Danfoss Electronic Module - Help Needed

[ericoh88]

I have been using the danfoss 12v air cooled unit from Technautics for several months. Unit was installed by PO in 2002 in Fort Lauderdale.

The unit will run 24/7 consuming 3.5 amps (measured with clamp on meter).

Yesterday, I changed the thermostat setting a bit and the compressor stop working. When I by pass the thermostat terminals at the freezer section, I can see the fan at the compressor side turning. Supply at module is 13.30V with thick cables.

So I guess it may be compressor fault or the black box module which is an old unit without any led indicator.

I called Technautics and they say it is probably the electronic module because the fan will run whenever the compressor runs.

I understand that this module will modulate the boat's 12v into AC 3 phase so a direct 12V test on the compressor will ruin it.

Anyone had tried to replace some parts in the electronic module. I have the tools to do simple desoldering and replacing ic on pcb. Will probably open up the black box today as this requires removing 4 bolts for the whole compressor assembly as the black box is mounted close to a bulkhead which left little room for black box access.

Like to avoid another boat bucks .

Appreciate any suggestion or help.

[Richard Kollmann]

See If there are any wires connected to F terminal on module, If so disconnect them then see if compressor will run with a jumper wire across thermostat module terminals C and T. Use meter again to see amperage. The fan terminals Small + and F are limited to 1/5 amp. A bad fan bearing can cause current above 500 milliamps stopping compressor.

If you connect 12 volts direct to compressor field coils the compressor is then junk as one or more of the three field coils will be damaged.
A 13.3 volts reading is not a guarantee that a micro second voltage spike is not happening at compressor startup.

Three and Four pin Danfoss BD troubleshooting

If your refrigeration unit is over 10 years old and has a Danfoss BD 2 or BD2.5 or BD3 compressor then it has the older discontinued electronic 4 pin module.
Troubleshooting Danfoss compressors with 4 pin modules will consists of the following steps:

1. All of these compressors have a 4 pin module connector and their modules contain an external fuse. If this fuse is blown there are two reasons why either power wires to module are reversed or module has an internal failure.

2. Check to see that there is actually power at the refrigerator control module.

3. Place jumper wire across thermostat terminals on electronic module, Compressor still does not run go next step.

4. Disconnect black fan wire from electronic module, Compressor runs, replace fan. Compressor still does not run after fan ground wire is disconnected, go to next step.

5. Run correct size and correct polarity jumper wires direct from a fully charged battery in order to bypass all boat’s wiring. Volt meter readings are of no value when looking for voltage spikes. Compressor still does not run electronic module needs to be removed and tested on another unit. If there are no other units available to test your module on I will test all 12 volt Danfoss control modules free except for BD80 compressor modules. Small 12/24 volt boat refrigeration using Danfoss compressors manufactured after 1996 will have a BD 35 or BD 50 variable speed compressor with a troubleshooting computer chip built into their control module. This circuit makes them easier to find troubled area if compressor fails to run. If your unit does not have this $2 LED install one, as it could save you a lot of money later. Without the LED on these new units troubleshooting will be the same as earlier 4 pin Danfoss BD compressors.

Unfortunately trouble shooting LEDs are not installed on most units. I offer a kit that can be easily installed on the module.
There are installation instruction information at Danfoss and my web site as well as in my 12/24 volt refrigeration manual on Troubleshooting LEDs. If you would like the kit and step by step instructions with pictures, send $8 plus $4 shipping to me and I will mail you a complete kit. This simple device can save you refrigeration down time and hopefully large repair costs. If you understand LED applications and do not need the kit I still provide free refrigeration help on my forum or by email. I can also help with free 3 and 4 pin Control module testing..




If installed trouble shooting LED will only flash if electronic module sees a compressor problem. In each case problems of compressor’s failures to run are identified by Counting number of flashes of LED:

• No LED flashes would indicate either thermostat is open or no power to module.
• One LED flash and a 4 second pause indicates a boat wiring electrical resistance problem or low batteries. Because of modules sensitive to milliseconds of a voltage spick they cannot be detected by a voltmeter. Solution is to bypass boat’s wiring till problem is located. To isolate trouble follow instructions above in item number 5.

· Two LED flashes indicates fan over current cutout. If fan circuit on these variable speed compressors exceeds ½ amp compressor start up will be aborted. This condition can be confirmed by disconnecting Black fan wire at module if fan runs replace fan.

• Three LED flashes indicate excessive torque is required to start compressor. This is commonly caused by turning compressor off and back on too quickly or too much refrigerant or poor condenser cooling. Most people jump to the conclusion that there is a mechanical rotor lock up inside compressor and this is a mistake on Danfoss BD compressors.
• Four LED flashes indicate compressor motor not reaching sustained controlling speed above 1,850 rpm quick enough.

