Fridge Failure - Danfoss BD35F motor start failure

[hpeer]

Richard,

I get everything you are saying.

From my personal point of view, especially if cruising for any extended period of time, one should carry a spare controller. Then it’s pretty easy to swap out one controller for another and do some simple trouble shooting. For me that’s a whole lot easier than running a parallel cable set up.

If that quick check doesn’t work then I would go your process. Different boats with different accessibility may have different answers.

BTW, with regards to leaks, I developed a leak that was hard to find. It was in the tubing INSIDE the reefer WALL. Just in a straight piece of tubing between the inside and outside of the reefer. I only found it when I determined “the hell with it” and removed the plate. When I pulled the tubing out it almost fell apart. Perhaps a bad initial installation? Surely not a common problem but very frustrating.

[cgebluewater]

Gentlemen,
I am now on the boat and this is what I have so far.
1. Check all fittings for leaks, foamed them up good several times, no leaks both running and not running
2. on startup ammeter showed 6.8 amps then gradually went down to 3.6 amps and stays steady at 3.6
3. AB "power plate" holding plate cooling down a bit but not what I would call cold after about 2 hours. cold line is condensating. Still staying on without stopping or any error codes.
4. I can hear a very slight hissing sound coming from the cold plate.
5. cooling fan working good.
6. ambient temp is about 74 degrees in the boat. Cold machine is in large engine room with doors open and temp also about 74 degrees.
7. Have not gone shopping yet so no food or drinks in 6 (+ or -) cubic foot box
I put a jumper at the thermostat to bypass it. left the resister in place but I don't know how many ohms it is

Any thoughts or suggestions ? should it take over night of running steady to bring down the temp in the cold signifacatly ?

Any advise is much appreciated. Thank you in advance

[OzePete]

Originally Posted by cgebluewater

Gentlemen,
I am now on the boat and this is what I have so far.
1. Check all fittings for leaks, foamed them up good several times, no leaks both running and not running That is a good start
2. on startup ammeter showed 6.8 amps then gradually went down to 3.6 amps and stays steady at 3.6 Being a BD35 it is working to be drawing 3.6a
3. AB "power plate" holding plate cooling down a bit but not what I would call cold after about 2 hours. cold line is condensating. This may be the clue!!
You say sweating (condensating). If it is the suction pipe (The one that runs back to the compressor) and it is sweating yet the eutectic plate is not near temperature, then the system has way too much gas in it. Suggest purging out some gas while running but only in small amounts say depress the Schradar valve for say 4 seconds then leave running and repeat in 20 minutes if the suction line remains sweaty. You may have to do this many times but allow 20 minutes run between each purging and only purge if that suction pipe is refrigerating (very cold) Still staying on without stopping or any error codes.
4. I can hear a very slight hissing sound coming from the cold plate.
5. cooling fan working good.
6. ambient temp is about 74 degrees in the boat. Cold machine is in large engine room with doors open and temp also about 74 degrees.
7. Have not gone shopping yet so no food or drinks in 6 (+ or -) cubic foot box
I put a jumper at the thermostat to bypass it. left the resister in place but I don't know how many ohms it is

Any thoughts or suggestions ? should it take over night of running steady to bring down the temp in the cold signifacatly ?

Any advise is much appreciated. Thank you in advance

Do as suggested and you should have cold beer tomorrow!

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[Richard Kollmann]

Pete, Telling this boater to let out refrigerant is like telling him to shoot himself in the foot to create greater pain. Did you not read the BD35 at sustained running speed was drawing 3.6 amps.

[OzePete]

Originally Posted by Richard Kollmann

Pete, Telling this boater to let out refrigerant is like telling him to shoot himself in the foot to create greater pain. Did you not read the BD35 at sustained running speed was drawing 3.6 amps.

Richard I read that the consumption rate was initially 6.8A reducing gradually to 3.6A.

I also read that the suction line was refrigerating / sweating, which can only occur if that capillary system is over charged with refrigerant. The ONLY cause of that suction line sweating is that refrigerant is evaporating in the suction line in other words... TOO MUCH refrigerant, period!
Or perhaps Richard, you can please advise us how the suction line can show signs of evaporation occurring, other than being over charged with refrigerant?

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[Richard Kollmann]

Pete, cold beer tomorrow? Probably not.

Reported Facts.
2. on startup ammeter showed 6.8 amps then gradually went down to 3.6 amps and stays steady at 3.6
3. AB "power plate" holding plate cooling down a bit but not what I would call cold after about 2 hours. cold line is condensating. Still staying on without stopping or any error codes.
4. I can hear a very slight hissing sound coming from the cold plate.

Pete, Letting out some refrigerant is not going to provide very cold beer tomorrow based on the facts you were given on this forum.
2.Compressor starting amps are almost always higher than then they eventually stabilize at after a 10 minute pump down.
3. This is not a standard evaporator or a holdover plate it is an Adler Barbour power plate after compressor run two hours. Temperature off plate line had cold condensation only.
4. A very slight hissing sound coming from power plate.

(Or perhaps Richard, you can please advise us how the suction line can show signs of evaporation occurring, other than being over charged with refrigerant? ) Pete Glad to help, I will again try to De Bunk your suggestion to remove some refrigerant.

The amperage of 3.6 amps is not enough to support a too much refrigerant theory. Would not the amperage be higher if there was too much refrigerant in system? And if too much refrigerant was the problem why wasn’t there a LED code signal?

