Kohler 5E generator / A/C problem?

[srad]

Hello,
I have a 2005 320 DA with a Kohler 5E Generator. I have a Cruisair SFX12/1-RMT air conditioning unit.
When I attempt to run the A/C off the generator, the A/C will not start. I can hear the compressor briefly attempt to connect and then cut out.
Switch back to shore power and the A/C unit runs flawlessly.
The generator runs all other electrical items without a problem.
I had seen a while back where another member, wrcrdavi, had a similar problem but I never saw a posted solution.
I've had an A/C tech look at it and he said the A/C is fine, get the generator checked.
Going on three weeks waiting for the Kohler tech. More likely to see Santa first.
So, Might anyone have a idea as to what I might look into to solve this dilemma?
Thanks in advance.

 

[fc3]

Assuming the generator's voltage is okay and doesn't sag too much, I'd say it's the compressor's start cap.

 

[srad]

fc3, thanks for the reply.
I also suspected a start capacitor. So I posed my problem to Dometic. Their reply was that the unit did not have a start capacitor. Instead it uses a start assist part #335055.
They suspect the problem is with the power source.
They A/C tech that looked at the unit also said if the A/C starts and runs on shore power without a problem, look to the generator circuit.

 

[scoflaw]

Then check your voltage output on the genny. More rpm's = more volts

 

[fc3]

You'll need a decent digital voltmeter to test. You need two measurements taken at two different times. With the A/C off and generator running and powering the boat, measure voltage and frequency of the power. "Book" spec for shore power is 117vac @ 60Hz, but around 115-120 is fine. You'll need to check your manual for the exact numbers. I have a Westerbeke, so my numbers are different. If not then you need to check the governor or regulator. Then measure when the A/C is trying to start. If the frequency drops more than a couple Hz, then the governor may not be doing it's job. If the voltage drops below 100, then the regulator isn't doing it's job.

 

[Gary Hill]

My 5E has fault codes. Do you get any fault codes? Also, check that voltage from generator. My AC will not run if voltage is under 105 volts. At least I think its 105 volts.

 

[Jetmart]

You'll need a decent digital voltmeter to test. You need two measurements taken at two different times. With the A/C off and generator running and powering the boat, measure voltage and frequency of the power. "Book" spec for shore power is 117vac @ 60Hz, but around 115-120 is fine. You'll need to check your manual for the exact numbers. I have a Westerbeke, so my numbers are different. If not then you need to check the governor or regulator. Then measure when the A/C is trying to start. If the frequency drops more than a couple Hz, then the governor may not be doing it's job. If the voltage drops below 100, then the regulator isn't doing it's job.

"If not then you need to check the governor or regulator."

What is there to check on the governor? My generator seems to be varying a bit on speed as it gets warm. I am suspecting the governor.

 

[fc3]

Not experienced on that generator, but I know that the engine speed is electronically regulated and throttle body fuel injected. Not having a service manual, I'd first look at the throttle body and clean it up. The air valve might be sticking. EFI compatible "Carb" cleaner might be helpful.

Sorry, I can't really help, but it's unlikely the electronics are all that fouled it. I'd be more inclined to believe the throttle body is gummed up. But since I haven't played with one of those, I can give you specifics. Can't hurt to clean the throttle body, though.

 

[srad]

Had the generator checked today. Short story is that the generator was putting out too much voltage for the Cruisair controller.
Tech said one could adjust the SMX controller for the higher voltage or the generator could be adjusted. He adjusted the generator.
My "guess", he adjusted the voltage lower by decreasing the RPM via a governor adjustment. The governor is a gear driven centrifugal unit with and adjustment screw near the carb.
Anyway, works now. He suggest I might consider reprograming the SMX controller such that it accepts a higher voltage, but that's a project for the future.
Thanks for the replies, Steve

P.S. My Kohler 5E service manual is TP-5986. One can find it online. Useful reference, but one will most likely need the services of a trained tech when problems develop.