I closed my shop but after seeing what is being charged by boat refrigeration companies who will test modules charging $50 and charging as high as $385 for new 4 pin modules, I decided to test and sell modules for a fraction of what is currently being charged.

If your shipping address is in the US I will test your module on my Danfoss compressor refrigeration test stand. This test stand will run at max compressor load for a one hour. I will then return your module to you for a shipping and handling charge of $20.


Four pin modules for BD2.5 and BD3 twelve volt compressors only:
Three pin modules for BD35 and BD50 non Danfoss are also $150 plus $15 shipping

New module non Danfoss $150 plus $15 insured shipping. Modules will only be shipped to addresses in the US.

Because your unit is old and if it needs a new electronic module there is a risk that something is wrong that caused module to fail so most companies will refuse warranty of these modules. This is my electronic module warranty:

If any used module I sell fails to operate your unit it can be returned within 30 days for a full refund.
Any new non Dandoss module I sell 3 or 4 pin can be returned for full credit within 30 days. Because of my own risk involved for the next 11 months I will return only 50% of the new units purchase price if module is returned within the first year.

To have module tested or purchase a new three or four pin module send check to:

Richard Kollmann
2430 Sugarloaf LN
Ft. Lauderdale FL, 33312

Richard Kollmann
http://www.kollmann-marine.com

[ericoh88]

Hi Richard

Thank you for the speedy reply. Before I could open the module, another yachtie offered his old working module which he replaced with a new one thinking the old unit is initially faulty.

I swapped the module and the compressor jumped to life pulling the freezer down again. Now doing -7C and still going down !

I have attached 3 pics which showed 3 pin compressor connectors.

I am only guessing what cause the earlier module to blow out. I must have turned the thermostat to see where the click comes in and that perhaps cause a voltage spike to the module.

Richard, is this a common cause to destroy a electronic module?

Just PM you for the led kit and a new module as spare.

Thanks again for the great tip.

[Richard Kollmann]

Originally Posted by ericoh88

Hi Richard

Thank you for the speedy reply. Before I could open the module, another yachtie offered his old working module which he replaced with a new one thinking the old unit is initially faulty.

I swapped the module and the compressor jumped to life pulling the freezer down again. Now doing -7C and still going down !

I have attached 3 pics which showed 3 pin compressor connectors.

I am only guessing what cause the earlier module to blow out. I must have turned the thermostat to see where the click comes in and that perhaps cause a voltage spike to the module.

Richard, is this a common cause to destroy a electronic module?

Just PM you for the led kit and a new module as spare.

Thanks again for the great tip.

The 101N0210 module is a very smart microprocessor and any mistake you make with the thermostat knob should not cause damage. What can cause a module failure is turning off battery power and then turning it on again with engine alternator running.

Your pictures would seem to show water exposure on module and possible dirty wire terminal contacts. The amperage is low on all module contacts so they must be clean for module to work. The thermostat module contacts on C and T are carrying only from 5 to 1 milliamp depending on compressor speed yhis is about the same as a small flashlight so you can see the importance of good clean contacts.


Short Module Serviceable Life can be caused by how refrigerator was installed.

Danfoss has always experienced problems with electronic control modules on BD compressors. After ten to fifteen different Danfoss module models still randomly failures occur with no warning. If we exclude lightening strikes and corrosion due to water module failures seem to be caused by voltage spikes or heat.

Voltage spikes at module are not always visible with a meter and can be present on any boat. Unstable voltage is why the module must receive power direct from battery buss using correct size wiring, fuses, circuit breaker and switches that allow no voltage drop. When compressor is correctly wired to battery buss battery will absorb voltage surges like a very large electrical capacitor reducing module electronics failures. When refrigerator is powered from a branch circuit breaker panel any item in that panel can cause a damaging voltage spike when that item is powered up or powered down. Any relay when power is turned off sends a voltage spike back towards the source. Windless, power wench, generator start relays and even cabin light relays can damage refrigerator control modules if refrigerator is wired through a circuit breaker panel instead of main buss.

Module overheating maybe the primary reason for so many electronic control module failures. Through the years Danfoss has designed static air heat sinks on modules to conduct and radiate heat away from transistors and other components inside module. Module heat increases as compressor load (amperage) increases. Danfoss’s installation application data sheets have always assumed system designers and installers would insure compressor design power amperage limits were not exceeded. What you will find in the marine industry is the elimination of module and compressor cooling air along with higher than design compressor heat loads. Only Danfoss’s AEO modules have built in module cooling fans. Danfoss’s variable speed specifications for BD50 require an additional fan for cooling control module if compressor is to be operated at maximum capacity (3500 rpm). All of the following conditions can cause module overheat failures; High condenser cooling temperatures, Repeated attempts to start do to an overloaded compressor, First box temperature pull down in a hot climate, System ambient temperatures above 105 degrees F, and too large or poorly designed holding plate evaporator coils. Failure to maintain good cool flow of condenser air, a normal maintenance item, should not be overlooked as cause of module failure.

