. I mean I don't know what the output voltage will be at those 300% amps is. In theory lower voltage means less current through a given impedance, so resistance or reactance from the conductors could limit current below 300%. I don't know for sure.



Here is the PDF:

http://resources.kohler.com/power/kohler/industrial/pdf/g5620.pdf



Here is site listing:

https://kohlerpower.com/en/generators/industrial/product/400reozjc

davezawadi (David Stone):

Interesting, because you have answered your own query. These are permanent magnet alternators and probably on very small machines with oversized engines. A short circuit on a conventional (synchronous) alternator will remove the voltage from the AVR (which is powered from the output terminals in most designs), thus removing most of the magnetic field from the rotor. This is a deliberate safety feature to prevent winding damage and mechanical failure. All the other details there suggest that these machines are intended to live a hard life outside, The data missing is how the voltage control works, although there could be some clue from the pilot-excited phrase suggesting that the permanent magnets only give some of the rotor field, the rest being from an AVR. The superior waveform claim is curious too, the rotor design normally is modified to give excellent waveforms from the machines I have seen, often a very small harmonic content with a resistive load. Bad loads can of course change this, but this is not really a function of the alternator. Please post the spec or a link for the data you are quoting, I would like to see exactly what we are discussing.

Well, don't think its answered for certain. I mean I don't know what the output voltage will be at those 300% amps is. In theory lower voltage means less current through a given impedance, so resistance or reactance from the conductors could limit current below 300%. I don't know for sure.



Here is the PDF:

http://resources.kohler.com/power/kohler/industrial/pdf/g5620.pdf



Here is site listing:

https://kohlerpower.com/en/generators/industrial/product/400reozjc