Fridge -- danfoss compressor 3-blink code

[sailingharry]

As seen in the subject, I have a 3-blink code on a Danfoss compressor. Some background:


* I've owned the boat 2 years. However, since it was originally built as a spillover system, and a second system for the fridge was added, I don't know if it has always been broken and I just noticed it. My fridge is 45F, OK though I'd prefer 40.


* From a cold start, the compressor will run 10-20 minutes before it shuts down with 3-blink.


* The intake and outlet pipes never get cold/hot, respectively.


* When it shuts down, an infrared thermometer reads 110F on the compressor.


* I have removed the fan wires and jumpered the thermostat wires -- no change.


* I have not changed the power wires. However, they are fed from a 12V and Ground bus bar right at the batteries, using #8, for a 10' run. In addition, when off I have 13.5V at the compressor, and when running I have 13.2V -- so minimal drop (I am on shorepower with batteries in float). The batteries are 800Ah of AGM in good condition, so I am NOT pulling down battery voltage!



* I have done a resistance check on the compressor terminals, and it runs 2.5 to 2.8 Ohms -- about what they should be.


* A low-side gauge reads 55PSI when off, and it drops to 35PSI when it runs -- so clearly the compressor is doing SOMETHING. I will get high side pressures tomorrow.



* Once it throws the 3-blink code, it never recovers. It tries every 90 seconds for several minutes, then it runs for a minute or so, and throws the code again. I think (but didn't confirm) that the compressor temp continues to climb.


* In hopes of an easy fix, and knowing the sketchy nature of the control box, I put in a new one -- no change.



My gut is guessing a clog someplace (capillary tube?)-- it starts with no high side pressure, builds to refusal, binds the compressor, throws code, bleeds off, repeat. But that's a wild guess.


Anyone have experience with a compressor that throws the 3-blink after running for a few minutes (not at startup)?

[Richard Kollmann]

The three LED code is the electrical module detecting an electrical problem or mechanical problem in compressor if problem was mechanical it would be consistent problem. You eliminated high current draw of Fan. Low voltage to module generally a one LED flash code unless it is covered up by a quick second restart attempt then you would see a three flash code. The three LED code is a result of excessive or dirty amperage detected at module and not normal after the compressor has run foe several minutes.
When refrigerant flow is restricted in unit has correct amount of refrigerant it will not stop compressor with a 3 flash code.
I would recommend not using a voltmeter to detect the trouble. You have not told us the make and model of your unit except that with trouble LED installed it is most likely a BD 35 or BD50 compressor These compressors are pulse driven by three field coils and have been known to display conditions like you describe if amperage is not pure. Test #3 of my trouble shooting chart requires bypassing all of the boats electrical wiring an re-powering module with proper sized wire, fused polarity correct jumper wires from a fully charged battery. Now if system runs correctly you know where to look for the cause because it is not the refrigeration system.
Discard any foolishness that does not first troubleshooting with non destructive tests. This means tampering with refrigerant.

[OzeLouie]

Originally Posted by sailingharry

As seen in the subject, I have a 3-blink code on a Danfoss compressor. Some background:


* I've owned the boat 2 years. However, since it was originally built as a spillover system, and a second system for the fridge was added, I don't know if it has always been broken and I just noticed it. My fridge is 45F, OK though I'd prefer 40.


* From a cold start, the compressor will run 10-20 minutes before it shuts down with 3-blink.


* The intake and outlet pipes never get cold/hot, respectively.


* When it shuts down, an infrared thermometer reads 110F on the compressor.


* I have removed the fan wires and jumpered the thermostat wires -- no change.


* I have not changed the power wires. However, they are fed from a 12V and Ground bus bar right at the batteries, using #8, for a 10' run. In addition, when off I have 13.5V at the compressor, and when running I have 13.2V -- so minimal drop (I am on shorepower with batteries in float). The batteries are 800Ah of AGM in good condition, so I am NOT pulling down battery voltage!



* I have done a resistance check on the compressor terminals, and it runs 2.5 to 2.8 Ohms -- about what they should be.


* A low-side gauge reads 55PSI when off, and it drops to 35PSI when it runs -- so clearly the compressor is doing SOMETHING. I will get high side pressures tomorrow.



* Once it throws the 3-blink code, it never recovers. It tries every 90 seconds for several minutes, then it runs for a minute or so, and throws the code again. I think (but didn't confirm) that the compressor temp continues to climb.


* In hopes of an easy fix, and knowing the sketchy nature of the control box, I put in a new one -- no change.



My gut is guessing a clog someplace (capillary tube?)-- it starts with no high side pressure, builds to refusal, binds the compressor, throws code, bleeds off, repeat. But that's a wild guess.


Anyone have experience with a compressor that throws the 3-blink after running for a few minutes (not at startup)?

