Three and Four pin Danfoss BD troubleshooting
If your refrigeration
unit is over 10 years old and has a Danfoss BD 2 or BD2.5 or BD3 compressor
then it has the older discontinued electronic 4 pin module.
Troubleshooting Danfoss compressors with 4 pin modules will consists of the following steps:
1. All of these compressors have a 4 pin module connector and their modules contain an external 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
3. Place jumper wire across thermostat terminals on electronic module, Compressor still does not run go 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 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. Small 12/24 volt boat refrigeration
using Danfoss compressors manufactured after 1996 will have a BD 35 or BD 50 variable speed compressor with a troubleshooting computer chip built into their control module. This circuit makes them easier to find troubled area if compressor fails to run. If your unit does not have this $2 LED install one, as it could save you a lot of money
later. Without the LED on these new units troubleshooting will be the same as earlier 4 pin Danfoss BD compressors.
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 a shipping
and handling charge of $20.
All of these systems using So called Danfoss or equivalent compressors require different troubleshooting methods so always report manufacturer of system and compressor model