We have a new 5kw generator with a 2 cylinder Yanmardieselengine, 2TNB70-HGE that supposedly runs at 1800 rpm. The following are the running load statistics:
1920 rpm at 0 amp load
1914 rpm at 1 amp load
1884 rpm at 10 amp load
1877 rpm at 20 amp load
1843 rpm at 30 amp load
Are these normal? Or, should there be some sort of a governor to keep the rpms steady? As soon as the generator starts, the incandescent and fluorescent ac lights flicker and get progressively worse as the load increases.
Do you have a freq meter? I'd be surprised to see a 5kw driven by a 2cylinder at 1800 rpm.
If it is in fact an 1800 rpm 60hz unit, the speed difference loaded and unloaded seems to be about as good as you're going to get with a small engine.
Generators usually run a little bit faster under no-load, giving a bit higher frequency. But they generally hit their design frequency and rpm when under load, and can dip a bit below that when fully loaded to max.
What output frequency are you measuring at no-load and 20A load? Is this unit capacitor or AVR regulated?
Lights flickering sounds like a frequency issue, which would be rpm related.
In answer to your questions we determined the rpm with a digital rpm meter on the timing pulley. The specs on the motor are 5.96kw at 2000rpm, ranging up to 10.3kw at 3600 rpm. Frequency at no load was 64hz and at 20 amps it was 62hz and at 40 amps it was 60hz. It has a 25uF, Qn 2.3Kvar, Un 550V-50Hz, -25+70C capacitor.