Dometic AC on Generator

[lgray]

Originally Posted by TURBS

15k btu a/c takes closer to 2500 watts to start and about 1800 to run.


2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"
2016 nights camped "14"

Not according to this:

https://www.steadypower.com/pages.php?pageid=133

[TURBS]

Originally Posted by lgray

Not according to this:

https://www.steadypower.com/pages.php?pageid=133

According to my meter I draw 18-19 amps at start up and 15-16 running which is no where near 3500 watts.
Out of 4 dometic a/c units I've never had one draw over 20 amps.

I do see however dometic has recently changed the specs for a 15k to 3500k it used to be 2500k

Possibly because of the brisk air II


2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"
2016 nights camped "14"

[TURBS]

My 13.5k runs almost exactly 1 amp less on start up and running then my 15k


2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"
2016 nights camped "14"

[lgray]

Originally Posted by lgray

A 15,000 btu, AC takes between 3300-3500 at start and 1300-1800W to run.

Jaqspe,

Regardless of the EXACT start wattage, the AC is likely putting a higher load on your generator than your microwave.

[Jagspe]

Thank you for all your help. I have more information now. I put some cleaner in the gas tank that was recommended by Onan with no help. I tried to run the AC again, and this time I noticed a clicking noise coming from behind the fuse panel. It sounds like a turning signal. What can that be? Can that be the issue that I am having?

[TURBS]

Transfer switch?


2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"
2016 nights camped "14"

[Jagspe]

Does the clicking mean something is wrong with it?

[BBQGUY]

Please post the make, model, and serial number of the generator.
If the transfer switch is clicking, then the delay switch on the control board of the transfer switch has been disabled.

[KansasFR3]

Originally Posted by Jagspe

Thank you for all your help. I have more information now. I put some cleaner in the gas tank that was recommended by Onan with no help. I tried to run the AC again, and this time I noticed a clicking noise coming from behind the fuse panel. It sounds like a turning signal. What can that be? Can that be the issue that I am having?

I wonder if your fuel pump isn't going out like I believe mine is (also have an Onan 4kw). I'm taking mine in tomorrow to get it checked out. It behaved similar to yours, at high altitude and hot. I used to hear a ticking sound during priming, but from what I understand, it should be more of a thud sound. Mine will run fine right now and run the AC, but I'm guessing it'll shut down again if I start driving and its 100F out. I also have to prime it 3 times or so before it'll start. Hence I'm leaning towards a bad fuel pump. We'll find out tomorrow and I'll keep you posted.

[Jagspe]

Originally Posted by BBQGUY

Please post the make, model, and serial number of the generator.
If the transfer switch is clicking, then the delay switch on the control board of the transfer switch has been disabled.

It is a Onan RV RV QG 4000.

Model Number: 4KYFA26100L
Serial Number: E120336370

[Jagspe]

Originally Posted by KansasFR3

I wonder if your fuel pump isn't going out like I believe mine is (also have an Onan 4kw). I'm taking mine in tomorrow to get it checked out. It behaved similar to yours, at high altitude and hot. I used to hear a ticking sound during priming, but from what I understand, it should be more of a thud sound. Mine will run fine right now and run the AC, but I'm guessing it'll shut down again if I start driving and its 100F out. I also have to prime it 3 times or so before it'll start. Hence I'm leaning towards a bad fuel pump. We'll find out tomorrow and I'll keep you posted.

I checked the fuel pump. I have no issue with the generator starting and running. It is just when the AC turns on.

[Jagspe]

Originally Posted by BBQGUY

Please post the make, model, and serial number of the generator.
If the transfer switch is clicking, then the delay switch on the control board of the transfer switch has been disabled.

Can I fix this?

[Ziggyb0y]

Mine was doing the same thing. I flipped the breakers for fridge and water heater off and it worked fine with just 1 ac unit on.

[Jagspe]

Originally Posted by Ziggyb0y

Mine was doing the same thing. I flipped the breakers for fridge and water heater off and it worked fine with just 1 ac unit on.

I tried that, doesn't help either. Same pattern. AC turns off, I hear the clicking and then the generator turns off.

[BBQGUY]

You unit is s 2012.
Could be a long list of possibilities.
A 4000 would run 1 AC, fridge just fine.
When it's this hot, it's best to shed all un-needed loads.
Taking it in is a good idea.
If you want the most comprehensive feedback post your wuestion in the onan section of this forum. Antique Engines and Old Iron Tractors on SmokStak

[KansasFR3]

Just got back from taking our Gen into Cummins and they couldn't duplicate the vapor lock issue which I expected. Ours has never failed. I noticed your Genset is behind the drivers seat, and one thing the Cummins tech said was that this is a problem location being right behind the engine and all the heat it produces. If you have a weak fuel pump, it might not be able to keep up. He said they typically put a fuel pump inline back by the fuel tank to help push the fuel to the main pump. And splice the wiring into the original pump. He said the ECU can handle the additional amps. Anyways, just some info if your thinking its a vapor lock or weak fuel pump. I'll be doing this mod though to ours to make sure we don't have an issue in the future.

[Threegaleh]

Originally Posted by Threegaleh

I have had the same problem and a guy who repairs small engines says it's not big enough to run the air. Your post could have been wrote by me it's so similar.

Since I wrote this post I got more info, it seems it will run it but you can't have anything else running and we had our hot water tank on which draws a lot