33. Question: How does Seawater Temperature Affect Boat Refrigeration performance? In your 12 volt manual section on selecting a refrigeration unit you separate the units by what works in cold climates but will not work in warm climates. On the Great Lakes we have 90° days the same as they do in the tropics so what is the difference?

Answer: The seawater’s temperature surrounding the boat’s hull has a major effect on the ambient air temperature inside the boat and plays an important role in the performance of a refrigeration system. Cruising area seawater temperatures are not listed as part of a refrigeration sales brochure but should be. Water temperature also must be considered if the refrigeration equipment selected is to be water-cooled. Failure to consider the effects of different seawater temperatures when selecting a boat refrigeration system is why many refrigerators perform poorly.

Good boating weather is when the temperatures are in the 70° to 90° F. range. In this country when there are good boating temperatures the water temperatures can vary in the north from 50° to 88° F. in south Florida the Bahamas and the Caribbean. When you think of California having good boating weather we forget the Pacific coast waters are cold, example, weather Station 46025 - Santa Monica Basin in August reported a seawater temp of 69° while Station FWYF1 - Fowey Rocks, FL the same day reported 86.7° F.

Ambient air and seawater temperature along with the box’s insulation and intended use, will determine the size and type refrigeration system for a particular boat. There are formulas for calculating the Btus of heat effect on large walk-in refrigerators that some think can be scaled down and used to project a small boat refrigerators total heat load. I believe the estimated heat load should be based on worst case conditions such as: Thermostat set to maintain 33° in the coldest part of the refrigerator box, normal daily product flow in and out of the box, number of people on board, ambient temperature of 90° F. and seawater temperature of 86° F. If the box has a front opening door add infiltration heat loss.. Using the method in my book for a six cu. ft. refrigerator box in worst case conditions, with three inches of good foam insulation, four people on board and a 14 inch front opening door, the heat load would equal 6440 Btu per day. If the boat were in Santa Monica CA. instead of in the tropics . Where the seawater was 17 ° cooler there would be a 20% to 30% reduction in the daily heat load projection. In this same comparison if the condenser were water cooled a 34% reduction in required daily Btus are possible. The problem with seawater cooled condensing units is they begin to loss efficiency when the water temperature drops. If the same water cooled unit that was designed for the tropical conditions above were operated the same day on a boat at Station 46026 - SAN FRANCISCO with a water temp of 54.5° its performance will be less than good. When selecting a refrigeration unit you want to error on the cool climate side not the hot climate side.

On pleasure boats when the refrigeration compressors are larger than 1/6 Hour power the process heat is almost always removed by seawater. Maintaining a reasonable temperature range of the condenser cooling medium, air or water is important, too low or too high a temperature will affect the systems performance. Large commercial water cooled refrigeration units have water flow regulators to maintain the high side pressure in a system, but they are not available on the small systems. Two of the pioneers in pleasure boat water cooled engine driven refrigeration Crosby and Grunert used manual seawater bypass valves to keep the high pressure refrigerant in the proper range. With an adjustable water bypass the same system can operate efficiently in the Pacific or the Caribbean. It seams like refrigeration systems manufactures located in cooler water climates tend to error more when it comes to adequate seawater cooling for use in the tropics. The small refrigeration compressors with capillary tube expansion devices are very sensitive to temperature variations in the cooling medium therefore water-cooling is a poor choice unless operated in 55° to 75° F. waters. Small air cooled condensing units are much more suited to varying air and water temperatures. Abler Barbour and Technautics are two of the companies that design with adequate air-cooling for the tropics and if the same units are operated in a very cold climate the airflow across the condenser can be restricted or a portion of the air recycled.

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32. Question: Can you advise me of your recommendation in choosing a running speed for my BD35? This is in a well insulated cabinet Why does faster speed equal less amps.{is this greater efficiency}? According to a spec sheet, the faster the speed the lower the amps? Would the forced air evaporator be a better choice than the standard evaporator? What would you expect a running pressure to be at any given cabinet temperature?
ANSWER: I am not sure which unit you have but the BD35 compressor is speed adjustable by adding resistance to the thermostat wiring circuit. With no resistance in the circuit the compressor will run at 2000rpm and by adding resistance the speed can be increased. As the compressor speed is increased the amperage increases.The key is to match the compressors speed output to the evaporator's ability to absorb the heat and this is what the manufacture does when he builds the refrigeration system. When you purchase a refrigeration conversion kit to install in an existing ice box the third part of the equation is to select a refrigeration system that is the correct size for the box to be refrigerated. There are a number of methods used to control speed and performance described in my new book.

A normal refrigeration system will cycle from two to ten times per hour and the evaporator will have a complete cover of frost. Failure to cycle means poor performance. Excessive cycling indicates a thermostat problems or the evaporator’s size is inefficient for box size. Lack of frost on evaporator means low on refrigerant.

I assure you, you are misreading the specs, the compressor draws 5 to 6 amps at 3500 rpm.

The BD35 with a forced air evaporator is a good choice for a small cooler but I do not recommend them for a refrigerator.

Don't fool with the pressure. E mail Adler Barbour or go to their Forum and post your question. Be sure to give them the size of the box, the amount of insulation, type of lid opening, the ambient temperature and the condensing unit model number.

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31. Question: What are the prospects of converting my Sea Frost engine driven from Freon 12 unit to a 134a refrigerant?

