Gen set won't support 2 air conditioners

[craig ketels]

HI All,

I've got a 2015 coach with 50 amp service. Onan 5500 gen set will only support mt 2 AC's for about 20 min then they shut down, I hear the gen surging. I can shut the AC's off for a couple of minutes and the the gen will support one with no problem. I was told that this gen set would support the 2 AC load,

Opinions??

Thanks Craig

 

[Charlie 5320]

My 5500 onan runs both of my airs with no problem. Was on a trip a couple weeks ago ran both airs all day long with out issue.

 

[TonyDtorch]

you could order 2 new start-up capacitors online and try replacing them.

It's a pretty cheap try ($40 +/- ) takes 10 minutes to do and it may fix them.

 

[craig ketels]

Hi Tony thanks for the response.
What is a start up capacitor? I'm mechanically inclined so install should be easy?
Thanks

 

[AStravelers]

Gas or diesel?  Generator surging, have you changed the fuel filter?  Any error codes on the generator.  Check your operators manual to see how to check the error codes.  Gas generator, did you run the generator every month for at least 30 minutes (1hr is better) under 1/2 load?  If not the carburetor could be gummed up. 

 

[Gary RV_Wizard]

Sounds as though the genset is struggling to sustain a high amp load. Two a/c units is about 2500 watts, but when coupled with other loads the genset is probably running at 3000+, about 55-60% capacity. It may have fuel supply problems (when was the filter last changed?) or be overheating under load.

The Onan gives a code when it shuts down like that, blinking the light on the start switch. The code will give the basic reason and is the basis for further troubleshooting.  Your owner manual tells how to read the code (see Troubleshooting section). If you don't have the Onan manual, download at https://www.electricgeneratorsdirect.com/manuals/RVQG5500_Man.pdf

 

[Mile High]

We could run two 15000 btu ACs on our LP-5500 Onan, however, I did have to swap one of the ACs over to the other buss in the panel to balance the load.  You might ask someone to help you check that.  Also I had to switch the hot water tank to propane, and I think I did the fridge as well.

When on 50A service with 50A going to each buss in the panel, it doesn't make a difference, but the 5500 only puts 30A to each side of the buss (or in some of the 5500s, 20A on one and 30A on the other).