GEN SET WILL NOT START /MAIN POWER OVERLOAD - Kohler 20resa 20kw Home Emergency Backup Generator

problems cam be low fuel flow or most probable overload
It is to be remembered that the started kw out put is not not the continuous rated out put of a gen set so for example a gen set sold as a 3000watt or 3kva has a continuous out put of around 80% of that and if your current draw is at the top end then the engine will be hard pressed to maintain constant frequency which is rpm controlled

Check main motor over load in compressor electrical panel and manually reset overload. Then reset main motor overload on controller. The main motor overload has to be reset manually first.

something else besides the ac is stopping ( overloading) the genset
if it works well during the day, the compressor has to be working so the ac is not the problem
a 4000 watt gen set has a duty cycle load of around 3000 watts full time so any additional power requirement besides the ac will overload it
electric stoves , microwave ovens , hot water elements , anything that consumes power after dark will when combined with the ac will overload and shut down the gen-set

if you have external utility power connected it could be the system controller that is faulty and trying to start the gen set which will come on line only to sense utility power and shut down
that action is shutting of the utility power and so the gen set starts again
if you are not connected to utility power, again it could be the controller that is faulty causing a problem
best have a electrician or gen set repair shop check it out

consider this
what is the wattage of the coffee pot and what is the wattage of the genset
if they are the same then the overload of the gen set has cut in
the gen set has to be at least twice any wattage of what is connected
other than that take it in for a proper diagnosis and quote

talk with an accredited electrician as there will have to be a special relay/ breaker in the fuse board of the house
the problem is that your genset cannot be running when utility power comes back on as it will destroy the genset

the electrician can wire the board so that when utility power is available the gen set can be started but not connected to the house
when the utiltiy power fails the relay switches over to the gen set and allows it to start and power the house
when utiltiy power is restored the relay disconnects the gen set and reconnects to the utiltiy power supply
This is not a job for anyone except a fully qualified electrician

What is missing here is a couple of things, what size generator are we talking? a residential, commercial, what control is on the unit. They all reset in different ways. One sure way is disconnect the battery charger first (VERY IMPORTANT or control board can be damaged) disconnect the negative terminal off the battery. leave off for a minute they re conenct and re energize charger. Fault should clear unless you have done damage due to over load.

is the auto transfer switch rated to handle a 60 kva gen set cus you can use a larger auto switch on a smaller gen set but it don't work the other way cus you'll be burning up wires and contactors and have a fire !

Can you verify the amp draw on the output? This gen should handle 25 amps continuous. I wonder if you actually have a bit more that 9 amps? It would be nice to check the frequency and volts too...A Fluke multi-meter can read these values.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

Check the Ground Fault Indicator circuit breaker for triping, and look for the high limit on generator. Reset the main breaker by triping it full right and then back. Vitally