Originally Posted by aftermath
I don't understand the concept of running the fridge on the inverter. I need some help here. In my trailer I have two dedicated outlets for the inverter, no three of them. One is under the table, one is next to the television and the third is in the bedroom by the television mount there.
If I wanted to run my fridge on the inverter, wouldn't I have to reroute my cord that plugs into an outlet behind the fridge back into the coach and over to one of the three outlets I have?
Just "turning on the inverter" isn't going to power up all the outlets, especially the one the fridge plugs into.
Your inverter sends 120VAC to selected outlets only (as you have outlined above). Running your fridge on electric (thru the inverter) will deplete your batteries quickly, as resistance heating (the AC heating element in your fridge) is the least efficient use of electricity in the coach.
If you needed to run the fridge on 120VAC in your case, you would have to either re-wire the inverter circuits to include the fridge outlet or run an extension cord from the back of the fridge to one of your existing inverter-powered outlets.
As an example of just how inefficient the inverter operated fridge would be, here is an example:
The heating element in your size fridge typically draws around 3 amps running on 120VAC. A direct conversion to DC would them be 30 amps @ 12VDC. Since no inverter is 100% efficient, add 15% to the total for inverter loss and you have an almost 35 amp draw from your batteries.
If you have the stock group 24 batteries in your trailer, you have a total of 160 amp/hours of capacity, of which 50% or 80 amps is useable (without potential damage to your batteries from too deep a draw down).
Do the math and you get just over 2 hours of inverter power for the 120VAC heating element of the fridge. NOT MUCH! And your TV's charge line will not be of much help in adding amp/hours to your battery bank. A properly sized solar array would help, but you would need at least 500 watts of solar panels and a sunny day to replenish 35 amps to the batteries every hour.
USE PROPANE! That's why it is included in your fridge operation system. Also, if you have to turn off the LP when going thru a tunnel, the closed fridge will keep food cold for several hours, as long as the door is not opened.