The slight hissing sound can be interpreted as not enough refrigerant or with Superman’s eyes you might be able to determine there is too much refrigerant. Yes, there are techs who claim they can tell when refrigerant charge is correct but I also question that theory.

I believe there are two probable causes of this systems poor performance:

Low on refrigerant.

Moisture in refrigerant? The hissing sound in power plate if steady for more than 20 minutes without interruption and no pauses long enough to allow ice to melt and reform in capillary tube. The melting and freezing will act as a 33 degree thermostat producing only cold condensation on plate and line but no frost.

[cgebluewater]

Guys here is an update,
Since I brought new ones with me I decided to replace the fan and module, I figured "what do I have to loose". When I installed the new module I disconnected the AB board and added an LED I brought with me and added it directly to the module. As an FYI the AB board did have some burn marks !

So now I have clean 12 volt power connected directly with a short run of new 10 awg wire to a good battery with only a new 15 amp fuse at the positive battery terminal.
New module & fan & LED.
Drawing 3.3 amps and now hearing what sounds like a very quite water fall flowing down inside the AB power plate instead of the hissing sound. Still condensation on what I assume is the return line. One odd thing, both copper lines are the same size in the box, about 3/8 but one reduces to a slightly smaller size somewhere hidden that I cannot see the reducer because all the line that I can see is the two slightly different sizes including where it connects to the cold machine, (except in the box).

This is as far as I have gone at this point.

Any thoughts ?

[cgebluewater]

One other thing I want to mention. I am still not sure which line is the low pressure side since they are both the same size in the box, about 3/8", one is dry and not hot or cold, the other is cool & condensating. The other end at the cold plate one line is about 3/8" and the other is slightly smaller, maybe 1/4 ". All lines coming in and out of the cold machine and coming in and out of the compressor, condensor,dryer, etc. feel neither hot or cold.

Can one of you describe in some detail which would be the " low pressure" line and which would be the "high pressure" line at the "cold machine".
The smaller 1/4 " line would be ??
The larger 3/8" line would be ??

The larger 3'8" line goes right into the compressor. The line coming out of the compressor (smaller line maybe 1/4" line)goes into the condenser then comes out of the condesor through copper water cooling loop then through the dryer and out to the smaller 1/4" line that goes to power plate.

Thanks I really appreciate the help

[hpeer]

Starting at the output of the COMPRESSOR, it compresses the refrigerant. Because it is compressed it requires a little tube. It goes to the plate where it is allowed to expand. When it expands it sucks up heat/cools the plates. It is now NOT compressed and bigger so it returns to the compressor to get compressed once again.

I omitted a fair bit to keep it super simple.
Compressed is smaller.
Return is bigger.

[cgebluewater]

So it would seem the small copper line should go all the way to holding plate but on mine somewhere between the cold machine and the holding plate it increases to both lines being the same size inside the box to and from the cold plate.
At is point I’m out of options so maybe I should bleed off some refrigerant hoping that it is overcharged. I assume I should bleed it off from the large line at the cold Machine not the small line, is that correct ?

[hpeer]

If you want my advice I think it’s time you called in an expert.

My strong suggestion is that you get a good qualified technician who can do the whole evacuate and dry routine. Make sure you have no water in the system. Install a dryer in the line. And recharge the system with the correct amount of Refridgerant.

This is gonna cost a couple of hundred bucks because it takes the guy over half a day if done correctly. He isn’t doing much most of the time but you are paying for his time. And good guys are not cheap.

Be ther, use the time to chat with him, consider it a crash course on refridgeration. Money well spent.

Hopefully that will resolve all your problems and if not you will have a much better idea of where you stand.

I went pretty much the same route as you. Drove myself crazy. Had a couple of half baked techs, weren’t much help. Once the above procedure was correctly done things went much better. This year I had two problems. A bad controller and a little low on refridgerant. But I was able to diagnose them much more simply and knew how to add just the amount of refridgerant needed, no more.

Tell us where you are and maybe someone can make a recommendation. If not either call you units distributor or call Frigoboat. They may be able to recommend someone local.

Anyway that’s my advice. Worth every penny you paid.

[OzePete]

Originally Posted by cgebluewater

So it would seem the small copper line should go all the way to holding plate but on mine somewhere between the cold machine and the holding plate it increases to both lines being the same size inside the box to and from the cold plate.
At is point I’m out of options so maybe I should bleed off some refrigerant hoping that it is overcharged. I assume I should bleed it off from the large line at the cold Machine not the small line, is that correct ?

Just let some gas out of the suction for short 4 second bursts while running and repeat after 20 minutes until the suction line stops sweating. Maybe many times
If your suction line is refrigerating it is overcharged.

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[Emmalina]

Seem to be drifting of thread here a little. Guess what I have just had the 3 flashes of death myself... Been going on a while but yesterday I has given up trying ! So swaped the module and hey presto ! 3rd one in 6 years. Great units when they work but those modules are &*()#@

[Richard Kollmann]

Danfoss engineering has an excellent track record when their unit's are installed correctly. A failure while under warren-tee is always a possibility. repeated failures would indicate there is a condition that is causing failures that should be corrected. I have received many modules to test that have been in service for 20 to 30 years. All electronics can be damaged by dirty electrical power and power overloads. The two main causes of module failures are electrical power source is not from main battery buss and excessive module and compressor heat.

[Emmalina]

I would agree with you Richard but having 2 units side by side arriving pre gassed and installed in 2 identical boxes. Seems strange one gives trouble and the other never !