I currently have some f-12, but can for see the necessity to convert to 134a refrigerant. Sea Frost has a conversion unit , but it cost approx. 1200-1400 dollars. It includes a new compressor, condenser, and other add-ons. What about the automotive conversions which are available at Wal-Mart for about $40.00.

Answer: Many engine drive systems are converted to 134a refrigerant by the Wal-Mart/Auto part store method, which is remove R12 refrigerant, dump in Ester conversion oil and fill with 134a no other items are changed. The problem with 134a refrigerant is the line connection to the bottle will not fit the standard freon gauge connections. An adapter is required to make the connection between the bottle and yellow servicing hose.

There are two problems with the Sea frost engine drive system when converting it to 134a. 1. Most engine driven systems hold more refrigerant and have areas where the excess oil can be absorbed this is not true with the Sea Frost system. The oil needs to be drained from the compressor, oil blown out of lines, condenser and holding plate. The receiver-dryer must be replaced them it can be serviced with 134a refrigerant. The conversion process requires recovering and recycling old refrigerant, leak testing and vacuuming air and moisture before final service.

2. Sea Frost water cooled condensers are designed for non tropical seawater conditions of less than 80 degree F. If the system is to be operated in south Florida or other tropical waters I would stay with R12. Once converted to the ester conversion oil and 134a the refrigerant can be changed back to R12 by removing the 134a and refilling with R12 if the boat is moved to the tropics. There is still plenty of R12 in these areas.

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30. Question: How can I cool all areas of the refrigerated box?

We have an old Adler Barbour refrigerator system on our boat. The box is
very deep and we have a Plexiglas shelf that we put in so my wife can
reach the items. I drilled a lot of 1/2" holes in it and would like to
know if you could recommend a battery operated fan that we could put in
the bottom to circulate the cold air up to the shelf.

ANSWER: There is a very small one inch 12 volt square muffin fan sold by Radio Shack for $9.95 that will solve your problem. It only draws 1/10 amp it should be powered anytime the refrigerator is in use , this means all the time except when refrigerator is turned off.Installation is simple, Buy a length of 18 or 20 gauge red and black wire that will reach to a power source. Cut a one inch hole in shelf and connect wires to fan, Mount fan on plastic so that air is forced from top box to below the shelf. Before connecting the red wire to a power source install a two amp inline fuse and a switch.
Top opening refrigerators and freezers have poor air flow and therefore the temperatures will vary from side to side and top to bottom. Without the air movement in a refrigerator or freezer temperatures tend to stratify in layers. Most commercial refrigerators are constructed to allow the natural movement of warm air rising and cold air descending across the evaporator to tumble the air. The addition of a small fan can help most refrigerated boxes. I recommend a one inch square muffin fan that runs at all times the refrigeration is in use. I ran over two hundred test to prove what works and what does not, most are in my new 12 volt manual.

FAN TEST: The Thermostat was locked and outside air temperature maintained between 79 to 82 degrees F. for these 24 hour tests. ( could not display the Data Charts ) In test 119 the food product blocks the transfer of heat. In test 120 the small airflow from a one-inch muffin fan tumbling the air lowered the temperature eight degrees at the far end of the box. The fan increased the efficiency of the evaporator and increased the Btu output from the compressor.

29. Question: How can you compensate for the voltage drop caused by a Battery Isolator Diode?

Answer: Battery Isolators work fine when power is supplied from alternators with adjustable voltage regulators. Sailboats are now taking advantage of the improved alternative energy sources, wind, solar and water to charge their batteries. When charging deep cycle house batteries five to ten tenths of a volt drop is a major loss in efficiency. There are devices called Battery Combiners or Battery Separators that automatically connect battery banks when a charge voltage of 13.2 volts is available from either battery bank. When the charge voltage drops below 12.8 volts the battery banks are separated. These devices are available from several sources in several sizes and some have a separate manual control circuit that can be used for engine starting. There are drawings in the manual showing how battery switching is accomplished with a combiner and how to control the refrigeration unit with a combiner.

28. Question: Why would I want air cooling when water is more efficient?

Answer: Boat refrigeration systems smaller than ¼ HP are generally air cooled for best performance and long term reliability. There are few conditions where the seawater cooling can out perform air cooling on these small units. To dispose of the heat in a boat from a small Danfoss refrigeration system is about the same as disposing of the heat generated from one person onboard, three hundred BTUs per hour. It is true that heat from larger refrigeration systems must use seawater because the heat can not be disposed adequately of onboard a boat.

27. Question: My old 1983 Adler Barbour seams to have a leak, how to repair?

Problems: Loss of cooling capacity. I measure 8 degrees F differential across the condenser. Cools but not to the extent previous. Has been slow decline over years.
Attempts to correct problem: Cannot find port to add R12. Is it feasible to disconnect the quick connects, take the compressor / condenser unit to a refrigeration shop, get it recharged, and expect the quick connects to work a second time? Do such shops have adaptors to fill these units?

