Turned on roof A/C and generator shut off

[Jason Worman]

Hi All,

A strange thing happened the other day; I turned on generator and let it run a good 10 minutes and then turned on one rooftop A/C. When in "fan only" mode ran fine, when I turned selector knob to "low cool", a/c stopped working and  generator shut off. No breakers tripped or anything. Let everything sit 15 minutes, repeated previous action and A/C ran fine for the rest of the day while on generator power. Any thoughts?

Jason

[Fred Brooks]

Hi Jason,
  Sounds like you know what you are doing. A couple of things could cause the Gen to shut down. If the "start capacitor" for the air conditioner compressor was discharged, The compressor would draw excessive amperage and overload the Gen just enough to shut it down to protect itself. Once the capacitor recharges itself the problem goes away. Another cause is if you short cycle the air conditioner. If you start to cool then go to fan and then quickly back to cool that will lock up the compressor momentarily. If it does it again, perform an amp draw test on the air conditioner.
Hope this helps, Fred