3 flashes on Danfoss control

[TBo]

Hi all,
I’m bouncing that thread again as it seems a good repository on the subject.

I currently have the 3 flashes code on my danfoss BD50F compressor (part of a 24V watercooled frigoboat fridge /freezer from 2009 with a 101N0210 controller, installed by the boatyard).

I’ve read the previous entries and they are very educational but my situation seems a bit different:

From a base case where the fridge has been off for days, when I start it, it runs, cools down and stops when it reaches the desired temp. It then slowly warms up and when the thermostat triggers, the compressor starts for 2s, stops and displays 3 flashes. The same restart/fail/flash cycle repeats every 30s or so.

But, if i switch off the power and wait long enough (a few hours), then the [start, cool down, stop, warm up, {restart, run 2s, fail, wait 30s, repeat}] cycle works. I’ve been able to do that many times.

To me, and without further testing, that tells me the compressor is ok, the controller is ok, the electrical parts are ok.

The system refrigerant load has apparently never been changed (not during my 6year ownership, and probably never judging by the cover on the service valve).

What exactly could cause that failure to subsequently cool again after the initial cool down?

Thanks for your insights

Tom

[SV THIRD DAY]

It happens all the time....
A unit running creating heat and load uses more amps...the amps either cause the failing controller to fail OR most likely result in a voltage drop that is knocking out the controller.

Do the Electrical tests this smart guy talks about in his electrical troubleshooting videos:

https://www.youtube.com/watch?v=r9FoE1uHzy8

The electrical tests are the same for all danfoss compressors.

Cheers

[GordMay]

Greetings and welcome aboard the CF, Tom.

[dav31195]

Good morning,

After many years, my refrigerator has stopped working.
I then replaced the danfoss 101n210 control unit with the 212 version, as the 210 is now out of production.
I also replaced the thermostat.

The fridge started correctly and ran for a whole day. At some point, however, it shut down and did not start again. I called a technician who charged the fridge and then checked that all the parts were OK and told me that the problem could only be the controller. I tried changing the controller and also a new thermostat, but nothing, the problem still exists.

What could it be? Why did it work for a day when the controller was replaced and then never started again?

In my case the controller also flashes three times.

Thank you for all the support

[DeBe]

Had a compressor that would not start, & the winding resistance was not right on one of them. Cut the compressor apart & found the shorting link on the center of the star winding was a poor conection. On removing the link & refitting the compressor would now run. It did satisfy my curiosity. as to why??

[SoggyPaws]

One of the best sources of Danfoss compressor troubleshooting this page on Coastal Climate Control's website. They have a really good 1-page PDF flow chart that helps you figure out where in the system your issue might lie. (Videos too, if you are into Youtube).

https://coastalclimatecontrol.com/re...roubleshooting

It's specifically for Frigoboat units, but that's just a standard Danfoss system with a little passive cooling built in.

[OldGreyB]

Oze Pete,
THANKS!

The post #9 on this thread in 19-09-2017 worked a treat today for me. It required #5. Replace Electronic unit.

But I had a spare unit from a fortuitous gifting a year ago from another cruiser doing a fridge upgrade. Now the Admiral is very happy again.

Best Regards
OldGreyB