ANSWER: Before we blame the Refrigerant for the problem, are you sure that the condenser is not clogged with dirt and the air flow is good through the condenser. I run into this problem all the time with these old units its usually their aluminum evaporator corroding through and very small holes are opening up. These leaks can start up so small that it can take months for the refrigerant to leak out and the leak rate will get worse over time. I don't recommend you take the unit out for service. What I recommend is not a proper fix but it is the best approach on a twenty year old system with a problem. Buy a clamp on servicing valve 5 to $7 called a Self-Piercing adjustable line tap valve that fits a 1//4 inch line. The valve is clamped to the short stubbed off line coming out of the compressor dome or on the suction 1/4 inch return line. Follow the direction that come with the valve cleaning the line good and no nicks where the valve is to be installed.

Purge air from the servicing hoses. Add a small amount of only R12 refrigerant. Adjust the refrigerant level over a two hour time period to obtain a frost layer over the entire evaporator but with no frost returning out side the box to the compressor. My book 12/24 volt Refrigeration Manual has much more detail on this.

26. QUESTION Replacement for Freon 12
A quick question: Heard through a list online of a new direct replacement for R12. It's supposed to be some percentage more efficient.I can't remember the details and they are on my other computer but I was wondering if you are familiar with any direct replacements. I have 2 Cold Machines on board and while they are old they still work well.Since they are both R12, I am concerned what to do when they need recharging. I have stockpiled about 8 one pound cans of R12 when it was available anywhere. This should get me through a recharge but at some point I better consider a change. Would appreciate your expert opinion.
Keep up the good work! Thanks in advance,

ANSWER
As far as I know there is no direct replacements for Freon-12. Unless the manufacturer of the compressor lists a refrigerant as approved I will not use it. I worked on a system today with junk refrigerant in it. Servicemen are getting rich from oil and refrigerant mistakes. Your system holds less than ½ lb. and you should not need to service your system until the evaporator
Needs replaced. To preserve your spare cans protect then with oil or wax to prevent rust.

25. QUESTION Converting to another refrigerant
It is sometime ago, that we have had contact about our fridge-system on board of our yacht. We have a Sanden SD 505 compressor and used up till now Freon R 12 and are very satisfied with it, only sometimes we lost some gas and had to refill the system. So far that was no problem, while we could buy the Freon R 12 In small containers up till 12 kg. (not available in Holland)For the preparation of our sailing trip for next year, I went to my dealer here in Portugal, where we could buy the bottles but he informed me, that now also in Portugal R 12 is forbidden and not available. I am not in the position to check which
alternatives have to be used and which other things, dryer, oil, etc., has to be done in case of refilling with a good alternative gas.

ANSWER
Yes you can convert your engine drive 505 compressor to 134a refrigerant. R134a is used in this country in all new autos and can be purchased by anyone. It works as well as the Freon R12 .
To make the conversion, you will need:

four one pound cans of 134a refrigerant
A standard Freon servicing dual gauge set
A 134a tap a-can with hose and quick-disconnect
A male R12 to 134a service fitting
A ¼ inch flare union ( Picture on page 114 and 131 of Do-it-Yourself Refrigeration).
5 ounces of Polyester conversion oil. This is available in most auto parts stores.
IMPORTANT DO NOT USE PAG OIL which is used in new cars. A new filter dryer.
PROCEDURE
Remove all of the old refrigerant. Be sure that air does NOT get into the system. If air does get in, a vacuum pump will be required to remove it.
Remove compressor from its bracket do not remove hoses
Remove fill plug from top of compressor
Turn compressor over and drain out the oil. Don't be concerned if only a small amount comes out.
Pour in 5 ounces of the correct conversion oil and replace the fill plug with an O-ring be careful not to over tighten or you will strip the threads.
Reinstall the compressor and replace the dryer.
Connect the old Freon gauge set blue to suction side, red to pressure side.
There is no need for flushing the system
Install the 134a tap-a-can on a can of 134a. Do not puncture can yet.
Screw the ¼ inch flare union onto the end of the end of yellow hose. See Page 131.
Screw the male 134a service fitting onto the other end of the ¼ inch union
Now snap the tap-a-can disc-connect onto the male end.
Now that all connections are made, puncture the can and purge the hoses.
Pressurize the system and check for leaks with soap and water. Follow leak check procedure in the book.
Finish servicing the system.
The new oil and refrigerant will mix with the old oil and the system will work as good as it did before.

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24. QUESTION Mixed Refrigerant Problems and Converting Refrigerant with air in system
I had an engine driven compressor and I relocated it on a manufactured genset. The genset was sized up to run the compressor. My question is since I removed the hoses to do this alternation and now I have replaced the hoses and am ready to start up the system, what procedure should I use to evacuate the system and also Technautics furnished inline filters to be installed annually. Do I put in a net filter before or after I dry out the system. How and when do I add new 134 and also on the 12v system I possibly made the mistake of putting in 12 in the system as there was no indication of what was in it and I was at sea and tried to get the system up. If it required 134 what should I do?
Help needed! I sail 10/25, much thanks

