I've read through several posts about the refrigeration, but haven't hit on one addressing this specifically, outside of a possible thermostat or controller replacement. At issue is the fact that the original unit in our '91 cycles on constantly when the air temperature is above about 70 degrees F and no longer freezes, but ALMOST keeps things cool right up to around 80 degrees F air temperature. When the air temp is cooler it will cycle on and off with slightly longer pauses. (As I've had a mess of other things to fix/worry about since buying the boat last year if something has been working passably...)
However the fridge, all by itself, will drain not only one battery, but even both (battery switch on "BOTH") overnight on the hook, and it will even drain both NEW deep cycle AGM batteries if I have them plugged into the electronic Genius brand battery charger over the week at the dock. Only if I leave the old original continuous 14 volt output charger connected will the batteries be charged and the fridge still working when I return the following weekend. (This begs another issue about the Genius battery charging unit, but...)
Any suggestions on what I need to change out/check to increase the fridge efficiency and reduce the electrical draw? I read about checking the pins and will do that next weekend. Does this sound more like a thermostat or controller issue? Or something else? Any suggestions muchly appreciated!
Kevin Lenard
"Firefly"
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada
It's conceivable that an Adler-Barbour compressor running 24-hours a day would run a 100AH battery completely down if nothing else is putting energy back into it. Without knowing your battery capacity, beginning state-of-charge, and capabilities of your battery charger, it's a rather incomplete picture.
I'd check to make sure that the condenser is clean (that the thing that looks like a radiator next to the compressor) and that the fan is running and not blocked.
But I have to ask the question of how many of us are driving around a 1991 car with air conditioning that has never been touched? And so it goes with your Adler-Barbour, built years before the first President Clinton ever set up shop the White House. Might also just be time to admire the tenacity of your Adler-Barbor for hanging in there for a quarter of a century as you research for a replacement unit.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Kevin,
To follow up on Nicks comment; it really does not take very long to draw down a battery bank with your refrigeration. I replaced about 3 years ago my complete unit and it worked reasonably well or at least better than what I had. I think it would cycle for approximately 10 minutes and stayed off approximately 6 minutes. I believe the amp draw was about 5 amps so that is approximately a 3.3 amps/ hour while running. so in 24 hours that is a 79 amp draw on the battery. I have a 450 Amp hour battery bank and without anything being put back the bank would be dead in about 5 days.
The items that Nick suggests above are some of the first things you should do for efficiency and cooling performance. As you stated it could be the thermostat itself, but if it is running you may need to check a couple of other things. Kohlman states that the Alsor-Barbour units that the evaporator needs to have a light frost front to back and the frost should stop on the return side from the evaporator on the tube no more than a few inches. He also states that some of the issues with the thermostat are the telephone style plug. My unit wouldn't run or it would run intermittently when I got the unit where I could see it I found that the receiver for this connection was broken and actually wired it direct as Kohlman suggested.If you wish to really get into this you might wish to purchase his 12 & 24 Volt Refrigeration Manual. You can also find a lot of info on his website.
I got into recharging the unit and it is a very delicate balance and fairly time consuming. or it seemed as I had been dealing with the unit working intermittently. Once I found the electrical problem than getting the proper charge was not so bad. I ran out of season so I have not had a long run with the results I achieved. I have the amp draw now down to about 3.5 when running and it comes on about every 5 minutes for about 8 minutes with a setting of about 4. Within a 24 hour period the box is about 39 degrees and the evaporator is frosted. all over the outside as Kohlman suggests. If you do the math now the unit is running approximately 37 mins and draws about 2.15 amps per hour and within 24 hours would consume about 52 Amps there again would not take long (2 Days to draw off 100AH.I will record some more info over next summer, but with some effort and problem solving I think I have achieved a savings on amp draw and know that the box is running much colder now.
Gary Bain
S/V "Gone With The Wind"
Catalina 36', Hull #: 1056, Year: 1990, Engine: M-35
Standard Rig
Moored: Boothbay Harbor, Maine
Home: Auburn, Maine
Great advice, Gary. I will do a check on the connections, etc. and check the frosting after the check. I do know that when it is cooler outside the unit does have a light frost overall, but it cycles back on fairly soon after shutting off. Cycles constantly in warm weather and cannot keep up, so there's a steady draw that must be much higher than a new unit would pull. Many thanks and I'll get in there and will give it some TLC and see if I can urge her along for another season or two. KL
Kevin Lenard
"Firefly"
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada
Ha! I hear you, Nick. I have stuck a gold star on the little black tank and regularly give the old girl a pep talk, but never having had a fridge on board before (this is year two for us) I just thought it might be one of those hardy devices that goes forever like our diesel (OK, at under 1,000 hours I know she's about halfway to retirement). I'll check and clean the unit thoroughly. KL
Kevin Lenard
"Firefly"
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada