I installed gauges in the countertop above the icebox: a thermometer (convenient to have one outside the fridge so you don’t have to open the box to check), a green LED that lights up whenever the compressor is running, a red LED to show faults, and an hourmeter to use in measuring the duty cycle.
Here is the wiring diagram for my system:
Also, here is a pdf for the Danfoss BD50F_compressor.
I did not install the plumbing or the pump for the water-cooled condenser–I’m going to wait to buy that stuff until hotter climates (other projects take priority). Up in the bay area the air-cooled condenser is more than adequate, and more efficient than running the water-cooled condenser anyway.
The whole box is painted with two coats of Primekote and two coats of Perfection.
The icebox has stayed 32-38 for the past three weeks, so it’s working well. We have been having some issues with the compressor short-cycling (coming on for two minutes, going off for three, back on, etc). The situation started to worry me when we started getting the intermittent fault code of three red blinks: indicating “rotor blocked or pressure differential too high”. I speculate that the compressor was trying to turn on again too quickly–before the pressure differential had sufficient time to equalize through the evaporator plate. My research on kollman’s forum and the rparts forum tells me that the short-cycling is a result of too much of the thermostat sensor touching the evaporator plate. I have pulled all but an inch of the sensor tubing off of the plate, coiled up a few inches away from it. It seems to be working better, but I haven’t got a trustworthy data set yet to be sure. Aside from that, the box is totally finished:
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