Generator was running two AC now only one or the other not both!

[The Maverick]

Hello:

Hope everyone is well. I have a 1997 30' Airstream Motorhome Land Yacht Class A. The Generator would run the front AC and the aft birth AC. Yesterday, I had them both running from the Generator for 3 hours. I shut the Generator off and when I turned it back on it would run either the front or the Aft but not both. Has me really stumped. It's a 30 ampere load center, shore power original OEM would run front or rear select by a switch in the settee area. At some point someone wired a second "shore power" where you plug the female of a extension cord to a receptacle and the 30 ampere shore power like you would normally and it enables both AC to run at the same time. Shore power seems fine. AC units work fine. The issue is now I can only run one AC at a time from the Generator and I always could run two. Any insight is greatly appreciated I am well versed in electrical and have ampere probes and fluke DVOM. Also, does anyone know where the "Converter" or "Battery Charger" is (BC as referred in the schematic). It's not under the hood as far as I can tell its not under the rear birth bed its no where's to be found......I love this Airstream and will continue to TLC it. Its not a tripped breaker in the load center and the fuse at the Onan 5 kW is good has me perplexed. Its nothing a 5th can't take care of over the weekend Kidding so Kidding..... Thank you! Maverick

[Wazbro]

I'll tell what I'm believe,you might already know this. Your generator has 2 120 volt legs (like US 240 volt) 1 goes to the 30 amp panel the other goes to the second AC. No doubt a PO wired the other cord to the second leg (hopefully properly with a transfer switch). Also I'm pretty sure you need to have the AC switch set to a specific AC to have both running from the generator. So check switch then you need to check connection of the second leg and transfer switch if present.

[NevadaGeo]

What's the amperage the air conditioners are pulling, and the amperage your generator can handle. Perhaps today the air conditioners are extra hungry for some reason. Elevation, temperature, humidity could make a difference.

[The Maverick]

Thank you very much! I will check as stated.

[LilPeanut]

And try turning off all circuit breakers except the 2 ACs. Could be the converter charging batteries creating an overload on one side.

[Gulliver72]

I’m going with WAZBRO. It’s a challenging diagnosis.

[The Maverick]

Originally Posted by NevadaGeo

What's the amperage the air conditioners are pulling, and the amperage your generator can handle. Perhaps today the air conditioners are extra hungry for some reason. Elevation, temperature, humidity could make a difference.

I want to say last time I measured it with a Fluke true RMS AC ampere probe with min max it was 11 amperes running. I am due to check it again. It is so hot in Alabama right now I can barely breath outside 95F heat index 105 F you can drink the air is ridiculous humid. Anywho this is where I want to live that is Huntsville, AL!

[mkcurtiss]

Two a/c plus all other electrical needs on 105 degree day may be the issue…..5000 watts is just barely enuf……if you are at some altitude , that could be pushing u over……try running them on low and see if it will do that?

I know for a fact, that my 3500w will run my camper and 1 a/c, but the amp draw is much bigger on real hot days, and it is doing all it can do to keep up……

[The Maverick]

I dont think its a amperage issue. However, the local Bangston Motors service guru stated that there was a load shed device in a 2004 AS LY. I haven't been able to locate a load shed device. The surge could go above 5 kW I think I have a issue in the wiring and transfer switch. I am in process of getting my head around how it was originally wired, then modified. It's all fun....Otherwise couldn't be happier I paid 5 K for this 3 years ago. Got about 10 K into it. Still ahead in my opinion. Everyones insights much appreciated.

P.S. It will not run both when both are selected to Fan only. There is a FWD and Rear switch it always had to be in FWD for both to run on the generator. There is also a 3 position Levitin switch above the single pole double throw fwd and rear switch. I am unsure if this is stock and not sure what portion of three it should be in. Of course I have tried all combinations so far.

[The Maverick]

When all else fails look at the manual Hey Union rules throw out all directions and manuals upon receipt of new equipment. Kidding. Breaker tripped on Generator. It was an amperage issue must have been start up surge amps. I dont his kits good for AC to suddenly stop and then immediately try to restart them. Dometic tough.

Thanks All!

[rmkrum]

Originally Posted by The Maverick

I want to say last time I measured it with a Fluke true RMS AC ampere probe with min max it was 11 amperes running. I am due to check it again. It is so hot in Alabama right now I can barely breath outside 95F heat index 105 F you can drink the air is ridiculous humid. Anywho this is where I want to live that is Huntsville, AL!

Lived in Huntsville, AL for many years. Still have family there. We saw temps and humidity so bad you had to chew the air to breathe.

Glad we finally got back to Southern California. Last few weeks we hit 80% humidity and over 100 degrees and thought we went back to Huntsville accidentally!

[JohnTF]

5kw generator , 2 AC units , common starting draw is 3,600 watts X 2 = 7,200 watts ----?
2,200 over draw , if they try cycle on at the same time .
Try a garden soaker hose back & forth on roof , turn valve down to just barely trickle water down sides of trailer .
And or get more power some how .