I hate to be the bad guy here, but those numbers displayed from sara’s 12/2, don’t add up.
I’ll start out with this:
If a diesel generator made 20 KW at 1800 rpm. The same engine would made about 50% of that rating at 1,200 rpm, 10 KW. The same engine would make 50% again that rating at 900 rpm, 5 KW. That is pretty consistent in general diesel engine capabilities.
Notice the KW capabilities decline rapidly as the engine approaches idle speed and they are not even operating done to idle speeds as sara’s 12/2.
This rapid decline is because the engines torque curve is not linear like an electric motor and uses much of its capability to overcome internal forces drag, compression, ect. at low speeds. There is little left to produce usable electrical output.
For example, a 12/2 operates at 650 rpm and produces 12 hp, 6 KW. A 10/2 operates at 600 rpm and produces 10 hp, 5 KW. Notice they are the same basic engine and with a reduction of only 50 rpm lost 2 hp, 1 KW.
That is because it is following the same downward power capability as demonstrated in the 1,800 rpm generator above and all engines follow.
Now if the 12/2 engine speed is reduced to about 450 rpm, it would produce about 50% of the 650 rpm rating, 6 hp, 3 KW maximum. If the engine speed is further reduced to half the 650 rpm - 325 rpm, it can only put out about 3 hp, 1.5 KW maximum.
Therefore, my first power estimates were accurate when I said the engine would put out about 3-4 hp and I was given it some.
So when sara if getting 2.5 KW continuous, 5 hp and 3.5 KW, 7 hp blowing black smoke. I don’t think so.
I sorry sara but I”ll say it again, “you are full of it” and your not fooling everyone and I’m all done with you and this subject.
Diesel Guy