ANSWER First the engine driven system .
I don't know what procedure you were given to convert to 134a or what model compressor is on your system so I can give only a general recommendation. To make the conversion you will need:
four one pound cans of 134a refrigerant
A standard freon servicing dual gauge set
A 134a tap a can with hose and quick-disconnect
A male R12 to 134a service fitting
A ¼ inch flare union. Polyoester conversion oil which is available in most auto parts stores.
IMPORTANT DO NOT USE PAG OIL used in new cars. A new filter dryer.
THERE ARE PICTURES IN MY BOOK OF THESE ITEMS
Procedure
Remove all of the old refrigerant
Remove compressor from its bracket
Remove fill plug from top of compressor
Turn compressor over and drain out the oil. Don't be concerned if only a small amount comes out.
Pour in the correct amount of the correct conversion oil and replace the fill plug with an O-ring be careful not to over tighten or you will strip the threads.
Reinstall the compressor and replace the dryer
Connect the old Freon gauge set blue to suction side, red to pressure side.
There is no need for flushing the system
Install the 134a tap-a-can on a can of 134a. Do not puncture can yet.
Screw the ¼ inch flare union onto the end of the end of yellow hose
Screw the male 134a service fitting onto the other end of the ¼ inch union
Now snap the tap-a-can disconnect onto the male end.
Now that all connections are made, puncture the can and purge the hoses.
Pressurize the system and check for leaks with soap and water.
Connect a vacuum pump to the yellow hose and evacuate the system for one hour. The complete system and holding plates must be warm above 80°F. if possible.
Close both hand valves on gauge set before stopping pump.
Connect yellow hose to 134a bottle and purge yellow hose again.
Finish servicing the system. Two one-pound cans should be enough DO NOT ADD TOO MUCH High pressure of 150 is too much.
Run system until holding plate is frozen sight glass at this point should be clear.
The new oil and refrigerant will mix with the old oil and the system will work as good as it did before.
Mixed Refrigerant
How do you know the compressor was a 134a unit?
How did you know how much refrigerant to but in? Did the system work ok?
What 12-volt compressor do you have?
Is there a receiver tank next to the compressor and an expansion valve at the holding plate?
Vacuum out all the refrigerant for 20 minutes. And add the correct amount of the right refrigerant.

23. QUESTION Under Water
I have an engine driven compressor driving a holding plate. The boat was damaged at the dock and was awash for 4 days everything was hosed with fresh water. The compressor appears OK and the holding plate as well. Now when I next visit the boat I would like to get the refrigeration up and running. I assume the timer is shot after having been under water. What should I do to restart this system and in what order? I will not hold you responsible if anything happens.
Please point me in the right direction.

ANSWER
My experience with downed boats indicates very little damage is done to engine refrigeration systems. The electrical wiring is the problem

Wash all areas with soap and water and then fresh water.
Let dry and spray and wipe all areas with WD-40.
If your systems has high and low pressure switches flush with WD-40.
Replace the wind-up timer. If an electric pump is used to circulate the refrigeration cooling water replace it too.
You will experience wiring terminal problems at some point so carry extra wire and terminals.
Most compressor clutch coils are sealed but the amperage draw should be checked. It should be less than 5 amps.
After the system has run several hours, remove the compressor drive belt and spin the pulley to see that the clutch bearing is in good condition. Water cannot get into the compressor but the clutch sealed bearing could lose its grease.

22. QUESTION Engine Drive Compressor Failures

I am on my third compressor. After being away from the boat for a month, I turned on the engine compressor and it started squealing and seized up. I called the manufacture and they said it was because it lost Freon, but this is bologna
since freon hisses out when I depress the Shroeder valve. I converted it from R-12 to R-34. The Freon is supposed to have a lubricant in it. My next step is to have a reefer man remove the Freon and weight it. Normal is about 1 lb.

ANSWER
There are many reasons why compressors fail; leaking sea water condenser, lack of lubrication, contamination, system blockage, poor design application and the new or replacement compressor might have been defective. The system you have is generally a good one and performs well, but it does have some service problems such as: over-tightening light weight fittings causes damage and permanent leaks and the system is not designed to protect itself from loss of refrigerant. After the second failure, an effort should be made to determine the cause of failure. It is not the manufacturer of the system as there are thousands of systems like yours out there.
Before making recommendation on how to proceed, I would need to know more of the history of the system.

How long did each compressor last before failure? How large is the pulley on the engine?
Have there been any changes to the system other than converting to 134a?
When was the refrigerant switched from R12 to134a, before which compressor change?
On converting to 134a what oil was used?
Are there any signs of oil leaking from the system, if so, is it larger than a tablespoon full
You must know if the oil was Polyester Refrigerant Conversion Oil.
I have seen a trend in compressor problems like yours this year. If you can answer the above questions, I can recommend to you or your service mechanic the proper correct action.

21. QUESTION Using Water Tank To Cool Refrigerant

I have just reviewed the info on your refrigeration site as I am about to restore my boats refrigeration.I did have one question and wanted to get your thoughts. I am leaning toward a water cooled as opposed to an air cooled system. My dilemma is that it is difficult to get water cooling to the area where the compressor/condenser would be mounted. I have two 230 gallon fresh water tanks which are easily accessible and integral to the hull/bilge area. Would it be possible to use this water for cooling the refrigeration system by taking from the tank, cooling the refrigeration system and then returning it to the tank. Since the large volume of water in the tank is essentially at the same temp as the outside sea water its seems to me this is feasible.

ANSWER
I don't know the size of the box or boxes you wish to refrigerate or if your hull is metal or plastic so I can only give you an example. If a well-insulated box operated in the tropics were split into a 4 cu. ft. refrigerator and a 2 cu. ft. freezer it would need to have 4800 btu of heat removed per day. If the heat were deposited into a full 230 gallon water tank, the tank temperature would be increased 2- ½ degrees per day plus another 1-½ degrees due to compressor heat.

