Fans not running on frigoboat/danf

[YoloSF]

Hello,

I have a Danfoss bd35 system and I'm having some overheating on one of the compressors overheating. I have disconnected every wire and reconnected them cleaning up some corrosion and I'm getting 12.4v at minimum (I'm cruising on the hook in Fiji so not plugged into shore). I have disconnected the fans and they work with a battery, but they don't run when they're hooked onto the refrigeration system. One of the fans (a big one) is running, but not the small ones. I'm really stuck here, I'm not sure what else to do to troubleshoot.

The fridge is cool and works fine, but I'm concerned about the overheating on the compressor and it's VERY HOT, as in it'll burn you if you touch it... I suspect I have more problems down the line but I'd like to figure out the fans first. Any tips?

Thanks

[jamhass]

1. Pull the fans and make sure they are working when powered from a known good 12v source.

2. If bad, replace

3. If good, check the fan terminals on the controller for 12v to the fan

4. If no 12v for fan, likely need to replace the controller, or power the fan from the compressor 12v.

Curious, where are the fans located? In our system we have 1 6-inch fan cooling the compressor, and 1 2-inch fan controlling spillover between freezer and refer. And yes, even with the fan running, the compressor does get warm, but the controller board does stay cool.

[Richard Kollmann]

Electric compressors can be damaged if over heated so Danfoss BD compressor electronic control modules are have several safety circuits to protect Compressor.
The BD35 module provides power to the cooling fan from wire terminals Small + and F terminal. This circuit if exposed to fan current exceeding 500 Milliamps (1/2 amp) will prevent compressor from running indicating poor system cooling.These muffin fans each have several transistors inside and bearings can run dry of lubricant at near 4000 operating hours. Air-cooled Systems powered by Fan cooled Danfoss compressors can experience a 30 year trouble free like with the one exception fan failures.

If you must run two fans suggest you use a relay.