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Generator can only run AC with everything else off

sato4000
Explorer
Explorer
I've have a durostar 4400 peak 3500 watt generator. It runs everything but the AC fine without any issues. To power the AC however I have to turn all of the other breakers off except for the main and the AC otherwise the breaker on the generator will flip. Is this normal? The AC is a roof mounted dometic in a coachmen freedom express toy hauler. Does this mean with everything off except for the AC the AC is pulling close to 3500 watts continious? When i got the trailer brand new I had issues with the water pump. Come to find out they had wired it backwards at the factory and burned out the motor. I'm not an electrician but just wondering if something else could be wired wrong or something to have it drain that much power.
31 REPLIES 31

AO_hitech
Explorer
Explorer
When the compressor for the AC starts it will draw easily 3 times the running current. Nothing else can be on then. If your natteries are low hour converter will draw a lot to charge the battery. Make sure the fridge is on propane.

Glad you have figured out how to get it started. You want the cold on high. It makes no difference on startup, but yoi don't want the compressor to stop ( the fan keeps running). Because, if it stops it has to start again. And that means the large current draw again.

sato4000
Explorer
Explorer
UPDATE:

So I think i've figured out the issue now. I have to start the AC by first turning all the breakers off but AC. Then I can turn the fan on the ac on and then slowly turn the fan up to high. I can then turn the AC on with the cold set to medium and AC on medium. After all this I can slowly turn all the breakers on but the converter and fridge. At this point I tried turning the AC on high but it died. Started the same process over waited a long time then I was able to turn all the breakers on in the trailer. I'm not sure why I have to go through all this but it seems this is the only way to get everything on together. If I have AC on low and cold set to medium I can turn everything on right away.

sato4000
Explorer
Explorer
So I went and checked it and switching it to 120\240 30amp doesn't work any different. What I did notice was when the battery was drained it doesn't really work at all with the AC on. Does this mean I have to turn the converter off. There isn't a breaker for it. I'm not sure how to do that.

AO_hitech
Explorer
Explorer
It depends on how your RV works. I've never seen an RV with 50 amp service, so I am not familiar with how they work exactly. However, if you can adapt the twist lock to a 120 volt, 30 amp connection and connect that to your RV then it should work. This is assuming you have 50 amp service, which typically is 240 volt, 50 amp. If you only have 30 amp service then you would only use it in 120 volt mode anyway.

sato4000
Explorer
Explorer
AO_hitech wrote:
I found the owners manual for your generator. Based on the wiring diagram it looks like each "hot leg" when used with 240 volts is protected by a 13.5 amp breaker. That will limit each to that. Your AC is only a 120 volt appliance, so it is only using a single "leg". Therefore, you can only use 13.5 amps. If you can connect with a 120 volt connection instead that would likely solve the problem.


AO_hitech, thanks for checking out the manual. I am not too familiar with wiring diagrams so I would have never seen that. Now that you point it out I can see the two 13.5 amp breakers but are you saying plug into the 4 prong but flip the switch from 240 back to 120 and that should work?

AO_hitech
Explorer
Explorer
BTW, you can find the manual here:
http://www.absolutegenerators.com/images/manuals/Duro%20Max%20Generators%20DS4400-DS4400E%20Manual.p...

And yes, it can only handle a max of 27 (13.5 x 2) amps, not the 30 amps claimed.

RoyB
Explorer II
Explorer II
AO HITECH Thanks for finding the correct manual... I was just showing an example on how easy we can get snookered into the generator specs.. That was the only generator I had a PDF on to paste some specs from it...

Here You are sitting there with a generator with 5000WATTS stamped on the outside of it and it won't run a 13,500 BTU air conditioner if you have the bathroom lights on...

You know the sales folks won't be able to tell you all about it... Just got to do some research before you shell a ton of money...

Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS

paulm999
Explorer
Explorer
It's not unusual for any circuit breaker to become 'weak' and trip far less than it's rating. I'd replace the C/B on the genny.

AO_hitech
Explorer
Explorer
I found the owners manual for your generator. Based on the wiring diagram it looks like each "hot leg" when used with 240 volts is protected by a 13.5 amp breaker. That will limit each to that. Your AC is only a 120 volt appliance, so it is only using a single "leg". Therefore, you can only use 13.5 amps. If you can connect with a 120 volt connection instead that would likely solve the problem.

AO_hitech
Explorer
Explorer
sato4000 wrote:
It is only 30 amps when using 240VAC but I am using 240 VAC so that should be ok right?


You are not using the same generator, therefore it may not work the same. See my next post...

sato4000
Explorer
Explorer
RoyB wrote:
It could also mean that the 30AMP connection is only 30AMPs when using 240 VAC. It may only be 15AMPs when using 120VAC. Need to read the book for the fine print maybe...

It may fall under the spec I listed above....


read what (4) says about using 120VAC/240VAC rated power available at the 30AMP connector if you are running 120VAC.


It is only 30 amps when using 240VAC but I am using 240 VAC so that should be ok right?

RoyB
Explorer II
Explorer II
It could also mean that the 30AMP connection is only 30AMPs when using 240 VAC. It may only be 15AMPs when using 120VAC. Need to read the book for the fine print maybe...

It may fall under the spec I listed above....


read what (4) says about using 120VAC/240VAC rated power available at the 30AMP connector if you are running 120VAC.
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS

AO_hitech
Explorer
Explorer
Amazon wrote:
2 to 120-volt 20-amp 3-prong outlet + 1 - 120-volt/240-volt 30-amp twist-lock outlet


The Amazon add claims it has a 30 amp outlet. If the AC runs fine with everything on from a 30 amp shore power connection but not from the generator the problem is in the generator. Could be a bad breaker on the generator, miss-wired, etc. problem with the generator.

jackandh2o
Explorer
Explorer
sato4000, I have a breaker for it in the electric panel.

Ray