20. QUESTION Thermostat Adjustment
If I want to adjust the temperature range of the Thermostat, should I put "more" of the sensor in the bracket, or "less?" During the hot summer, my fridge does not seem to get as cold, but the inside cabin temp does get quite warm. I was wondering if I can come up with a summer setting for the thermostat sensor. By the way, I have a Frigoboat, which just had the control module changed.

ANSWER
Changing the thermostat range will lower or raise the box temperature only if the thermostat is the problem. If you are saying that when the thermostat is set as low (cold) as possible, the compressor is cycling off and on without reducing the box temperature with each cycle, adjusting the thermostat range will help.
To answer your question clamping less of the capillary tube under the evaporator will lower the thermostat temperature setting. Removing the tube and letting it hang free will sometimes turn a refrigerator into a freezer. A properly adjusted thermostat range would be to have the desired temperature at mid range 3 or 4 on the dial.

19. QUESTION 12 Volt Danfoss Start Problem
My 1984 Islander 36 has an Adler Barbour Cold Machine refrigeration unit (I'm not sure of its age). This is our first year with the boat, and our first experience with onboard refrigeration. The unit cools down quickly and seems to work well. Recently, however, we've noticed that after the unit has been running for about two hours it will cycle down for a short while (a minute or less), we'll then hear a faint beep, and then it cycles up again. This stopping, beeping, and starting has become increasingly more noticable, but the unit's cooling capability seems to be fine. I don't have an owner's manual or any other documentation , so I don't know what to make of the beeping. Do you have thoughts about what it might be? Is the unit about to fail? Any insight you could provide would be greatly appreciated. Thanks.

ANSWER
Repeated failure of start cycle beep is caused by a program in the electronic unit. It is programmed to stop the compressor if:

The voltage is below 11.5 volts during start - Check batteries for charge- Check for a resistance connection. The best and quickest way to do this is run a temporary set of wires from a fully charged battery to compressor. The wire size and polarity is important.
The fan or if water-cooled, the pump is drawing more than one amp.. To check, disconnect one of the wires to fan. If it starts OK replace fan.
The compressor is going bad and drawing more than 7 1/2 amps. To check install an ammeter in the power wire to the refrigeration unit It should draw 5-6 amps when running. If more than 7amps the compressor is about to fail. To do this test the unit must run because start up amps will exceed 7 for a very short time.

The electrical unit is defective. Install a new $200 unit.

FOLLOW UP QUESTION
Thanks for the quick response. Do you think a novice (i.e., me) would be able to perform the troubleshooting steps you suggested? I don't have any documentation or diagrams of the unit, and Adler Barbour didn't want to send/sell me one because I don't know the unit's age. Does your book contain enough specifics to help me with this, or should I call a pro? (It also happens that I'm located only a couple of towns away from Adler Barbour and they gave me the name of refrigeration specialist who used to work for them).

ANSWER
You have asked a question I cannot answer as I can't evaluate your tour skill level. The problem you are experiencing is an electrical problem not refrigeration. Step #3 would require an amp meter and if this test fails, a refrigeration repairman to replace the compressor. Although I want to sell as many books as I can, my book does not provide the basic skills you need to know how to work with electricity. The beep sound you heard indicates you have one of three models each has a large positive and negative power wire. All three have small red and black fan wires. The chances are your batteries are not at full charge or there is a loose connection at one end of the power wires.

18. QUESTION Refrigerator Stops Running
Manufacturer of the system: Adler Barbour Super cold machine
Problems: The unit was installed new in 1992.We are on Lake Champlain, NY. The optional water-cooling option is NOT installed. The unit in located under the port settee in a hunter 35.5. We have installed 2 additional ventilators with louvers to create air circulation under the settee. These are noisy. We are using them all the time except when going to bed while sleeping on board. We use the boat every weekend plus our vacation. The boat is out of the water 7 months per year. The unit is in function running continuously from mid-May to mid-October.
Since we bought the boat 2 years ago, the hunter installed analog amp meter indicate 7,5 amps when the unit is in function, 8,5 to 9 when additional ventilators are in function. The regular cycle time is about 8 minutes on / 10 minutes off, in 80 degrees temperature. The unit is cooling very well the fridge and freezer.
During the last 3 weeks (our vacation) the temperature went up to close to 100 deg. inside the boat during the day. Not normal in our area. The unit performed well until one day at 4:00pm, I noticed the amp meter registering only 4 amps. The ventilators were functioning but the compressor was not. I turned the breaker off for 30 seconds. At restart, the fans were working but the compressor did not start. Did these 3 or 4 times. The unit was very hot to the touch. I turned the breaker off for 3 hours. Everything went back to normal on restart. The following day, the same thing happened. We put the same cure and it went back to normal. It did it again the following day. We could hear the fan running, but we could not hear the bubbling like sound when pressing our ear on top of the fridge door. Is this bubbling sound normal?
Last week end, the same thing happened while the temperature inside the boat was about 80 deg. Same cure was applied successfully. We are not in the boat during the week, but upon our arrival on Friday night, everything is OK. The ice cubes are rock hard and everything is cool.
Attempts to correct problem: Questions -Am I slowly loosing the electronic or the compressor or else?
Is there a temperature sensor that will start the ventilator if the unit is too hot?
What is happening???
Is 7,5 amps too high when the unit is in function? I estimate the unit running 24 minutes per hour when temperature is about 80 deg. inside the boat, consuming about 3 amps per hour or 72 amps per day.

