Waeco Adler Barbor Thermostat

[Celestialsailor]

I have installed my cold machine on my boat. The unit is unused but had been stored on my previous boat for around 5 years. Hooking it up I got nothing. Finding a trouble shooting guide on line, it took me step by step to diagnose it. First I had power from the PC board to the Yellow (-) and Red (+) on the Module. Then they recommended removing the black and brown wires from the Module and jump across the two now exposed terminals...Voila!...it turned on. It suggests that this mean it is either the phone jack connection. (why they use this, I'll never know) or the analog thermostat itself. The only thing I had to do the the thermostat sensor was to bend it in the shape of a "J" and fasten it to the evaporator. So maybe this damages it...I don't know.
My next course is to eliminate the phone jack connection and use a mini terminal connector.
My question is...has anyone had this problem? If it is the thermostat, who carries them and do I have to buy theirs or can I go to an appliance supply outlet and get one?

[Richard Kollmann]

In the mid 90s someone decided to upgrade design of Adler Barbour’s famous Cold Machine by adding extra features expanding both the Cold and Super Cold machines. On all earlier Cold Machines to add a fan or water pump it was necessary to add a relay. The Super Cold machine’s higher output with internal brush motor compressors and their wiring terminal strip were not as dependable as the much simpler Cold Machine. Electronic thermostats were impressive to gadget lovers with money but not simple enough to install on older units.



Adler Barbour upgraded and standardizes both the new CU 100 and CU200 machines the same except the CU200 would be equipped with a small inexpensive water cooler tube condenser installed after air-cooled condenser. Both Adler Barbour units now use the same variable speed Danfoss BD50 compressor and an add on Stainless Steel troublesome wiring box containing:

• A main 15 amp fuse
• A 5 amp Danfoss Fan/pump control circuit fuse
• Trouble shooting LED
• An external accessory relay
• A standard four pin telephone phone jack to accommodate either a standard thermostat or the pre-wired electronic thermostat.

To test thermostat and its wiring turn knob to any number and check continuity at phone plug back through thermostat, You should read resistance of speed resistor if circuit is open replace thermostat. www.rparts.com Stocks Evaporator temperature controlled replacement refrigerator thermostats.

If thermostat tests good My recommendation is to cut the mail jack plug off thermostat wire. Connect the two actual thermostat wires direct to Danfoss control module terminals C and T removing wires there now. The information I have is the standard mechanical thermostat wires used in phone cord are Yellow and Green to be connected to Terminals module terminals C and T.

The current in thermostat circuit is from one milliamp to five milliamps depending on size of compressor speed resistor instilled in wire near thermostat. With thermostat bypassed the way you tested it without resistor in jumper wire compressor was running at minimum speed 2000 rpm.

[Celestialsailor]

Hi Richard...I was hoping you would chime in. Thank you for the input and the Rparts recommendation. I see they have 3 available...Freezer - Service Pack (Thermostat) Cooler - Service Pack (Thermostat) and Refrigerator - Service Pack (Thermostat)
I'm assuming it would be the Freezer thermostat I would need since the original AB one is clamped to the evaporator unit.
As far as testing the variable resistance from the plug to the exsisting thermostat. It seems silly to me that they use a phone jack for the purpose. I will cut the plug off to test it anyways. Does not seem like a really good connection. Has this been an ongoing issue with these?

[Richard Kollmann]

You would want a refrigerator thermostat for a evaporator temperature of +35 to -13.

You do not need to cut plug off to ohmmeter test for open wiring or thermostat contacts.

Corrosion of electrical board in stainless box has been a problem for boaters not phone plug. New units are provided with a paste to protect phone jack plug.

[Celestialsailor]

Ok, thanx. I will try the test this week coming and report back.

[Celestialsailor]

Just back from the boat. Here is how I proceeded. For the convenience of doing measurements from the wires (yellow and green) at the phone jack, I eliminated the jack all together. Next I disconnected the the wires at the thermostat. I checked for continuity. Green wire good. Yellow wire, open. I noticed the yellow connector was covered with longer than normal shrink tube. I cut it open and found a 270 ohm resistor (see attachment). I disconnected the resistor from the wire and had tone back to the jack end. Then checked the resistor...dead!.
Richard...If you're still around, what does this resistor do? Speed control perhaps? I connected everything back up (minus the resistor) and voila...it runs. The box went from 80F to 28 at the freezer in 45 minutes. The first hour cycled on for 7 minutes and off for 5 minutes. After 5 hours it cycled on for 4 minutes and off for 8 minutes. Then the freezer is 22F and box 38F. This was on the #2 setting on the thermostat. I had a couple of warm blue ice packs and some bottled water for load. To me, it is performing well.

