Frigoboat problem

[dstim]

Hi , my frigoboat (danfoss b50w keep cooled) freezer wont freeze any longer .
It sounds like the compressor only runs at low rpm and only drawing around 2-3 amps .
Any suggestions?
I don’t have the self diagnosing led , and I have a freezer full of food defrosting !

[Zanshin]

I feel for you, but without further information it won't be easy to diagnose and impossible to solve. Is it getting enough power (measure with a multimeter at the controller)? Any LED should work, you don't need to spend $10 for a $0.01 or less item.

If you feel the condenser plate in the fridge does it feel cold or warm or room temperature?

Odds are high that this will need repairing and won't be fixed on the fly. Those compressor units are built like a tank and if it is moving then it is probably working; so if there's no cooling happening it is from loss of coolant or perhaps blockage.

[Charlie-Bravo]

Stage one, get cooking to preserve some food.
next, fiddle furiously with the thermostat ……. a long shot but it could be a way to get life back into it.

If you can identify the thermostat connections/wire terminals you can bridge them to effectively remove the thermostat from the system, meaning when you switch it on ,  it starts and just keeps on running until your batteries are flat, or you turn it off. Worth a go just to rule out the thermostat, and it’s a start of the investigation .
Hope it’s not terminal.

Happy cooking

CB

[dstim]

Ok , so yes it gets cold , just not freezing.
I did bridge the terminals to rule out thermostat. It’s not that .
It runs , doesn’t seem to have enough rpm . I measured 12.93 v at the +,- terminals.
I took the small rpm “motherboard “ looking thing away completely and bridged the terminals. No dice . Still runs at low rpm and only draws 2-3 amps. At full rpm it should draw close to 6 amp right ?

[Zanshin]

The RPM is controlled by a resistor, see the manuals on my page at Miscellaneous Manuals

This is on the thermostat circuit and if the resistance is 0, then it will default to 2000RPM.

A 1.5K Ohm resistor will bring that up to the maximum of 3500RPM.

[dstim]

And now it works again … randomly. Did nothing other than sail for 5 hours , sit on the hook for 2hours then motor into the harbor….

[Charlie-Bravo]

Aah, so what have you cooked?

Good to know the thermostat is not the culprit, also a shame as it’s an easy replacement.

you say it is not running at the correct rpm, is it just a different noise …. if it were a mechanical seizure occurring you would expect high amperage and popping of fuses / breakers as it fights for life, so perhaps replacing the resistor is an option, they are generally a reliable thing the resistor, ( I’v cooked a few in my time) but perhaps the resistor that controls the rpm has gone dodgy, only replacing will tell , unless you can isolate it and measure its resistance with some accuracy.

The fact that it still chills things must be promising regarding refrigeration gas loss possibility, and it occasionally runs normally gives some potential for a fix.

You might be able, with careful study, to use a good multimeter to detect the led (that you don’t have) pulses ……. but they are jolly brief, ………. it may be worth robbing an led from some lesser used tech to determine the fault.

Hope you are eating well.

CB

[allegria]

I have experienced similar symptoms at the end of last year and I would second all the troubleshooting actions listed already, i.e. take the thermostat out of the picture, check the RPM resistor out, check the voltage, etc...

And I also agree the compressor itself is unlikely to be the culprit.

In the end, I had to get a new controller, which is relatively easy to replace if you find the right part.
Unfortunately, the controller cannot be repaired (not easily at least).

The fridge was working fine, then switch off for no apparent reason and the ice box would start defrosting, then it would start again, etc... the frequency of not cooling was increasing, until it gave up altogether.
My fridge had been running permanently for the last 12 years (shore power mostly!) without missing a beat...

It might be time to look for a controller as it will stop permanently at the most annoying time (just before the summer holiday for me!).

Cheers!

[loredo]

"And now it works again … randomly."

I've had a similar problem in the past.  The darn thing would run and maybe even work for a few days.  Then all of a sudden no joy, turn it off wait a bit and turn it back on and it started to work again... Doing the on/off thing worked for almost a year. At the end of  it would not get cold at all.  Here is what I observed (weird!).  Shut off the fridge / freezer then wait for an hour.  (That's to allow the coolant fluid pressure to equalize in the entire system.)  Now turn on the fridge and observe the amp meter.

Mine did this : it would pull it's normal 4A for a few minutes and then slowly the amps would go down to 1.5 maybe 2 .  All this in +/- 10 minutes. As the amps went down, no more cooling.  Very long story short, it was an obstructed capillary tube.  Once the compressor has pumped all the coolant fluid into the pipe before the capillary, there's nothing left to pump and the consumed energy (Amps) go down.  No joy here in repairs, the evaporator plate needed to be replaced. At that point I replaced everything, compressor, evaporator...