Running LP/AC fridge on inverter while traveling?

[Bullitt6283]

I have always run the 2-way fridge on propane while traveling. There have been some observations that this is a bit risky.

So, in my usual mode of overthinking everything, I am wondering if I can run the fridge in AC mode with the 1000 watt inverter while driving. It would require a minor bit of rewiring the rat's nest behind the power center. The AC heating element of the fridge pulls about 300 watts. This would equate to about 25 amps on the DC side of the inverter, so the loads look OK since this is a Class C and the wiring is heavy enough and the alternator should (?) be able to keep up.

The inverter has a transfer switch in it, so if I am hooked to shore power or running the generator the fridge would run on AC power directly.

Am I missing something?

[twinboat]

I did it for a while, on my old class C, and it worked fine.

I went a bit further and used a voltage sensing relay to control the 120 input. When I shut down the engine, it switched to gas, so I didn't need to remember to switch the fridge from auto to gas.

[Bullitt6283]

Originally Posted by twinboat

I did it for a while, on my old class C, and it worked fine.

I went a bit further and used a voltage sensing relay to control the 120 input. When I shut down the engine, it switched to gas, so I didn't need to remember to switch the fridge from auto to gas.

Interesting... Can you please provide details of this relay?
.

[aether_one]

Originally Posted by Bullitt6283

I have always run the 2-way fridge on propane while traveling. There have been some observations that this is a bit risky.

What about the risk of pumping gasoline to the engine while running down the road?

[mikeh2obury]

Seems like you could just shut down the inverter while fueling and switch back on afterwards.

[aether_one]

Originally Posted by mikeh2obury

Seems like you could just shut down the inverter while fueling and switch back on afterwards.

Why? There's no open flame when running on 120 VAC.

[Bullitt6283]

Originally Posted by mikeh2obury

Seems like you could just shut down the inverter while fueling and switch back on afterwards.

Originally Posted by tfryman

Why? There's no open flame when running on 120 VAC.

If you have the fridge controls set to automatically fire up the LP burner when the 120VAC is not available (when the inverter turns off) then the spark igniter will be trying to light the burner while you're sitting next to the gas pump. Not an optimal condition.

Leaving the inverter running will drag down the charge on the coach batteries. OK if you have an adequate battery bank.

Or for the short time you're at the fueling station, just shut it all down....


.

[Mudfrog]

Originally Posted by Bullitt6283

If you have the fridge controls set to automatically fire up the LP burner when the 120VAC is not available (when the inverter turns off) then the spark igniter will be trying to light the burner while you're sitting next to the gas pump. Not an optimal condition.

Leaving the inverter running will drag down the charge on the coach batteries. OK if you have an adequate battery bank.

Or for the short time you're at the fueling station, just shut it all down....


.

May be getting a tad bit more complicated but adding a time delay relay might work to cover the refueling shut down. Could have it set to delay killing of the invertor for something like 5 or 10 minutes after the engine is shut down.

Or possibly, maybe have the invertor tied into, via a relay, the accessory mode of the chassis ignition switch. Could kill the engine but leave it in accessory mode for those short stops. It would kill power to the invertor completely when in the off position.

[mikeh2obury]

There is an off button on my fridge. Using that should keep propane from trying to fire up the fridge, but I agree it is easiest just to shut everything down, fuel and then turn it back on.

[450Donn]

I think your over complicating a non issue. Thousands of people have towed millions of miles over all soets of roads with no problem. So why?

[twinboat]

Originally Posted by Bullitt6283

Interesting... Can you please provide details of this relay?
.

I use a Yandina battery combiner to control a 10 amp 120 volt relay with a 12 volt activation coil. Got it on Amazon.

When the combiner sensed 13.3 volts, it sent power to the relay coil, closing the 120 volt contacts.

I built it in a plastic electrical box with a short extension cord that was cut in half.

I plugged the fridge into one end of the cord and the other end of the cord went into the fridge outlet. Inside the box, the ground and neutral passed thru the box and the hot line was switched by the relay.

I tied in the 12 volt for the combiner to the fridge 12 volt positive connection. Then the combiner and relay ground went to the negative fridge 12 volt connector.

It was built with male and female plugs so it could be easily bypassed. Just pull the plugs and plug the fridge back in like normal.

It worked fine but as others have said, it isn't worth the gas it saves. ( I had the combiner, so cost was low for me. )

It also would fire up the gas burner on the fridge anytime I shut the engine down, even in the gas station.

If my fridge spark was going to light off gasoline fumes from the opposite side of my fuel fill, so would the cars starting up, closer to me, on the other side of the pump I'm using.
Automobile engines are not explosion proof and gas station fires are rare.

[aether_one]

Originally Posted by 450Donn

I think your over complicating a non issue. Thousands of people have towed millions of miles over all soets of roads with no problem. So why?

Because of the blown out of context horror stories about the dangers of propane.

Makes you wonder about natural gas vehicles.

[Soppy]

I run mine off my inverter when the engine is running and the battery is above 13 volts. On my fridge I can select AC , LP or auto. I leave it in the AC mode and the fridge will not switch to propane when power is lost. The main reason for using the inverter while traveling was to automatically turn off the fridge if we parked in an off level situation.

[wmiii]

I'm a little confused???
I leave my inverter on most all the time and run the refrigerator off it. And what ever else .
Am I not supposed to do that and run off propane?

Wm