Hi Harry,
Your process of fault finding is spot on and in the correct sequence. Most likely you have a contaminated system that has now blocked.

Suggest you have the following evacuation and re-gas done:
First replace dryer with a proper FILTER dryer like the Sporlan 032 mounted vertically, exit downwards. If this can't be fitted in place of the old copper type, then simply leave the copper one in place and fit the proper filter dryer as well.
Unfortunately most small refrigeration systems are fitted with cheap 'spun copper dryers'. These items usually have no felt filter pad unlike the proper filter dryer type 032.

Copper spun dryers only have a screen. The screen doesn't collect the fine gunk that rubs off the desiccant beads or sludge that can form as a result of contaminated oil, eventually to possibly cause capillary or TX valve restriction.

For proper evacuation, if possible connect both your gauge suction line (blue) and high side (red) to evacuate system for several hours using a two stage pump and warming components. Once evacuation is complete, add refrigerant until there is an above zero PSIG gauge reading, close off red at gauge manifold, remove red high side hose charge from unit and continue to slowly top up system via suction (Blue) now with the unit running.
Only use pure refrigerant gas, usually R134a. When recharging, run the unit and only slowly allow refrigerant in sufficient to maintain a 12 - 14 PSIG suction. . Once this pressure is maintained without addition, close off and leave running. Fine tune later once temperature lowers and settles.

Do NOT use cans of R134a that contain dyes or sealants like those used on auto air conditioners.




​

[Richard Kollmann]

Report the high side pressure when compressor runs for several minutes. Did system ever run well? and Cool well? Do you know if unit was ever serviced with refrigerant? Is this an Adler Barbour or Isotherm unit?

[sailingharry]

Originally Posted by Richard Kollmann

The three LED code is the electrical module detecting an electrical problem or mechanical problem in compressor if problem was mechanical it would be consistent problem. You eliminated high current draw of Fan. Low voltage to module generally a one LED flash code unless it is covered up by a quick second restart attempt then you would see a three flash code. The three LED code is a result of excessive or dirty amperage detected at module and not normal after the compressor has run foe several minutes.
When refrigerant flow is restricted in unit has correct amount of refrigerant it will not stop compressor with a 3 flash code.
I would recommend not using a voltmeter to detect the trouble. You have not told us the make and model of your unit except that with trouble LED installed it is most likely a BD 35 or BD50 compressor These compressors are pulse driven by three field coils and have been known to display conditions like you describe if amperage is not pure. Test #3 of my trouble shooting chart requires bypassing all of the boats electrical wiring an re-powering module with proper sized wire, fused polarity correct jumper wires from a fully charged battery. Now if system runs correctly you know where to look for the cause because it is not the refrigeration system.
Discard any foolishness that does not first troubleshooting with non destructive tests. This means tampering with refrigerant.

Richard,


Yes, the make/model! Sorry. It is a SeaFrost, a BD35 (or 50), I'll check tomorrow.


I'm not sure how much closer I can get to "bypassing all the boats electrical." I come off a battery bus, the same bus that feeds my electric winches and inverter, and they both work fine. The bus feeds a small fuse block, that powers both the fridge and freezer -- and the freezer works fine. The power leads are #8, on a 10 foot run. I can move the power lead from the fuse block to the bus bar, bypassing the fuse, that might help. But remember, on a cold start it runs (vibrates, no led flash) for about 15 minutes, making power sound not an issue. I realize you dislike using a volt meter, but I mentioned that I have 13.2V at the control box terminals while running.


Assuming that when I move the wire to the bus bar, it continues to run for 10 minutes before tossing a 3-blink, what else should I check?

[sailingharry]

Originally Posted by Richard Kollmann

Report the high side pressure when compressor runs for several minutes. Did system ever run well? and Cool well? Do you know if unit was ever serviced with refrigerant? Is this an Adler Barbour or Isotherm unit?

This is the refrigerator side of a 2-unit system, both fridge and freezer. Since the freezer box does a fairly decent job of keeping the fridge cold (factory original, it was a single unit with spill-over), I don't know if it has ever really run right. Also, I've only owned it less than two years (and last year was a COVID year!), so I don't have much history on it.


I'll have high pressure readings tomorrow.

[sailingharry]

I should have mentioned my particular product. I have a SeaFrost. I do not see a drier of any sort.

Originally Posted by OzeLouie

Hi Harry,
Your process of fault finding is spot on and in the correct sequence. Most likely you have a contaminated system that has now blocked.

Suggest you have the following evacuation and re-gas done:
First replace dryer with a proper FILTER dryer like the Sporlan 032 mounted vertically, exit downwards. If this can't be fitted in place of the old copper type, then simply leave the copper one in place and fit the proper filter dryer as well.
Unfortunately most small refrigeration systems are fitted with cheap 'spun copper dryers'. These items usually have no felt filter pad unlike the proper filter dryer type 032.

