3000W Chinese Gensets Info.

my 'convert anything' software says 1 hp = 746 watts

MrWizard's software is correct. Apparently, I either hit the wrong key when I typed 741 watts or was more asleep than I thought. Sorry.

I am unsure of the theory that 1000 watts input is needed to get 746 watts of work - I believe something is missing. But, assuming it is an accurate statement, those numbers would support my 30% loss figure. It has been more than a few years since I actually worked with power loss theories and electric motors. But, my recollection was a power consumption of 746 watts was equal to one horse power - period. Now, that doesn't necessarily mean one full horsepower is available at the motor output shaft. For example, an electric motor can have a bad bearing that diverts much of its power just to overcome internal friction losses. But, even if the motor is wasting this energy trying to overcome the extra resistance, it is still producing 1 horsepower when it is consuming 746 watts - it is just that the energy is expended in an undesirable form. This is what happens with a generator. Energy from the gasoline engine shaft is diverted to forms other than electrical output capacity. (I sure had a lot of Buts, didn't I?)

There is only so much efficiency that one can expect from a generator - unless we have super cooled ceramic bearings and all that NASA type stuff included (which we don't). I often remind my EE students that we can neither create nor destroy energy, we can only convert it.... and losses or undesirable conversions will always be present, which is why we don't have any true perpetual motion machines.

I think MrWizard and I are singing from the same hymnal, it's just that we might be on different verses.

Bottom Line - Don't expect miracles from Chinese generators - or any generator for that matter. You can't get more (or equal) energy out than you put in. 5.5 HP and 3,500 watts output do not belong in the same sentence!