[SV THIRD DAY]

Great to hear it was just the Electronic Module like we discussed on the phone. Based on 45 years of experience in trouble shooting refrigeration systems over the phone (and now more frequently email), we are typically pretty good as asking the right questions to get the issue identified as quickly as possible. When someone’s refrigeration systems goes down it’s a “Cruise Crisis”, which is why we are available by phone 7 days a week for trouble shooting, so never hesitate to contact us at 619-609-3432.


It sure would be nice if there was a quick "put your leads here and read the voltage test” to determine if the Electronic Module was alive or dead, but without a direct test it's a matter of going through a few tests and Richard did a great job of walking you through them. Like in this case, we are usually able to nail things down over the phone by reviewing the data. For folks with a Technautics CoolBlue system, we also offer two options to nail down Electronic Controller issue by physically testing or swapping out the unit. We will also give a FREE error light LED upgrade to anyone with an older CoolBlue unit without one, just shoot me an email with the shipping address and off it will go via US Mail. (Info@TechnauticsInc.com)


Frist, we will test a suspected Electronic Module for FREE if they will ship it to us. We keep 2 CoolBlue units running in our test box for data gathering and testing, so it’s very easy for us to quickly put your suspect controller on a working unit to get an “alive or dead” determination. If dead, we can ship out a replacement. The negative here is the time delay in shipping but the positive is that an independent system of known status pretty much nails down the “dead or alive” question.


The second approach is a little more risky but can be faster. Faster because we can ship out a replacement Electronic Module more quickly, more risky because it is relying on there NOT being a fault with your system that will kill a new controller when we ship one out! While I don’t recommend this more risky approach to trouble shooting, some cruisers due to speed want to go this route. We can either send out an older “Test Controller” or a brand new unit based on how you want to go understanding that if the working controller “smokes” when attached to your compressor you now will now own two dead controller rather than one…Uggg. Being a cruiser live aboard myself I understand that sometimes the riskier approach is wanted because living aboard without a working refrigerator will make the Admiral unhappy real fast! Usually from the client information and after a few easy tests, we can get pretty close to the problem and minimize the risk or playing musical Electronic Controllers.


Besides the sale water environment, lighting, crappy voltage and voltage spikes, Heat is a killer of the Electronic Module. Most systems out there don't have any air movement on the Electronic Module to help dissipate the heat. Oe of the reasons we are able to offer the only 5 year warranty in the business is due to the CoolBlue design that has the fan blowing on the Electronic Module, which we have found helps keep it cooler and cuts down on the thermal death of the module...thus warranty claims.

[Richard Kollmann]

Rich, Now that you represent Cool Blue manufacturer what do you recommend for troubles with the round compressor's GD30FDC modules, used on the Cool Blue? I have an open trouble email on this module today. Randy at one time believed this module might be interchangeable with Danfoss BD50 3 pin modules? Who stocks these replacement modules and their costs? I have been suggesting in the past the complete system be replaced when there are problems. Grunert also used this compressor for a short time but now say they have no knowledge of it. I understand Technautic no longer uses these compressors?

[SV THIRD DAY]

Originally Posted by Richard Kollmann

Rich, Now that you represent Cool Blue manufacturer what do you recommend for troubles with the round compressor's GD30FDC modules, used on the Cool Blue? I have an open trouble email on this module today. Randy at one time believed this module might be interchangeable with Danfoss BD50 3 pin modules? Who stocks these replacement modules and their costs? I have been suggesting in the past the complete system be replaced when there are problems. Grunert also used this compressor for a short time but now say they have no knowledge of it. I understand Technautic no longer uses these compressors?

Please excuse my spelling and txt for this response since I am making this post from a Wendy's parking lot on my way to the Seattle Boat show. thumb tapping isnt my strong suit.

Fortunately the Cubigel compressor electronic module is very simular to the Danfoss (for all I know they used it as a starting point to copy). The 5 error code LED light flashes are the same so that helps in trouble shooting. An improvement we like is that the LED light is mounted on a small circut board along with manual speed control switches on top of the electronic module and plugs into the module via a phone jack/type connector. It makes for easy viewing and adjusting and can be mounted remotely from the electronic module as well.

while the electronic module is damn near identical to the danfoss, i can not say for sure that the two are interchangable at this point. it is a matrix box on the testing we have in progress, so i will be able to answer that question as soon as we put a unit through the paces.

we stock the controller for the older CoolBlue units made with the danfoss compressor and the newer CoolBlue units using the cubigel compressors here in California. we sell both electronic modules for the same cost.