ANSWER
I believe there are answers to your questions and the corrections may be simple but I need more info. A quick review tells me:

There are two models of the super cold machine and their controls are different.
There are two ventilators that are noisy.
Cycling 8 min. on 10 off indicates unit is not over charged.

The question is what safety device is stopping the compressor.
I need to know the following:
1.Is your compressor a BD2.5 brushless that incorporates an external electronic control box connected by a large rubber covered cable. Or does the compressor have separate 12-volt wires connected to the compressor and no electronic module
2. Do the fans in the ventilators look the same as the fan on the condensing unit?
3. Where are the wires from the vent fans connected (very important.)?
4. What size and how long are the power wires from the battery buss to the unit?
5. Does the compressor-stopping problem only occur when not connected to shore power?
6. Does the compressor fan stop when the compressor stops? You indicate the vent fans do not.
7. Are you sure the compressor fan is running? Its failure to run will stop either type of compressor.

Follow up
Hello Richard, following my visit to our boat this weekend, here are the answers to your questions. Hope you have enough details...
1. If the electronic module is a 3 X 6 inches stainless box ( like the picture available in current catalog showing AB products), mounted opposite side to the fan, our unit does not have one of these. Our unit has a small plastic covered box (2 X 2 inches where electrical wires are connected) mounted on the front side of the compressor thank
2. Do the fans in the ventilators look the same as the fan on the condensing
unit? They look the same.
3. Where are the wires from the vent fans connected (very important.)? They are plugged in a small connector box on the extreme front /right corner of the unit.
4. The power wires from the battery buss to the unit are what size and how long
are they? The black and red wire id 5/16" including the rubber insulation. The length is 21 foot +/- 1 foot from the compressor unit to the main DC panel breaker.
5. Does the compressor-stopping problem only occre when not connected to shore
power? In all this situation happened only 4 times to my knowledge, while I was using the boat, always at anchor in mid to high temperature. When arriving at the boat when we are plugged to shore power, I never noticed that situation.
6. Does the compressor fan stop when the compressor stops? You indicate the vent fans do not. What I was trying to explain is that the Compressor fan (the one supplied with the unit) is not stopping. It runs continuously without the compressor running. The additional fans are also running without stopping. I can if I want turn them off with a switch I installed. When we turn them off for the night, we always remove the cushion on the settee and open the wood panel over the unit to create additional ventilation.
7. Are you sure the compressor fan is running? Its failure to run will stop
either type of compressor. I am absolutely positive that the compressor fan is running this fan alone, give me a reading of 4 amps on my panel amps meter. I read About 6 amps with the additional fans running. I know this since the additional fans are noisy, I put a small switch on the additional fans to shut them down at night while sleeping in the boat.

ANSWER
It appears that you have the older super cold machine with an internal brush motor.

The only device that your unit has to stop the compressor other than the thermostat is a thermo-overload switch.
I don't believe the problem is overload or over charged because the amperage is not high and the unit is cycling on the thermostat.
The overload-switch is located under the plastic cover on the compressor. If the problem were occurring in cool weather I would suspect this switch. It sounds like the switch is doing what it is supposed to do which is to stop the compressor when it gets too hot.
These units are designed to operate at 90 + °, so the problem is why with three fans is it still too hot.
Have you removed the condenser fan and cleaned the coil fins condenser? Are the vent fans set up so that one moves air in to the area and the other move the air out of the area?
These units perform best when the air that passes through the condenser is not allowed to pass through it again.
Dirt in the condenser and air flow sounds like the problem.

17. What equipment would be best for my needs:

I plan to live aboard in the tropics and my box is smaller than 4 cubic ft, with three inches of good insulation. I also plan to live at anchor away from shore power.

ANSWER: In the tropics with two people on board, I would expect your daily requirement to be 2400-3400 Btu. I would recommend a small 1 2-volt DC refrigeration conversion unit with chamber evaporator. As your daily refrigeration load would be 56 AMP hours, your house batteries should be four times your daily load. Be sure to add AMP hours for the operation of your radio and lights. To reduce engine running time, I would recommend a high output alternator and a smart voltage regulator. Also, a good investment for a live aboard boat that will be at anchor most of the time is a wind generator.

16. Can I run a 110-volt unit off an inverter:

I want to use a ll0-volt refrigeration unit instead of a 12-volt unit. I would want to run the 110-volt unit off an inverter when I am away from the dock. Is this feasible?

ANSWER: 110-volt refrigeration units used on boats are an adaptation from the standard home or commercial refrigeration units. They normally consist of hermetically sealed compressor units identified as low back pressure units so that low freezer temperatures can be maintained. They can either be air or water-cooled. The big problem with 110-volt units is the amperage required to start the unit. For example: The average 1/2 horsepower will take around 1800 watts of power to start it, and it will run at about 900 watts and produce somewhere around 3000 Btu of cooling per hour at 900 watts on a 90 degree day. If you power this unit through an inverter that was 95% efficient you would have a one hour drain on your 12-Volt batteries of 83 AMP hours. At high amperage, the inverter is much less than 95%. Any time the refrigerator is running the alternator must be running. This system is only recommended for emergencies.

