The 110V AC Magic Chef 3.6 cu. ft. refrigerator
that came with the trailer has not worked out so well. We just replaced it with a 12V DC 4.2 cu. ft. Truckfridge model TF130. The two year old Magic Chef dorm fridge always worked fine on 120v shore power and initially worked fine running off the 600w inverter too but as time went on it got harder and harder to start with battery
power through the inverter. By last month it wouldn't start at all. Even with electric hookups at all the places we camp this means the fridge doesn't work while driving. An all day drive is long enough to have the freezer defrost itself and melt water to run onto the floor.
The Magic Chef manual states specifically not to use it in an RV and my theory is that the trailer hitting bumps caused the motor - compressor unit to wear and gradually require more power to start. That would be no problem when plugged into the normal 1800w 15amp shore power circuit but became a big problem when limited to the 600w max inverter output. It's operating consumption is only 80w, the rule of thumb states starting load should be 5x or 400w but the 600w, 900w for two seconds, inverter can no longer start it.
The Truckfridge is a rebranded Indel B unit made mainly for marine use. It used a high quality Danfoss compressor. Subjectively it is much quieter than the Magic Chef and is much more efficient. It has 17% more capacity yet uses 40% less power. We should be able to manage 3-4 days of off-grid camping.
The new 12v fridge is wider but shorter than the old one so the cabinet frame needed to be cut back and the electrical
panel moved an inch forward to accommodate the greater width. The new unit is 3" shorter so I had room to add a 2" high drawer under the counter, perfect for silverware and cooking utensils.
Here's the fridge space with the Magic Chef removed. The face frame must be cut back flush with the 1/2 plywood cabinet side and the wiring bundle must be rearranged so as to lay as flat as possible against the plywood.
I stripped the outer black insulation from the 30 amp shore power feed to the AC panel and relocated the neutral and ground bus bars against the outside wall so they are behind the new fridge rather than beside it, restricting width.
The lower wires are for the DPDT switch used to connect a pair of outlet boxes and the USB power strip to either inverter output or shore power output. I also added a SPST switch in the +12v line to the fridge so it can be turned off easily without using the thermostat inside the fridge. This wasn't strictly necessary but I wanted the extra convenience.
The fridge needs a level platform to support the feet and needs to have at least an inch between the floor and the bottom of the fridge for air flow to cool the compressor. The supports need to be contoured on the bottom to fit the Snoozy's curved floor. I used 1 1/2 x 1 1/8 wood with an 1/8 deep x 1 wide groove to guide the feet as the fridge is slid into place.
I added another layer of 3/4" oak to the cabinet side and replaced the 1/2" Snoozy panel frame with one 3/4" thick and made a 3/4” frame for the DC switches. This was necessary to move the backs of the circuit breakers, fuses and switch terminals forward to avoid interfering with the side of the fridge.
Inside view of revised wiring.
Fridge installed. Note the trim flange screwed to the cabinet face frame. The feet support the weight and the flange holds the fridge in place. There is also a positive lock on the the door so no more forgetting to latch the old door for travel.
The new fridge left a 3” gap from its top the the underside of the countertop. That left room for a 2" high x 20” wide x 16" deep drawer. Self closing drawer slides (from Lowes) will keep it shut when traveling.