Originally Posted by Richard Kollmann
I have designed maybe 100 hybrid boat refrigeration systems most of these were engine driven and electric. In the 1980s most hybrid systems with electric systems had added 110 or 220 volt compressors...
I have one of the 1980s hybrid refrigeration systems. The plate says, "Kollmann Marine
Products". There is a single cold plate with two internal coils in the freezer and with spillover to the fridge. The compressor
on the engine will keep the cold plate frozen with an hour of run time per day unless the temperature gets in the upper 90s (F), then two 45 min sessions will do it. We make ice and keep meat frozen. At the dock
we run the 125v compressor
to keep the cold plate frozen. Without the daily swings in temperature, everything in freezer stays rock hard. If the engine driven system were to quit, we could run the 125v system off the inverter
as a short term backup. The refrigeration system is old, but still works. With Richard's advice and his books
we have kept it running without any serious problems. The best thing about the Kollmann system is that all the parts
are standard automotive or refrigeration items and are readily available.