We have been having problems with our reefer system as long as we have had the boat. It is a Grunert system with a Bitzer compressor
driven via a belt by a 12V DC motor
. The system is water
cooled and drives 2 Crosby holding plates in the freezer
and one in the fridge. The whole package sits in the engine
room sharing space with a nice big Perkins
The system works fine at anchor
and under sail but when the engine
room is warm (after a few hours of motoring ) the overpressure switch shuts down the system. Even a few hours after motoring the system still overpressures. Confirmed overpressure as can force the system to run by bypassing the overpressure cutoff for troubleshooting.
pump works to capacity and was replaced anyway. The condenser coil is substantial and was just cleaned. The compressor
is new. The engine room has a blower that always is run with the engine. The engine is not overheating
. Refigerent level is good (checked by two different techs).
We have had four (!) different companies look at the system with no joy so seeking suggestions from the forum.
Suggestions so far but not yet implemented:
- wire in a switch so that under power the water cooling
could be run independently prior to running the compressor. This would only cool the refigerant in the condenser though.
- suggested that the original shop in Seattle
may have mis adjusted the tx valves or the superheat. The Seattle
shop switched the system from R12 to 401A. With the problems we were having we switched back to R12 when we put the new compressor in at San Diego
in case the the 401A was the problem with the overpressuring.
- insulating the refrigerant lines in the engine room.
Thoughts ! Suggestions ?
Intention is a South Pacific
crossing next month so no time to rip the old system out and install something new (not to mention the cost !).