RE: Adler Barbour No Start
There have been several changes over the years in the Danfoss compressors and their electronic controls, so when asking for help always report the compressor model. A large portion of my new book is dedicated to the Danfoss systems old and the new BD35 and BD50 models. I am assuming your AB was built prior to 1995 so I will list the no start troubleshooting procedures for the BD 2.5 and BD 3 compressors. • Danfoss BD 2.5 and BD 3 compressors failure to start. Repeated failure of start and a audible cycle beep is caused by a program in the electronic unit. It is programmed to stop the compressor if; #1. 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 the compressor electrical module. The wire size and polarity is important. #2. The fan or if water-cooled, the pump relay is drawing more than one amp.. To check disconnect one of the wires to fan. If the compressor starts OK replace fan. #3. 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 to 6 amps when running, if more than 7 amps, the compressor is about to fail. To do this test the unit must be running. It is sometimes possible with a failed compressor to see a quick movement of the ammeter to 10 amps. or higher. The best test to determine condition of the compressor field windings is to check their resistance with an ohmmeter, See Drawing. #4 It is a good idea to eliminate the thermostat as a cause while checking the system. To eliminate the thermostat and its wiring disconnect its wires from the electrical module. Place a place a jumper wire across the module thermostat terminals. #4. If the above checks do not determine the cause the electrical module is defective. WARNING, do not install a new module on a compressor that test bad with the ohm meter.
