2 Acs on 5500 Onan 50 Amp Service

[325BH]

For those suggesting hard-start caps or a Micro-air easy-start:

Those items only affect the start-up. Once the unit has completed its start cycle and is running, those devices no longer play any role in the operation of the air conditioner.

According to the OP, the air conditioner starts... but shuts down after a period of time.

[270S]

Originally Posted by 325BH

For those suggesting hard-start caps or a Micro-air easy-start:

Those items only affect the start-up. Once the unit has completed its start cycle and is running, those devices no longer play any role in the operation of the air conditioner.

According to the OP, the air conditioner starts... but shuts down after a period of time.

The second ac starts (fan runs for 5 seconds or so, drawing apx 2 amps) then the compressor starts. That is when it shuts down. In essence it never starts.

[270S]

Originally Posted by BBQGUY

Go here:
http://www.twinslan.net/~n0nas/manuals/onan/

Download the following manuals for your HGJAB:

983-0101 Operator
983-0201 Parts
983-0501 Service
983-0600 Install

The error codes are in the Operators Manual. Start with the error codes, but I don't think its your generator. It outputs 48 amps. Plenty of power to run both ac's. But you may have other things running that are over drawing the available amps. Like the fridge on VAC, electrical element in the water heater, battery charger, all pull current large amounts of current. It would be a good idea to run the fridge on LP and turn off the electrical element in the water heater.

From your description the issue is the added power load of starting the second AC. Dometic states in there manual a 5.0kW generator is the minimum required to run dual ac's and also list the compressor's Locked Rotor Amps (starting amps) at 70. This current draw last only for an instant and will not trip the RV or generator current breakers, but does briefly overload the generator. This overload is typically not an issue but the voltage drop can trip out the transfer switch.

The best option is to add hard start capacitors which is relativity easy. If the issue continues, then look at the transfer switch.

Thanks for the manuals direct links!
You may have missed one of my posts, I turned off al CBs except ACs - Nothing else on when problem occurs.
Any links to hard start capacitor posts?

[CedarCreekWoody]

Originally Posted by 270S

The second ac starts (fan runs for 5 seconds or so, drawing apx 2 amps) then the compressor starts. That is when it shuts down. In essence it never starts.

That sounds exactly like a hard start issue. The second compressor fails to start.

[270S]

Originally Posted by CedarCreekWoody

That sounds exactly like a hard start issue. The second compressor fails to start.

It only happens when it is warm. When in the 80s or less it does not seem to happen. The Gen can not handle the load if the OAT gets into the 90s.


I have not tried to replicate it on a shore power hook up yet - will soon, but expect everything will be OK. Its a gen problem.

[270S]

Originally Posted by 325BH

For those suggesting hard-start caps or a Micro-air easy-start:

Those items only affect the start-up. Once the unit has completed its start cycle and is running, those devices no longer play any role in the operation of the air conditioner.

According to the OP, the air conditioner starts... but shuts down after a period of time.

FYI The second ac starts (fan runs for 5 seconds or so, drawing apx 2 amps) then the compressor starts. That is when it shuts down. In essence it never starts.

[wrapperman]

Please clarify. Generator shuts down, compressor on the A/C shuts down, the whole A/C shuts down (including the blower fan) or the ATS kicks out.

[270S]

Originally Posted by wrapperman

Please clarify. Generator shuts down, compressor on the A/C shuts down, the whole A/C shuts down (including the blower fan) or the ATS kicks out.

Read prior posts. The second ac unit turns itself off shortly after it starts - only the fan drawing 2 amps starts, then as the compressor engages, the ac turns off.

[wrapperman]

Control board or compressor is going bad.
My first guess is control board.

[Tbonz]

Had same problem
Called Bennie at Progressive Dynamics..He sent a new cpntrol board for ATS. Installed today and both AC inverter and residential fridge ran flawlessly for 45 minutes when i shut generator off. The little board is a pain to replace.

[CedarCreekWoody]

He is having problems with the air conditioner compressor shutting off, not with generator, inverter, etc. He States that above.

[270S]

Originally Posted by CedarCreekWoody

He is having problems with the air conditioner compressor shutting off, not with generator, inverter, etc. He States that above.

That is correct, but the problem is with the generator not being able to handle the 2nd ac during its startup. The Gen drops voltage as the 2nd ac starts and then the 2nd ac does not continue its startup.

