Refrigeration System
The refrigeration is a 12 Volt system with the compressor feeding two holding plates in the freezer. The whole unit was supplied by Flemming Marine with full details in the documentation in a folder in the sail locker.
The unit sits on a purpose built shelf in the Quarter Berth, the left side has a piece of teak removed for the photo and the front has a Plexiglas cover that folds down for service marked "I".
See Galley for external view of the actual fridge freezer. Internally the freezer is around 3 cubic ft and same for the fridge. The fridge space is split into two shelves the top being accessed top down through the galley countertop and the bottom being accessed via a front opening door. We typically put items we rarely use in the bottom fridge as it is less economical to open this door. The fridge is cooled by drawing cold air from the freezer. There is a tiny computer fan operated on a thermostat that turns on and off to suck air when needed. This fan activation breaker is labeled "Refrigeration" on the overflow control panel at the NavStation. The Compressor breaker on the main panel is labeled "DC Refrigeration"
The freezer has a thermostat and it is possible to run the freezer automatically, however we never did as I like control over when such a large current draw should take place. We typically run the freezer for one hour in the morning and one hour in the evening. This is enough to maintain temperature, you will need more if putting un-frozen items in the freezer or warm beer in the fridge. Plus we leave it on when ever the engine is running. This past trip we hit a record temperature of minus 24celcius (we had quite a bit of motoring) however we normally keep it at around -6. The current draw is around 40Amps per hour for compressor and cooling water pump and fan, higher on startup.
The unit sits on a purpose built shelf in the Quarter Berth, the left side has a piece of teak removed for the photo and the front has a Plexiglas cover that folds down for service marked "I".
See Galley for external view of the actual fridge freezer. Internally the freezer is around 3 cubic ft and same for the fridge. The fridge space is split into two shelves the top being accessed top down through the galley countertop and the bottom being accessed via a front opening door. We typically put items we rarely use in the bottom fridge as it is less economical to open this door. The fridge is cooled by drawing cold air from the freezer. There is a tiny computer fan operated on a thermostat that turns on and off to suck air when needed. This fan activation breaker is labeled "Refrigeration" on the overflow control panel at the NavStation. The Compressor breaker on the main panel is labeled "DC Refrigeration"
The freezer has a thermostat and it is possible to run the freezer automatically, however we never did as I like control over when such a large current draw should take place. We typically run the freezer for one hour in the morning and one hour in the evening. This is enough to maintain temperature, you will need more if putting un-frozen items in the freezer or warm beer in the fridge. Plus we leave it on when ever the engine is running. This past trip we hit a record temperature of minus 24celcius (we had quite a bit of motoring) however we normally keep it at around -6. The current draw is around 40Amps per hour for compressor and cooling water pump and fan, higher on startup.
Components of Fridge
- Condenser
- Service Valves
- Compressor
- Dryer
- Collection tank
- High pressure/Temp cutoff device
- Electric Motor
- Sight Glass (for charging)
- Plexiglas door
Usage Notes:
- Occasionally when pounding into heavy seas, the bow would totally leave the water and air would get into the saltwater through hull used for the fridge cooling and cause cavitations in the centrifugal pump. Water would stop flowing, the unit would heat up and auto shut off. Always check for water on fridge startup, it comes out of the stbd side just by the jib winch. If water is not flowing I have added a bleed valve in the engine room just by the engine through hull, a big red T valve. With the fridge running, open the valve - taking care not to spray engine with salt water - until runs bubble free and close again. As our final sail was our first pounding trip in 5 years we had never experienced the fridge issue before. Ultimately I replaced the centrifugal pump with the spare diaphragm pump so the problem went away. The above notes are incase you revert back to the the centri-puppy pump again.
- During our stay in Kiribati the main 50Amp fridge breaker smashed. I confess it was me, I was upgrading to monster low current loss wire, unfortunately being unbendable it smashed the fuse when I was closing the panel door! As I had only a 40Amp fuse as a spare I had to use this, however as there was a peak load >40Amps it kept tripping. My solution was to move the cooling pump onto the sump pump switch thereby reducing the fridge load. Now to run the fridge you need to turn on the "DC Refrigeration" and "Sump Pump" on the control panel. Downside was you could now not use the shower as I 'stole' the pump out switch. This was not a problem for us as we always cockpit showered due to the oppressive heat. I will endeavor to find a new 50Amp Breaker and restore normal functionality, this note is just incase I run out of time.
- The fridge has a timer switch located to the right of the stove, clockwise for timer and anti clockwise for permanent on. This switch works but there is a break in the wire somewhere which I have not got around to tracking down. I have bypassed this switch and hence activate via the main switch board. It is well worth finding and fixing the bad wire as we enjoyed the freedom of setting the timer and leaving the boat rather than having to remember to turn it off after a set time.
- When the unit is turned on for the first time in a while (week or more) it will trip out a few times. Just keep restarting the unit and it will settle down, normally four or five trips gets it going.
Tools:
- Vacuum pump - just in case you had a catastrophic leak, once fixed you would have to evacuate the system and refill. Obviously as you are not a licensed technician (required by law in some countries), you would allow the repair man to use this pump :)
- Gauges - used in toping off. You are legally allowed to do this as long as emissions are kept to a minimum i.e. purging the gauges only.
- Nigel Calder Boat Owners Manual - Excellent section on refrigeration, with this you can do anything.
- Flare tool - used on copper pipe fittings
- Refrigeration spanner - a square spanner with a ratchet for compressor stem valves
Spares:
- Cylinder of Freon R-12. Legal to have on boat for topping off only.
- Vacuum pump oil
- Spare compressor
- Spare compressor head rebuild kit
- DryerTx-Valve
- Brushes for Motor (Just installed on this trip so contact Flemming Marine for new spare set)
- Cooling water pump