15. My box is larger than 10 cubic feet. What type of refrigeration unit do you recommend:

ANSWER: There are some important factors that you must know before determining the size refrigeration unit to install in any icebox conversion. The most important factor to take into consideration is the amount of insulation. Three inches of insulation is recommended for a refrigerator and four or more for a freezer. This insulation must be closed-cell foam with an "R" factor of at least 7 per inch.(see insulation)

The size of the box, and shape must be considered. Boxes that are long and low require a different type of evaporator/holding plate than a tall or square box. Other factors would be the number of crew and the climate where the boat will be operated. A boat that is operated in the Northwest Pacific or the Great Lakes or East Coast would require a different size system than a boat that would be operated in the tropics. The number of people on board and any special refrigeration requirements must be taken into consideration. The ability to produce ice cubes requires one level of refrigeration, keeping ice cream solid requires another level, and the desire to quick freeze large quantities of fresh fish another level. So a thorough understanding of Your equipment and needs is required to properly design a refrigeration system.

14. How big a box can I refrigerate:

Answer: What limits the size box that you can convert into a refrigerator is the difference between the amount of energy required versus what is available. For example: If a box was to be refrigerated with a 12-volt unit, the energy available would be the size of the batteries and the running time needed to recharge them. An engine drive system, which produces the maximum BTU per hour would be limited by the number of minutes or hours that you wanted to run the unit per day. Normally a box or combination of boxes less than 20 cubic feet can be easily converted with holding plates connected to an engine drive system.

13. How many holding plates can be installed in a box:

ANSWER : The maximum number of holding plates is really determined by the total amount of tubing within the holding plates. I saw a boat that had seven holding plates all connected in series to one engine drive compressor. I believe that once you exceed a hundred foot of tubing in the aggregate plates on a single expansion valve you will run into suction pressure problems.

12. How many boxes can be refrigerated from one engine drive compressor:

ANSWER : I have three separate box systems connected to one engine drive compressor, and the system works exceptionally quite common to have two Separate boxes refrigerator and freezer on separate sides of the boat connected to the same compressor. In commercial refrigeration systems, it’s not uncommon to have from five to seven units connected to the same compressor.

11. When do multiple boxes need dual controls:

ANSWER: When two boxes are operated at different temperatures such as a refrigerator and freezer box would be, it is desirable to have controls on the refrigerator box to shut off the flow of refrigerant when the evaporator temperature of the refrigerator holding plate has been satisfied. Otherwise, items in the refrigerator section would freeze before the freezer box temperature had been satisfied. To save expense many dual boxes have had refrigerator/freezer conversions without dual controls. They either installed a smaller holding plate in the refrigerator or covered a portion of the refrigerator plate reduce rapid heat transfer, or by adjusting the super heat much lower in the refrigerator box to compensate for the temperature difference.

10. Can I connect two separate systems to a single holding plate:

ANSWER: Yes, if the holding plate has dual coils. This keeps the two systems totally independent of each other.

9. If I have two systems connected to the same holding plate can I run both systems at the same time:

ANSWER: Yes .

8. If I decide to go to a system using holding plates, how do I know what size holding plate to install in the box:

ANSWER: A simple rule of thumb is, if a refrigerator has three inches of polyurethane foam insulation it will take approximately a half gallon of solution in the holding plate for each cubic foot of refrigerator. If the freezer has four inches of good foam, the holding plate will require one gallon of solution for each cubic foot of freezer.

7. is well insulated and I've heard that holding plates that are connected to 12-volt systems are very efficient.

ANSWER : Most boat refrigeration systems require storage of energy because the engines are not operated 24 hours a day. Energy can be stored in refrigerator holding plates or it can be stored in batteries. There is a 15% energy efficiency improvement by using the holding plate to store the energy with a 12-volt system, but there are some drawbacks. The energy efficiency is achieved by less cycling time on the 12-volt compressor, but the primary disadvantage is that you give up the evaporator chamber in your ice box where you can keep a small quantity of frozen food or make ice cubes. If you have a small box where the entire temperature is to remain at a constant temperature, the holding plate will do this better than the evaporator, but where you would like to have separate temperature gradients for a combination refrigerator/freezer the evaporator chamber is better. For the weekend sailor, where the boat is connected to shore power all week. The energy could be stored in a holding plate for weekend of sailing. With this arrangement, you would require very little 12-volt power.

6. Question We have an engine drive refrigeration system with a single coil holding plate so when we are in a marina we must still run the engine every day to have refrigeration. A charter boat we were on had a separate 110 volt AC compressor connected in series with the engine drive compressor can this be done to our system?

Answer: As to the system you describe there are better ways to achieve the dual system, but without knowing the size or shape of your box along with the size and location of the holding plates I can not give a good recommendation. Sometimes, one solution is the addition of a completely separate 12-volt system with a separate evaporator plate or a small holding plate. Large commercial systems have been successful in using a single coil evaporator as they have electric heaters in the oil pan of the compressor to ensure that the oil remains there. They also have an electrical control circuit to pump down the system before stopping the compressor.

Several methods have been tried on boat refrigeration systems to return the right amount of oil to the right compressor on single holding plate systems. After replacing many compressors on these systems, I strongly recommend against the use of a single coil. All of the refrigerant may migrate to a frozen holding plate on shut down and take most of the oil with it. Since the engine drive compressor uses a fraction of the oil quantity of the larger 110-volt unit, it is generally the first to fail. Other reasons for not using a single coil are:

The second compressor can be contaminated by the first

A single failure can cause the backup system to fail.

