Onan KY4 slows down with heavy load doesn't deliver enuf for AC

[larryr]

The Onan service guy slowly added load. When it did 30A, he gave it 40 and it did ok. He suggested that the Air Conditioner probably needed a start capacitor. He did not slowly back down the load.

I'll check inrush on both the rooftop and the "equivalent air compressor", unload the air compressor and see if that makes a difference, This is probably the original AC unit from 1998. It certainly had rust on the case of the compressor and fan motor. I'll consider replacing it if compressor service adds up to a significant portion of replacement cost....

 

[larryr]

The Onan did poorly. First I tested a Husky air compressor that draws 15A.
Onan
inrush 55A
Steady VAC under load 108
Freq was 39
Husky on Shore power was
inrush 78A
Min VAC 107
Running at 14A

The rooftop AC
Inrush 20A
VAC 55
Freq stayed up at 59Hz.

The genny shut down and gave a "needs service" code of 3 rapid blinks.
I think the AC is fine!
The Onan authorized service shop that I took it to, has closed down, as has the Redding Cummins sales and service office.