Now there’s and interesting topic, one to rivet you to this screen. Interesting for boaties who, this summer enjoy a cool beer on board. And fresh fish, fresh meat, veges and perishables. It was not always like this. We circumnavigated without refrigeration partly out of bloody minded Luddite determination to do so. Part of the Kiss principle, a principle that the Admiral and I are readily abandoning bit by technical bit. The masochistic thing was to be independent of problems plaguing other cruisers.
We now have an Engel 12 volt fridge running a flat plate in a compartment with 5″ of insulation. It is cool. Working on the original installation, in my excited rush to complete the job I ran the physical thermostat sensing wire through the back of my electrical panel without preventing it from contacting live components. Hmmm. I wandered what that stink was one day.
I obtained a very nice unit to install. Top of the range Danfoss. To simplify matters I put the unit inside the compartment. This would avoid complications of bending the sensor pipe and leading it through the insulated wall. Only the 12v sensor wire needed feeding. I was instructed by the expert to locate the sensor low down in the centre back of the fridge. To protect it, I used a plastic water bottle cut to surround the sensor bulb.
Judicial use of cable ties and the strong drink container meant the arrangement was secure from being hit by flying beer cans or cabbages.
The upshot is now the motor only cycles on for minimal periods, and we enjoy life away from the supermarket for weeks at a time.
Ps the bulb senses changes in the temperature much like an ordinary thermometer, by expansion and contraction of the gas inside. The relay unit controls the power flow to the compressor motor.