5. Question I am building a regular size box that needs refrigeration and my alternator is 300 watts. The boat is equipped with two 100 amp hour Batteries. What type refrigeration should I install?

Answer: Without information on your box size, the boating area and amount of insulation, it is difficult to make a recommendation for a refrigeration system. For example: A box of four cu. ft. with three inches of good insulation using an Adler Barbour cold machine or like unit, might take 2800 Btu, s per day or 47 amps. Hours. Your 300watt alternator with a standard voltage regulator would have to run 4 to 6 hours just to replace the power used by the refrigerator. Normally I figure the other 12-volt daily usage at 50 amp hours. This would mean a total of 100 amp hours to be replaced per day. The house battery system should be sized to four times the daily load. If you build a box this size I recommend the following:

For weekend and 2 to 3 week vacations

Install a 12-volt air-cooled Cold Machine with a chamber evaporator.

Install an inexpensive battery voltage meter that reads only 12 to 13 volts full scale like those used on electric golf carts.

Install two additional group 27 inexpensive deep cycle batteries.

Use battery charger when at dock and add water to batteries each week when refrigerator is running off charger.

OPTIONAL:

Add one 75 watt solar panel or High output alternator with smart voltage regulator, if you are not going to motor several hours per day.

Install a 15 amp. Or larger smart charger.

Recommendation for extended cruising:

Add to #1. Two solar panels or a wind generator

Install a 75 amp high output alternator with a smart regulator

Install a good grade of lead acid batteries, four to six are recommended.

OPTIONAL:

If the plan is to upgrade the boat with Inverter, Microwave or Water maker, then I recommend a dual system Engine drive and 12 volt system connected to a dual coil holding plate.

If the box changes these recommendations will change.

4.    Question from email: I am writing because I am having trouble with my engine driven cold plate system. The 12 volt is ok that is also connected to both holding plates. I have a Westsail 32 . First let me remind you of some system history. Three months ago before leaving for the Bahamas, I thought the engine drive system needed refrigerant. Unable to get in touch with you at the time, I added R134 until the bubbles disappeared. It worked well for a week and then when I got over to Bimini, if I remember right, it was the high pressure switch that was cycling on and off. This time I was able to get you on the phone. You said that I had added too much R134 and to let some out until it stopped cycling, regardless of the sight glass. I did, and it has worked great up until now.
     If I am diagnosing this problem correctly, it sounds as though we have a slow leak some place. I have used soap bubbles on all the joints and also used a very good quality leak detector without detecting any leaks. We are over in Man-O-War Cay where the water temperature is 86°F and stagnant, the outside air temp is 96°F today, and my engine room temp after 1 1/2 hours running is 110°F. Should I just add R134 until it stops cycling and stays on, or just ignore it until the weather cools down some. Or does it sound like I may have some other problem?
    Answer: As the sea water warms up the high pressure increases . Check the high pressure switch. It should be set at 175 psi. Increase it to 225 psi, no higher, and see if it stops the cycling problem. You still have a little too much refrigerant. Your first problem was probably due to getting the plates get too cold while running the 12-volt unit and that’s why the low pressure switch would not let the engine drive startup. It takes experience to know what to look for when reading a sight glass as each system is different. Your new high pressure setting of 225 psi is ok and you won’t need to let out any more refrigerant. Enjoy your cruise and find something else to worry about.

3. Question: We left the boat for a week with the Adler/Barbour refrigeration system running. When we returned everything was frozen and the compressor was still running. I had to turn thermostat off manually.

Answer: The Thermostats on these systems have open contacts and need cleaning and lubrication. Try using a tuner control spray cleaner & lubricant. These contacts switch
low power and only need cleaning. If the thermostat is mounted too close
to the evaporator moisture can freeze in it and cause it to stay closed. Thus, everything in the box gets frozen.

2. Question: My Adler/Barbour won’t start. It makes a chirping sound but that’s all.

Answer: There are some simple tests you can do before calling a service man.

Disconnect one of the fan wires, if the compressor runs the fan is defective change the fan.

Check the fuse located on module.

Disconnect the thermostat wires at the module and place a jumper across the terminals. Many times I find that a bad connection is causing a voltage drop when the unit tries to start. This unit will not run unless there are 12+ volts at the unit.

If no results after you have tried the above, the problem is either the electrical module or the compressor. DO NOT CONNECT VOLTAGE TO COMPRESSOR! IT IS NOT A MOTOR.

1. Question- a follow up to a previous correspondence: I checked the fan and the thermostat. I think that unit is ok, but the compressor is not running properly. When the compressor is trying to run, it draws 10 Amp during 2 seconds and after cut off during 20 seconds and begins again. Can you send me a drawing to check the compressor?
If it is possible can you send me the electronic diagram of the Danfoss box and the compressor? I don’t know why the compressor had 4 wires.

Answer: Ten amps on start up indicates a bad compressor. There is no repair for this type
problem. Inside the compressor there are two field coils that are energized alternately by the electronic unit to create rotation. A small third coil controls speed. Thus there are 4 terminals. The field coil insulation is bad on your unit or the rotating armature is stuck. A heavy tap with a hammer might break it loose, if not replace it.

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