[msanderson]

Originally Posted by Celestialsailor

Just back from the boat. Here is how I proceeded. For the convenience of doing measurements from the wires (yellow and green) at the phone jack, I eliminated the jack all together. Next I disconnected the the wires at the thermostat. I checked for continuity. Green wire good. Yellow wire, open. I noticed the yellow connector was covered with longer than normal shrink tube. I cut it open and found a 270 ohm resistor (see attachment). I disconnected the resistor from the wire and had tone back to the jack end. Then checked the resistor...dead!.
Richard...If you're still around, what does this resistor do? Speed control perhaps? I connected everything back up (minus the resistor) and voila...it runs. The box went from 80F to 28 at the freezer in 45 minutes. The first hour cycled on for 7 minutes and off for 5 minutes. After 5 hours it cycled on for 4 minutes and off for 8 minutes. Then the freezer is 22F and box 38F. This was on the #2 setting on the thermostat. I had a couple of warm blue ice packs and some bottled water for load. To me, it is performing well.

Hi, I'm running through a similar project. I had to replace an old AB condenser with the updated model CU200 super cold machine.

The 270 Ohm resistor sets the speed of the compressor. In that case, 2,500 rpm (the speeds are shown on the second page of this document: http://www.sustainablechoice.net/pdf...ssor_Specs.pdf

In my case, even though my thermostat measures open circuit, things are actually working for me ... though I think that it is probably working at 2,000rpm rather than 3,500 rpm (which would require a 1,500 Ohm resistor) which I think would be better for the cold plate I have.

I can't tell from the "RParts" page whether their thermostats come with a resistor installed or if I'll need to add one myself.

Have you been successful with your project?

Cheers,
Mike

[Richard Kollmann]

In mobile refrigeration’s ambient air and water temperatures are not as stable as a fixed home refrigerator’s environment. Another problem with boat icebox conversion refrigeration is compressor may not be sized to match each box’s heat load. Older Danfoss BD2.5 and BD3 fixed speed compressors rarely matched a icebox’s heat load. Danfoss new variable speed compressors BD35 and BD50 can be adjusted manually or automatically lowering speed to achieve a more energy efficient speed or by increasing speed so that desired box temperature can be achieved and maintained. The problem is the higher Rpm mean poor daily energy efficiency especially if evaporator can not handle thermo heat exchange based on capacity of compressor.

If you study Danfoss’s BD50 compressor application spec chart, http://www.sustainablechoice.net/pdf...ssor_Specs.pdf, page two how Rpm affects capacity output and how it also affects compressors Coefficient Of Performance (COP). At minimum speed of 2000 rpm Danfoss variable speed compressor has the highest and best COP.

To control BD35 and BD50 compressor speed, resistance of thermostat’s wiring is increased from zero resistance producing 5 milliamps of current to control module and producing 2000 rpm. When adding a 1500 ohm ¼ watt resistor milliamps drop to 2 milliamp and compressor speed increases to max speed of 3500 rpm. The trick is to find a compressor speed anywhere in between that uses the least daily amp-hrs and still maintains desired sustained box temperature.

The simple rule if you do not have a daily amp-hr meter is, Run compressor at the slowest speed that maintains desired box temperature and compressor runs less than 50% of the time. When you purchase an Adler Barbour system or just the evaporator separately there will be a tiny resistor in thermostat wire near thermostat that should provide correct compressor speed for that size evaporator. Thermostats themselves do not come with speed resistors. Danfoss AEO module does a great job of controlling compressor speed adjusting compressor as load conditions change much like automatic transmissions do on an automobile.

If you use any device to increase compressor speed Remember foot note on Danfoss spec sheet (FAN COOLING OF ELECTRONIC UNIT COMPULSORY). These electrical modules are designed to be cooled by air from condenser fan but as Btu capacity is increased to high output Danfoss requires additional cooling. One advantage of the AEO is it incorporates its own fan.