Generator Amperage Question for the smart folks

[pegmikef]

The two Honda eu2000i generators I just received start and run the 11k btu A/C in my M21 just fine, but I want to get all the mileage I can out of the generators. I understand that the TT's Converter uses a certain amount of amperage from the generator (mine says "12 A, 950 watts" so I'm not sure exactly how much). My question is that since the converter is already sucking electricity from the generators, when I switch my refrigerator to 12 volt, am I drawing more electricity from the generators, or is it just using what the converter is already drawing? I would prefer to use 12 volt instead of gas, but not if it is using additional power from the generators (thereby increasing the load). Thanks.

 

[hoefler]

Need more info. If the 950 watts is its draw on the 110 volt side, it is about an 8 amp draw. If you have a 2000 watt generator, that is almost half the output. But this is full output, if every 12 volt appliance is on and the battery is taking a charge. If the 12 amp is the output in 12 volts, I would check to see if the output from the generator is more or less. But the 12 volt outlet on the generator is also part of the total output of the generator, not in addition to the output on the 110 volt side. If you have a load on the 12 volt outlet, the available power for the 110 volt will be less. I don't know how much, but it is part of the total output.

 

[lwmcguir]

Curious to know if you really have a three way fridge? Don't see many of them any more. Most are just gas or 120 volt. They do require 12 volt power as well when on gas.

 

[sparkinson]

The 12V converter will draw more current from the 110V input as load on the 12V output increases. Since there is energy lost in the conversion from 110VAC to 12VDC you will be pulling more load from the generators by running the fridge on 12V than if you ran it directly off 110V. The fan in the 110 to 12V converter is evidence of the loss in the voltage conversion, the energy lost is converted to heat which has to be evacuated from the converter by the fan...

I'm making the assumption here that the three way fridge has equivalent cooling capacity when running on the two sources. If the cooling capacity is lower when running on 12V then the generator load could be equal or less of course even with the losses in the 110 to 12V converter.

 

[pegmikef]

Thanks for the quick response. It looks like I might as well just leave it on 110 as it is only 1.6 Amps. Yes, the frig is really a 3-way. It has an automatic mode which changes based on the available sources with the priority being 110V, 12V, gas. I don't know off hand if it requires 12V when it runs on gas, but my instinct is no, since a 12V source would be detected in the automatic mode and it would never go to gas. I usually just manually select the mode. I run the generators in parallel, so I actually have 4 kw (max load) or like 3.6 kw rated load.

 

[wdk450]

Thanks for the quick response. It looks like I might as well just leave it on 110 as it is only 1.6 Amps. Yes, the frig is really a 3-way. It has an automatic mode which changes based on the available sources with the priority being 110V, 12V, gas. I don't know off hand if it requires 12V when it runs on gas, but my instinct is no, since a 12V source would be detected in the automatic mode and it would never go to gas. I usually just manually select the mode. I run the generators in parallel, so I actually have 4 kw (max load) or like 3.6 kw rated load.

Modern RV refrigerators require 12 volts for the heating logic and gas ignition circuits, even if there is not a 12 volt heater element.

 

[lwmcguir]

If you are operating to save money then the LP is going to be cheaper than buying gasoline for the generator. The small generators like we have for the campers are very inefficient in terms of BTU converted to AMPS. Glad you have a three way fridge. We haven't had one for years but they were really handy back in the day.