BD50F compressor problem

[rawlie]

Hi, new here and looking for advice on our fridge system that's stopped working. It is an Adler Barbour air & water cooled system with a BD50F Danfoss compressor. The system starts up and the compressor briefly starts and then stops. I've changed the control unit and that did not help. Any ideas on what other diagnostics to try and isolate the problem? For info, a while ago I removed the diagnostic unit and hard wired it with a sensible relay and fuse.

[rawlie]

Originally Posted by rawlie

Hi, new here and looking for advice on our fridge system that's stopped working. It is an Adler Barbour air & water cooled system with a BD50F Danfoss compressor. The system starts up and the compressor briefly starts and then stops. I've changed the control unit and that did not help. Any ideas on what other diagnostics to try and isolate the problem? For info, a while ago I removed the diagnostic unit and hard wired it with a sensible relay and fuse.

Update. Found that by shorting the stat at the control box it ran fine. Lashed an external stat by control box and it ran fine! Therefore must be stat wiring or connector at fault. Easier to check connectors than rewrite and found a 1.5k resistor in the stat circuit, removed this and it ran fine! Since researched and somehow this controls the compressor speed. By removing it it runs at its slowest 2K rpm. Any thoughts on why removing it has made the system work ? Also anyone know the value of resistors to get different speeds?