Author Topic: Troubleshooting 12 volt Danfoss BD compressors.  (Read 32743 times)

Richard

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Troubleshooting 12 volt Danfoss BD compressors.
« on: May 10, 2012, 06:27:13 pm »
Troubleshooting 12 volt Danfoss BD compressors.
There are two different series of Danfoss BD 12 volt compressors the older fixed speed and the newer variable speed . If the refrigeration unit is over 10 years old and has a Danfoss BD 2 or BD2.5 or BD3 compressor then it has the older fixed speed discontinued electronic 4 pin module. Troubleshooting Danfoss compressors with 4 pin modules consists of the following steps:

1. All of these compressors have a 4 pin module connector and their modules contain a replaceable fuse. If this fuse is blown there are two reasons why either power wires to module are reversed or module has an internal failure.

2. Check to see that there is actually power at the refrigerator control module.

3. Place jumper wire across thermostat terminals on electronic module, Compressor still does not run go to next step.

4. Disconnect black fan wire from electronic module, Compressor runs, replace fan. Compressor still does not run after fan ground wire is disconnected, go to next step.

5. Run correct size fused and correct polarity jumper wires direct from a fully charged battery in order to bypass all boat’s wiring. Volt meter readings are of no value when looking for voltage spikes. Compressor still does not run electronic module needs to be removed and tested on another unit. If there are no other units available to test your module on I will test all 12 volt Danfoss control modules free except for BD80 compressor modules. Email me for shipping address and details.

Small 12/24 volt boat refrigeration units using Danfoss BD compressors manufactured after 1996 will have a BD 35 or BD 50 variable speed compressor with a troubleshooting computer chip built into control module. This circuit makes them easier to find troubled area if compressor fails to run. If this unit does not have this $2 LED install one. Without the LED on these new units troubleshooting will be the same as earlier 4 pin Danfoss BD compressors.

Trouble shooting LED will only flash if electronic module sees a compressor problem. In each case problems of compressor’s failures to run are identified by counting number of flashes of LED:
• No LED flashes would indicate either thermostat is open or no power to module.
• One LED flash and a 4 second pause indicates a non Danfoss wiring electrical resistance problem or low batteries. Because of module’s sensitiveity to milliseconds of a voltage spike they cannot be detected by a voltmeter. Solution is to bypass power wiring till resistance problem is located.
• Two LED flashes indicates fan over current cutout. If fan circuit on these variable speed compressors exceeds ½ amp compressor start up will be aborted. This condition can be confirmed by disconnecting Black fan wire at module, if compressor runs replace fan.
• Three LED flashes indicate excessive torque is required to start compressor. This is commonly caused by turning compressor off and back on too quickly or too much refrigerant or poor condenser cooling. Most people jump to the conclusion that there is a mechanical rotor lock up inside compressor and this is a mistake on Danfoss BD compressors.
• Four LED flashes indicate compressor motor not reaching sustained controlling speed above 1,850 rpm quick enough.

If someone has tampered with refrigerant by connecting gauges to a system letting air in or adding too much refrigerant can cause either a Three or Four LED flashing signal. On water cooled Danfoss condenser systems three and four LED signals are common when seawater gets into refrigerant circuit.
I closed my shop but after seeing what is being charged by boat refrigeration companies  who will test modules charging $50 and charging as high as $385 for new 4 pin modules, I decided to test and sell modules for a fraction of what is currently being charged.

If your shipping address is in the US   I will test your module on my Danfoss compressor refrigeration test stand.  This test stand will run at max compressor load for a one hour. I will then return your module to you for an insured shipping and handling charge of  $20.


Available New Non Danfoss 4 pin modules
Four pin modules for BD2.5 and BD3   twelve volt compressors only:
New module non Danfoss    $150 plus $15 insured shipping. Modules will only be shipped to addresses in the US.
I also sometimes have used 4 pin modules.


Because your unit is old and if it needs a new electronic module there is a risk that something is wrong that caused module to fail so most companies will refuse warranty of these modules. This is my electronic module warranty:

If any used module I sell fails to operate your unit it can be returned within 30 days for a full refund.
Any new module I sell can be returned for full credit within 30 days. Because of my own risk involved for the next 11 months I will return only 50% of the new units purchase price if module is returned within the first year.

Andrew10420

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #1 on: May 11, 2012, 01:25:04 pm »
Hi
We have just started to have a problem with our 12 year old Grunert fridge/freezer unit 12v.

Inside the freezer, half of the plate does not get any frost on it for the last 2 days. Previously the plate would frost over within a few hours of being defrosted. The compressor is working (It's hot) and the water pump has a good flow of water coming out.
If we have lost coolant from the unit how does one find the leak.
Thanks!

 

Richard

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #2 on: May 11, 2012, 03:33:37 pm »
Grunert has sold many types of 12 volt units describe your unit and the evaporator Plate. Is the compressor on your unit a Danfoss compressor with an electric module? How many amps is unit drawing?

Refrigerant leaks can be located with this method it you really have a leak:
A 50/50 mixture of liquid soap and water can local ½ ounce of refrigerant loss a year if properly used.  Using a one inch paint bush to apply soap mixture then stabbing suspect leak area until mixture looks like shaving cream breaks down surface tension of solution to metal forcing gas bubbles up through solution. A fast leak will quickly be visible slow leaks take several minutes to confirm location.

Andrew10420

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #3 on: May 16, 2012, 08:38:46 am »
Richard
We attach photo's of compressor and plate. We have also had to replace 2 (TWO) control modules (Yes $300 + for each) and I would like to send them to you for testing.

If I don't know where to start looking for a leak ........ where do you recommend.

Thanks for info so far.

Richard

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #4 on: May 16, 2012, 09:49:08 am »
I can not be sure this unit has a danfoss compressor without a picture of module or a module part number. Grunert sold a 12 volt model called Polar Mate with an unknown compressor even to Grunert its unknown.

I can only test Danfoss modules. If we confirm they are Danfoss modules email me for shipping details.

Andrew10420

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #5 on: May 16, 2012, 11:41:41 am »
The control modules are Danfoss 101N0210.

My email is Andrew_Benjamin@msn.com

Do I send $40 with the units? and I do want the units back since they have worked for a few days whilst we have been waiting for a new replacement.

   

bcares

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #6 on: May 29, 2012, 04:17:08 pm »
I have a 1994 sailboat with Adler-Barbour refrigeration that I have had to get recharged each spring because of a leak. According to a local refrigeration tech, the system works fine until its shut off for the winter and then the refrigerant slowly leaks out. I really didn't mind paying a service fee once a year rather than tearing everything out to find the leak. Last year, the unit suddenly stopped working. The fan would run and the compressor would kick in for a few seconds (5 or 6), then an audible beep, then it would quit. Thirty seconds or so later, it would run through the process again. The tech replaced the compressor/condenser/fan unit with a used one and everything started working again for the rest of last season. This year, the replacement unit is doing exactly the same thing. Should I have the module tested or just give in and make an anchor of the whole thing and start fresh?!! Thank you.

Richard

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Re: Troubleshooting 12 volt Danfoss BD compressors.
« Reply #7 on: March 30, 2014, 11:35:14 am »

Because your unit is probably built before 1996 it will have a fixed speed BD2.5 or BD3 compressor. The electronic beep is letting you know that voltage or amperage is not correct and module prevents compressor from running. If you will send number on module or picture of it I can confirm what trouble shooting procedures to send you.

I would defiantly recommend you repair unit yourself worst case cost zero to $150.