Copper spun dryers only have a screen. The screen doesn't collect the fine gunk that rubs off the desiccant beads or sludge that can form as a result of contaminated oil, eventually to possibly cause capillary or TX valve restriction.

For proper evacuation, if possible connect both your gauge suction line (blue) and high side (red) to evacuate system for several hours using a two stage pump and warming components. Once evacuation is complete, add refrigerant until there is an above zero PSIG gauge reading, close off red at gauge manifold, remove red high side hose charge from unit and continue to slowly top up system via suction (Blue) now with the unit running.
Only use pure refrigerant gas, usually R134a. When recharging, run the unit and only slowly allow refrigerant in sufficient to maintain a 12 - 14 PSIG suction. . Once this pressure is maintained without addition, close off and leave running. Fine tune later once temperature lowers and settles.

Do NOT use cans of R134a that contain dyes or sealants like those used on auto air conditioners.




​

[Dsanduril]

I have no idea if Richard is correct (or Oze), not my area of expertise. But to test his hypothesis about dirty power unplug from shore power for a while and run strictly off battery. If it works then there’s an indication of a problem in the battery charger injecting too much ripple for the fridge controller. I’d probably clamp my DVM leads on at the fridge end at the same time and monitor voltage just to make sure there’s no connection heating voltage drop happening.

[Richard Kollmann]

That system uses I believe a different type of refrigerant control. It you can get a high pressure reading before it stops or an amp reading this might help in desiring between the two theories electrical or refrigerant flow.

Your guidance so far points to electrical wiring source. I new a repair man who carried a small motorcycle 12 volt battery to do this test. Ignore any advice about changing that units filter dryer.

[OzeLouie]

Originally Posted by Richard Kollmann

That system uses I believe a different type of refrigerant control. It you can get a high pressure reading before it stops or an amp reading this might help in desiring between the two theories electrical or refrigerant flow.

Your guidance so far points to electrical wiring source. I new a repair man who carried a small motorcycle 12 volt battery to do this test. Ignore any advice about changing that units filter dryer.

Assuming the fault finding process has dealt with power supply issues as OP previously suggested and the other symptoms described, then it is most likely that the system has a refrigerant or mechanical problem. The process I described before is the industry accepted method of dehydration and re-gassing.

Richard, I find it extraordinary that you advise against replacing the filter dryer!! NO system should ever be evacuated and re-gassed without a filter dryer change! (It's a bit like having a shower and putting your dirty undies back on: facepalm:

[sailingharry]

Off to the boat today, to get more data.


A question on the filter/dryer. The SeaFrost system doesn't mention (or sell) them. They do sell lots of other components -- TXV, tubing lengths, fittings, etc.


Does the SeaFrost system have a filter/dryer? Anywhere in the system?


The SeaFrost seems like a typical Danfoss based pre-engineered system, almost identical to the Frigibar on my old boat, and somehow they don't have that part. Come to think of it, I'm not sure residential fridges do either.....

[Richard Kollmann]

Originally Posted by OzeLouie

Assuming the fault finding process has dealt with power supply issues as OP previously suggested and the other symptoms described, then it is most likely that the system has a refrigerant or mechanical problem. The process I described before is the industry accepted method of dehydration and re-gassing.

Richard, I find it extraordinary that you advise against replacing the filter dryer!! NO system should ever be evacuated and re-gassed without a filter dryer change! (It's a bit like having a shower and putting your dirty undies back on: facepalm:

I know you recommend on your cabinet compressor units similar to this one needing repaired are returned to factory. This would not be easy done in this case. Standard practice I recommend is Dehydrating system and installing new larger flared filter dryer in a convent spot on line between condenser unit and evaporator. But first confirm any destructive methods are required.

[sainted]

You might try calling Cleave at SeaFrost. He designed the system you're working on, and he's very helpful.

The evaporator has an expansion valve on it. It may well be stuck or plugged.

I have two SeaFrost BDXP units, one for my fridge and one for my freezer. They've worked flawlessly for 12 years. Just sayin'

Scott

[wannacat]

If system was plugged the low side would go into vacuum and the hi side would go up. Then it wouldn't equalize and kick out on trying to restart as you've described. However, your not quite certain as to how it has run for the 2 years so I'm leaning towards an overcharge especially since it won't draw down below 35psi. The other explanation if compressor valves being bad. Get the head pressure and current draw as mentioned by others.

[sinnerman]

From the Danfoss guide 3 Blinks:

Motor start error
(The rotor is blocked or the differential pressure
in the refrigeration system is too high (>5 bar)).

Bad compressor

Too much gas

Filter / drier or the tiny capillary tube clogged.

One trick I read about is to run a hair drier (NOT a heat gun..!) over the Freon line starting at the in-fridge evaporator & back towards the compressor . It can sometimes free up a blocked capillary. (never tried it though..)

cheers