Residential fridge on generator

[High Country Duramax]

I’ve been wondering about this for an upcoming trip we'll be on generator. Run the fridge on inverter with generator or no inverter and straight generator? My thought process is that generator would work less on inverter until battery needed charged. What am I missing?

[bikendan]

Originally Posted by High Country Duramax

I’ve been wondering about this for an upcoming trip we'll be on generator. Run the fridge on converter with generator or no converter and straight generator? My thought process is that generator would work less on converter until battery needed charged. What am I missing?

Do you mean INverter, instead of CONverter?

[lcv800]

I run my residential fridge off the inverter (battery drawdown) and then run the generator to re-charge batteries (also being slowly charged while towing).
Rusty

[houstonstroker]

My inverter is a pass through design. On generator power the inverter is not really doing anything.

[Wes Tausend]

Originally Posted by houstonstroker

My inverter is a pass through design. On generator power the inverter is not really doing anything.

Same here.

I believe there is a 2nd transfer switch on the inverter that diverts to outside 110v when it can get it. The 1st transfer switch is of course between the shore power and generator so that when the generator is on, all 110v comes only from it.

Otherwise (no 1st transfer switch) the shore power cord would get 110v anytime the generator ran, or in some cases, the inverter ran, which would be dangerous if it were plugged into camp shore power that had failed and somebody was working on restoring camp power.

The safe end result is that, if the generator is running, all 110v comes from it alone.

Wes

[dalford]

Originally Posted by houstonstroker

My inverter is a pass through design. On generator power the inverter is not really doing anything.

correct, inverter in standby mode but the converter is charging your batteries...

[High Country Duramax]

Thanks for that. After I posted it seemed to not make sense that the inverter would power the fridge when there was another power source. I have a pair of Honda 2200s. I will probably just use one to keep the fridge running during the day and at night use both to run the ac(s). I just installed the micro air soft starts on both and they seem amazing. I ran one ac off one generator for a few hours last weekend while I was doing things inside. I used a short 20 amp drop cord and had most other breakers turned off.

[NavyLCDR]

If you are using an inverter with the generator running you are wasting energy and fuel. Inverters are not 100% efficient so you are wasting energy to feed that inefficiency (mostly heat). And it's actually a double loss due to the inefficiency of the converter which will also be supplying part of the DC bus load.

[High Country Duramax]

Thanks. I’ll run the inverter until the fridge stops and start generator.

[NavyLCDR]

Originally Posted by High Country Duramax

Thanks. I’ll run the inverter until the fridge stops and start generator.

If you have lead acid batteries, you don't want to run them down below 50%. If you run the inverter until the refrigerator stops you are likely to damage your batteries.

[CHICKDOE]

You’re just going to have to experiment and see what works for you.

First, as has been stated the inverter will have a bypass relay (a small transfer switch) that will connect the refrigerator to either shore power if it is available or inverter power drawing from the batteries. This may be built into the inverter or it may be external to the inverter. But if shore power is present the refrigerator will be powered by the shore power. In you case the external generators will be connected to the shore power cord so generator power is synonymous with shore power.

Leave the inverter on. It will supply power from the batteries when shore power is not present. The inverter will have a low voltage shut off limit where it will stop providing power when the battery voltage drops to this voltage limit. This is designed to keep you from entirely depleting the battery. It is impossible to say how long the refrigerator will run on a fully charged battery before it drops down to the low voltage cut off limit and the inverter stops. This depends on how much battery capacity you have and what other loads are being placed on the batteries. You’ll just have to experiment to find out.

As soon as you start the generator(s) they will begin to power the refrigerator and recharge the battery. One of your Honda’s should be able to do this. But also realize that it takes many hours to fully recharge a battery. They initially take a lot of charge but then take an ever decreasing amount the fuller they get. You probably won’t run the generator long enough to fully recharge the battery. So the second day you may be starting to rub the refrigerator via the inverter with a less than fully charged battery.

At this point many people will say to install a shunt based battery monitor. It will help you understand you battery condition and status much better than a voltage meter can. My personal recommendation is the victron smart shunt, about $130.

Have fun! This is a learning experience.