I have a 13,500 BTU AC on my 5th wheel and a Yamaha 2400 Watt Inverter Generator. I live at 4700 ft elevation and I have been able to run the AC at my home with the generator. This past week I was camping at an elevation of about 6300 ft. It got a little warm one afternoon and we were boon docking so I decided to fire up the generator and recharge the batteries a little and turn on the AC for a while. The AC tripped the overload circuit in the generator twice. I was unable to start the AC with my generator. I had nothing else to speak of on at the time.
My question is, I have seen people asking about generators and others responding with statements such as "I can run a 13,500 BTU AC with my Yamaha 2400 Watt generator at XXXX elevation". From these comments and my experience, it seems that the ACs require more "power" at higher elevations. Is this true? And if so why?
Any info on this subject would be appreciated.
Thanks
If you have a 45 or 50 amp battery charger, it might be using 4-5 amps of power in addition to running the A/c unit. You did say the batteries where low.
One way is to unplug the battery charger while starting the A/C unit and then once it is running, the start up load is gone, then you can plug in the battery charger again. The A/c should be using about 13 amps at 120 volts (around 1,500 watts) but at start up it might draw 2,500 watts for a few seconds. Combined with the 400 watt battery charger load, the generator output voltage probably dropped below 95 volts for a few seconds while the A/C was starting, then the A/C amperge went way up, without it ever starting properly.
The generator horsepower is also reduced at 6,300 feet elevation compared to lower elevations. This just made the amperge problem worse. I think that unpluging the battery charger will solve the problem in the future. Then be sure to set the thermostat to it's lowest setting so the compressor will not start to cycle on and off. When it trys to re-start, the restart wattage will be much higher if it has only been off for 3-5 minutes. By leaving the compressor run all the time, then it will not draw extra amps to re-start itself.
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a Porsche or Country Coach!
I always change out the JET and put in a HIGH ALTU JET any time we camp over 6500 ft. We are now in Co over 8500 ft and with every thing turned off MY 2400 will run my 13.5 AC with little problem.Without changing out JET the 2400 will spit and sputter like crazy. JMO
RET Army , DW Donna , Summer (Furkid) . Class A, 2000 Gulf Stream, DIRECTV, YAMAHA 2400 GEN , TOW 97 Wrangler. Garmin GPS 2720 . "Living Our Dream". NASCAR FAN (20,18,11,29,31) Love CO & NM
I did hear somewhere that adding a capacitor to the AC will allow for easier starts and the ability to run the AC with a lower rated generator like a Honda 2K. I never followed up on it, so I'm not sure if it's even a good solution. Just my .02
A generator can loose close to 50% rated output at high altitudes. Many airconditioners have shortened lives by being run when in brownout conditions. I would recommend getting a voltage meter to plug into one of your 110v AC outlets while using your generator to power the airconditioner. If the voltage drops below normal AC voltages, quit using the airconditioner before you send it to an early grave.
Mark
Mark & Jan "Old age & treachery win over youth & enthusiasm"
2003 Fleetwood Jamboree 29
ALL combustion engines lose power with altitude and with heat, unless they have a turbocharger. The air is thinner, so the engines are starving for air and don't put out the same h.p. The compression *ratio* might be the same, but the actual compression is less. High altitude fuel jets will help keep the fuel to air mixture correct, but they won't keep the h.p. up to what it is at lower elevations.
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, DW Donna 
, Summer (Furkid) 
. Class A, 2000 Gulf Stream, DIRECTV, YAMAHA 2400 GEN 
, TOW 97 Wrangler. Garmin GPS 2720 