Technautics made the switch from danfoss compressors to Cubigel when danfoss moved their production from Germany to China due to a large number of failures we experienced at the time. Im sure danfoss/china have now worked through those issues but we have found the reliability of the spanish made Cubigel units to be supperior to danfoss, which is why we feel pretty confident giving a full 5 year non prorated replacement warranty on our unit compared to the 1 year warranty the rest of the industry offers on their danfoss based systems.

we use the cubigel as the standard compressor in our coolblue systems, and are working to update the website photos that still show the older danfoss units in the photo (something that causes confusion) Randy just wasnt that good at websites and interacting in the internet world, something im more comfortable with.

If you have specific questions, we really are available 7 days a week for support on the phone or via email and skype.

[Lodesman]

Originally Posted by Richard Kollmann

5. Run correct size and correct polarity jumper wires direct from a fully charged battery in order to bypass all boat’s wiring.

Thanks for the great step by step, now here's my question:
I got to this stage and the unit runs; can you help me figure out where the problem might be?

If it helps, the boat's wiring measured 13.6v when disconnected from the module, but when I connected it to the module it measured 2.7v. Also on boat's wiring the LED stays lit continuously.

Also, is there any reason I shouldn't leave it connected directly to the battery, so I can have a fridge, until I get this sorted?
TIA

[Richard Kollmann]

Originally Posted by Lodesman

Thanks for the great step by step, now here's my question:
I got to this stage and the unit runs; can you help me figure out where the problem might be?

If it helps, the boat's wiring measured 13.6v when disconnected from the module, but when I connected it to the module it measured 2.7v. Also on boat's wiring the LED stays lit continuously.

Also, is there any reason I shouldn't leave it connected directly to the battery, so I can have a fridge, until I get this sorted?
TIA

Lodesman, You are lucky most times when this off brand compressor is used owners give up and switch back to a Danfoss BD compressor. Your testing of my trouble check #5 confirms the no start problem is a low voltage spike during compressor start up caused by resistance in boats wiring and not a refrigeration unit trouble.

The question is it the ground wiring connections, or somewhere in positive side of boat's refrigerator supply wiring. I would check all of the refrigerator ground wire connections first. If unit is still operating on the jumped battery, Disconnect ground jumper and re connect original ground system. If compressor runs then you know trouble is the grounding wire system.

If grounding wire checks out then start at circuit breaker for refrigerator as these inexpensive unit’s contacts can create high resistance over time especially if used as a switch. Your 11 volt voltage drop from battery to control module is conformation of a major resistance somewhere in positive or negative wiring. Each wire terminal and connection is to be bypassed until compressor will start and run on 12.4 volts. Forget the 0.3 or 0.5 voltage drop others may quote.

[Lodesman]

Thanks Richard, that clarifies it nicely. Just came back from Xmas dinner with the other boaters, so I'll tackle it tomorrow. Thanks again.

[Jim Cate]

For the two Richards:

If all the marine service providers were as kind, generous and conscientious as you two, the yottie world would be a far better place. Well done to both of you!!!

I hope to never have fridge problems, but I know where I will look for help if I should be so unfortunate. Thanks for being there.

Jim

[CS Cruiser]

What Jim Cate said, happy new year all!

[SV THIRD DAY]

If I had a dollar for every suspected Electronic Module failure that turned out to be an electrical wiring issue, maybe I could take a real vacation and not give the 7 day a week 365 day a year phone and email service....but them again what would I do anyway....retire? I already tried that and its too boring.

The problem is that no one wants to believe that its the wiring and not the module. It like you are blaming their boat (child) for the problem and I've had people almost beg me to buy a new controller because the thought of that is easier then troubleshooting their boat electrical system. As an owner of a 1978 boat with vintage electrical I get it...trust me.

If you need any help even on new years day, just email or call me and I'll be happy to help.
Phone 619-609-3432
Email Info@TechnauticsInc.com

[Blue Stocking]

Originally Posted by CS Cruiser

What Jim Cate said, happy new year all!

X 3 Thanks guys.

[katsumi]

Hi Richard
I have a Isotherm fridge with a Danfoss compressor and Electronic module 101N0210.
I have been reading through a lot of your posts trying to troubleshoot a fault I have.
Wondered if you could help.
My fridge does not have problem cooling, the fault I have is the compressor will run for a while then switch on and off approx10 to 20 seconds over a period of approx 2 minutes then run for a minute and then same thing on and off.
I have fitted an LED to the Pos and the D terminal no indication comes up at all.
I have tried disconnecting the fan and still the fault occurs.
As I mentioned the fridge keeps cool, I just think the constant starting and stopping is consuming my batteries.
I would appreciate any help you can give me to find this fault.
Regards
Nick