[wrapperman]

If it has low voltage then the generator should produce an error code.
Have. You tried to retrieve an error code by pressing the start/stop switch?
It is either the control modular on the generator or control board on the A/C.

[Walter Pigeon]

Originally Posted by 270S

FYI, I am an OEM in the Marine Environment. I checked that all wiring is OK. Each ac unit is on a dedicated circuit and separate feed. See pic.

Where is this breaker panel located ??? We have a 2011 Georgetown 337ds...

[270S]

Originally Posted by Walter Pigeon

Where is this breaker panel located ??? We have a 2011 Georgetown 337ds...

I have a 270 S not a 337ds so it is probably in a different location. My CB panels are in front / under the aft master bed.

[HDsteel]

I have a 17,3250 Cardinal that came geny prep and installed a Onan 5.5KW propane unit in. Long story not done yet, The Precision Circuits Power Control System will not communicate with the LPI generator genie and allow the generator full output. Even if you scroll to gen and the display reads 44 amps it defaults back to 30 amps and turns off the second A/C. Runs both A/C units fine on 50 amp shore power. Your issue sounds identical to mine. Did your unit come equipped from the factory or installed after. I have tried Forrest River and my purchase dealer and have struck out. Also the LPI generator genie seems to have an issue with the hour meter and is being replaced industry wide, maybe this is our problem.

[CHICKDOE]

I went back and reread all the posts. as I understand it seems like all circuit breakers on the rv are off except the two for the a/c's. you can turn either one of the a/c's on by itself and it will run. then we you turn the 2nd a/c on the second one will not start and run. this has been performed reversing the sequence of the a/c's and both sequences perform the same.


i'm ready to buy into a generator problem. it is totally unfortunate that the one generator facility you took it too didn't seem to listen. from what you say you could just perform the two a/c sequences in front of them to show them the problem. why they started crawling under the trailer before they understood the problem is beyond me. the problem is obviously load related.


i just had a problem with an onan 5500 lp generator. by the way it runs the two a/c's just fine. i ended up taking it to an onan service center. i was absolutely favorably impressed! they had two techs that were dedicated to working on their generators. and they knew their stuff. they were able to diagnose the problem while i was there but i had to leave the trailer for a couple of days as they had to order some parts. they replaced a cylinder head and rocked arm and it didn't cost me a penny! if you are anywhere near an onan service center i would tell you to make an appointment and have them look at it. i'm sure there are competent independent repair facilities out there but it appears you didn't find one. stop beating your head against the wall, something is wrong. i would think the odds of both a/c's being bad is pretty low, especially when each will run by itself and each will fail when it is the 2nd a/c being started.

[HDsteel]

Actually the generator will run both units started one at a time for about 5 seconds until the power control flashes 33 amps and turns the last one started off. It is doing its job. The manufacturer says it needs a wire from the hour meter to signal the generator is live and this signal puts to sleep the controller and lets the generator handle the loads. It is rated 44 amps continuous but all gens have a short term rating that is higher for starting current. But with the LPI generator genie and monitor control all functions are wireless. It took us hours to figure this out and program the control for a generator to remote start, stop and display hour meter. By the way my hour meter now reads 17 hours and that value is a telltale sigh is is malfunctioning according to the manufacturer and needs to be replaced by a dealer only or void the warranty. I find it hard to believe I am the only person to install a generator myself.

[270S]

FYI, I am an OEM in the Generator Business. Identical generators running on gas vs gasoline have 20% less power available to run loads.

[CHICKDOE]

Originally Posted by 270S

FYI, I am an OEM in the Generator Business. Identical generators running on gas vs gasoline have 20% less power available to run loads.

I've heard that before. the key word would be identical. I have an onan 5500 lp generator and the specs very clearly state it will output 5500 watts. this is the same output spec as the onan 5500 gasoline model. based upon the quote above you would expect the lp model to output less. but it is right up there equal to the gas model. I had to have the generator serviced by onan recently and the tech doing the repair said he put it on a load tester and he was getting more that 5500 watts. he said the lp model is really a 7000 series gas model that has had the fuel system modified to run on lp. so the 5500 series gas and lp model are not identical generators. he said they do this so they can offer a series of generators using different fuels and all generators in the series will deliver the same rated output of the series.