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Matt Johnson · 17-12-2012, 21:48

I'm having an issue with my Grunert refrigeration system where the compressor takes a few try to start properly. Eventually the compressor does work and my box is always been cool, but I'm sure this will eventually lead to a total failure and would like to fix it while I'm still in the states.

The fridge uses a Danfoss D35F compressor and the diagnostic LED on the 101n0200 module flashes three times which indicates a rotor is blocked or refrigeration system is too high per the manual. Unfortunately, I'm not sure what that means and it seems the expert's forum is down (Richard Kollmann). From what I can gather on Google, there is a likelihood that it's the fan or module that is bad. I tried disconnecting the fans ground to see if that helped, but it doesn't effect the compressor working or not (still get the flashing three LED).

I can get a 101N220 module from Sailor's Exchange which is right down the street from where I am, but don't want to spend the $200 to try it if this isn't the direction I should be looking. Anyone have any ideas what the three LED flashes mean or why my compressor starts only some of the times?

Thanks for the help,

Matt

**atoll** · 18-12-2012, 00:19

low voltage from too small wire size or corroded connections will cause this problem.

Richard Kollmann · 18-12-2012, 05:39

I do not understand why my forum is up and down so often. Has anyone tried to connect gauges to your system or added refrigerant? Second question has anyone tried to connect 12 volts direct to compressor pins, this would have destroyed compressor? Three LED flashes indicates an overload condition, if answer to these questions are NO then module should be tested and if bad replaced. I test Danfoss three and four pin modules you pay only shipping. I also now sell both type non Danfoss modules for $150. Modules I sell are guaranteed to operate your unit even if bad compressor destroys new module I do not believe anyone else offers this guarantee. If you are interested PM me for details.

Matt Johnson · 18-12-2012, 08:48

Quote:

Originally Posted by Richard Kollmann

I do not understand why my forum is up and down so often. Has anyone tried to connect gauges to your system or added refrigerant? Second question has anyone tried to connect 12 volts direct to compressor pins, this would have destroyed compressor? Three LED flashes indicates an overload condition, if answer to these questions are NO then module should be tested and if bad replaced. I test Danfoss three and four pin modules you pay only shipping. I also now sell both type non Danfoss modules for $150. Modules I sell are guaranteed to operate your unit even if bad compressor destroys new module I do not believe anyone else offers this guarantee. . . .

Unfortunately, nobody has touched the unit in at least the 4 years I have owned the boat. Do you think Atolls suggestion that it's low voltage could be the issue? It seems whoever installed the system only ran 12/2 AWG to the panel about 10 feet away.

Thanks,

Matt

**atoll** · 18-12-2012, 08:58

Quote:

Originally Posted by funjohnson

Unfortunately, nobody has touched the unit in at least the 4 years I have owned the boat. Do you think Atolls suggestion that it's low voltage could be the issue? It seems whoever installed the system only ran 12/2 AWG to the panel about 10 feet away.

Thanks,

Matt

awg 12 or 4mm2 wire sounds about right for a 10 ft run,i have the same danfoss unit and it is very sensative to low voltage.
my advice would be to clean all the contacts and check the wire is not corroded and see if it works better before changing control modules.

**sailorchic34** · 18-12-2012, 09:10

Boat wiring is just like the wiring in LBC's, or little british cars with lucas electrics. The connectors are aluminum and the wire is copper. After a few years you get enough galvanic corrosion between the ring or spade connector and wire to cause a voltage / current drop.

The fix for many power / wiring issues in both boats and LBC's is to cut and replace the connector. Amazing how often that fixes a problem...

You can also measure the voltage at the power pins on the control module which should be just about the same as at the panel. Any more then 0.1 to 0.2V voltage drop would indicate a bad connection / wire.

**atoll** · 18-12-2012, 09:20

Quote:

Originally Posted by sailorchic34

Boat wiring is just like the wiring in LBC's, or little british cars with lucas electrics. The connectors are aluminum and the wire is copper. After a few years you get enough galvanic corrosion between the ring or spade connector and wire to cause a voltage / current drop.

The fix for many power / wiring issues in both boats and LBC's is to cut and replace the connector. Amazing how often that fixes a problem...

You can also measure the voltage at the power pins on the control module which should be just about the same as at the panel. Any more then 0.1 to 0.2V voltage drop would indicate a bad connection / wire.

+1

senormechanico · 18-12-2012, 09:50

Wires to the panel? Then where, and in what condition are the feed wires?
Battery condition?

You could have one or all of the above contributing to your problem.

Grab a decent digital voltmeter and test the input connections of the fridge AT THE FRIDGE during startup.
I'll bet the voltage sags significantly.
If it goes below 11 volts, there's your problem.

**atoll** · 18-12-2012, 10:09

Quote:

Originally Posted by senormechanico

Wires to the panel? Then where, and in what condition are the feed wires?
Battery condition?

You could have one or all of the above contributing to your problem.

Grab a decent digital voltmeter and test the input connections of the fridge AT THE FRIDGE during startup.
I'll bet the voltage sags significantly.
If it goes below 11 volts, there's your problem.

i may not be correct but i think the module is designed to cut out at 11.8 volts to protect the batteries.

the po of my fridge had this/ your problem till he upped the wire size

Matt Johnson · 18-12-2012, 10:43

Well, I ran a 8/2 wire 8' from the fully charged battery bank to the control module on the fridge and I'm still getting the blinking light. To me it seems that the fridge is running, turns off, then tries to turn back on too soon. All in all, it's off for under 2 minutes before it tries to cycle back on. Is this too soon? Temperature in the boat is 75 degrees right now, but this does it when it drops into the lower 50s during the night too.

**atoll** · 18-12-2012, 11:05

Quote:

Originally Posted by funjohnson

Well, I ran a 8/2 wire 8' from the fully charged battery bank to the control module on the fridge and I'm still getting the blinking light. To me it seems that the fridge is running, turns off, then tries to turn back on too soon. All in all, it's off for under 2 minutes before it tries to cycle back on. Is this too soon? Temperature in the boat is 75 degrees right now, but this does it when it drops into the lower 50s during the night too.

mine cycles about 10- 15 mins off and about 5 mins on with ambient temp about 12 degrees celcius

senormechanico · 18-12-2012, 11:41

Imho, it would still be a good idea to check the voltage AT the fridge module to eliminate a low voltage problem, although it could also be moisture in the system freezing up and creating a blockage.
When it melts, it runs, freezes, creates the problem, melts, etc??
Paging Richard?

Richard Kollmann · 18-12-2012, 15:10

Three LED Flashes repeated every four seconds is indication of compressor overload and is normally caused by someone tampering with refrigerant. In this case no one has touched unit in last 4 years.

Because micro processor in module is unlike automobile computers it has only one memory and it is possible a one flash or two flash LED signal can be masked by compressor starting to recycle so quickly that refrigerant pressures cause high enough amperage to signal a three flash LED keeping compressor from starting. I am able to duplicate this false signal on my test stand. To eliminate possibility of a false signal overpowering first signal turn power off to refrigerator and watch for first LED signal when power is turned back on. If first signal is three flashes module needs to be tested. If first LED flash is only one flash and four second before the three flash starts again, trouble is in boat’s wiring, and not a refrigeration problem.

Matt Johnson · 18-12-2012, 16:17

Awesome information on the LED procedure! After following the advice, it seems that I get the three flashes right away and will need to have the module tested. When would you like me to send it your way? We are only a few hours away in St Augustine so the post office should be pretty quick getting it to you. If the holidays are busy, I could send it after the new year.

Thanks for all the help.

Matt