Dometic CFX 65W 12V Electric Powered Portable Cooler (Fridge Freezer)... Trouble.

[OzePete]

Originally Posted by Richard Kollmann

OzePete, Pete, You, must agree the same unnecessary pointless foolish arguing does not alter the facts as you seem to infer.
Richard, to disagree with a statement that is blatantly wrong, is not “pointless foolish arguing” it is getting facts out there so readers are properly informed! You stated that these compressor motors are quote “small brush-less DC motors” when they are nothing like that, they are three phase AC motors.
In order to understand the operation of these small systems it is imperative to understand that the motor is 3 phase AC. To believe otherwise makes it impossible to understand or learn how the system works as the compressor motor is at the heart of the system and integral to all other electrical, electronic and mechanical components. Sorry Richard but the facts are simply the way it is. You can’t make a silk purse out of a sows ear (being polite!) and you can’t talk a small brush-less DC motors into being a 3 phase AC motor!

These Direct Current compressors do not have brushes whether armature excitation is with two field coils or three. Electrical pulse current direction within module eliminate the need for armature brushes. The electronic control module’s electronics are different but both versions of boot up voltage and amperage protection functions are much the same. Both the three and four pin Danfoss BD compressor modules convert 12 or 24 volt DC to pulsating low voltage AC current.

Without an oscilloscope to see the same low voltage spike that control module sees and terminates compressor start up you will not see with a voltmeter. I find that a person looking for Low voltage spikes is better off isolating away the cause and leave the voltmeter in the tool book.

Richard I don’t think you grasp the difference between a DC power supply and ‘Spikes’! The term ‘Spikes refers to transient voltages which nearly always originate from elsewhere and are extremely erratic. What you are incorrectly calling a ‘Low voltage spike’ is simply the collapse of voltage /current due to compressor start load and most likely coupled by a poor power supply. (Bad connection, cable, battery failure etc) The incidences of true low voltage spikes are as rare as hens teeth, but then add to that the possibility of such a ‘Low voltage spike occurring just as the compressor tries to start, all makes winning the lottery look easy!
Low voltage transient spikes are not the issue, a sudden drop of voltage due to defective supply is. All readable with a decent digital multimeter.

If you ask a owner technicians like at technautics or Cold Ed Marine they will confirm that a voltmeter will detect voltage drop but not a low voltage spike that is the number one cause of Danfoss BD compressor restart problems. Number two is a faulty fan.

Thank you Richard, for the suggestion of seeking advice from Cold Ed Marine, but having been in the Refrigeration industry for 57+ years, owned and operated many successful companies, engineered and built thousands of various sized systems, I doubt that I will be seeking advice from someone who apparently built their first refrigeration system 2 to 3 years ago!



Hopefully PetePetePete will advise the forum when problem is located and corrected is without modification or replacement.

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[PetePetePete]

So I spent the better part of tonight trying to sort this out... and honestly, I have nothing.

The battery was fully charged -- but now I'm questioning the battery I was using, which I think is grasping at straws because I know what I've done before with the same variables (except for this particular freezer).

Anyway... the battery was at 12.50vDC (whit for a Optima Blue-Top isn't that great) on the DMM, the App showed it at 12.35. Ok. I guess .15vDC isn't a huge deal.

Then I power the unit up. 11.81vDC on the DMM and 10.9vDC on the App... Which jives with the previous numbers when the freezer was in the boat. At this point I am 100% certain that the boat's wiring is not the issue.

Both house batteries are new in July 2018... and both check out. All my voltages on the boat check out with the Victron and match the DMM readings.

I have tried a longer set of alligator clip leads, and a shorter set. There is no significant difference (.1vDC, at most)... So I do not believe drop is an issue.

I have tried it with the cigar end on and with it off... no difference.

I think I'll try it with another battery, but at this point, there is definitely something that isn't right... but I want to exhaust every possible scenario.

I'll post more in a bit when I try yet another power source. After 3 sources, if I can't figure it out, I'm going to have to call Dometic and let them sort it out.

[PetePetePete]

Just set it up in my car. I used the cigar plug -- because frankly, that's not relevant.

The moment I turned the car off the voltage on the app dropped to 10.6... moments later I started getting a single amber flash which indicates there is inadequate voltage to run the unit.

I'd love to hear suggestions, but this isn't going to work.

[Richard Kollmann]

The next step is to power unit direct eliminating cigar plug and its cord. If this does not solve problem the trouble is most likely in the DC AC converter's electronic switch if your unit has an internal converter.

I have to apologize for the sale-mans side tracking remarks he does this when I attempt to help boaters..

[PetePetePete]

The cigar plug is of no consequence. I have bypassed it several times in several scenarios.

My final guess is that there is either an issue with the voltage reading circuitry... or there is something that is causing an out-of-spec power draw.

[Richard Kollmann]

I believe the first time you indicated the Yellow LED flashed a trouble code is when it was plugged into car. The single flash code does now indicate a voltage drop and not a microsecond low voltage spike. The condition in the car also confirms that trouble is not with boat's battery or boats wiring. Now if you are saying it is not the cigar power cord the trouble has to be inside the portable refrigerator electrical.

I do not know what size fuse is inside Cigar plug probably no larger than 15 amps or what size circuit breaker for refrigerator in boat and they did not trip with a load inside potable refrigerator that can continue to drop voltage while reducing battery capacity ia a new mystery. Any power to compressor should have stopped when LED started flashing. If you are dealing with this much current flow there should be heat or sparks somewhere. It is unfortunate that you can not reach the control module to see if it is very warm.

It your unit has two power cords AC and DC then they both may pass through a converter with a two position switch normally in the DC position unless there is AC power connected. Now that Danfoss has offered the 101N0500 multiple voltage modules it could be the source of problem. If this unit does have dual power cords how does it perform on AC power source? One thing for sure this problem has nothing to do with soft or hard starting loads. Another point if module sees very high starting amperage a three LED code every four seconds would occur.

[PetePetePete]

Originally Posted by Richard Kollmann

I believe the first time you indicated the Yellow LED flashed a trouble code is when it was plugged into car. The single flash code does now indicate a voltage drop and not a microsecond low voltage spike. The condition in the car also confirms that trouble is not with boat's battery or boats wiring. Now if you are saying it is not the cigar power cord the trouble has to be inside the portable refrigerator electrical.

I do not know what size fuse is inside Cigar plug probably no larger than 15 amps or what size circuit breaker for refrigerator in boat and they did not trip with a load inside potable refrigerator that can continue to drop voltage while reducing battery capacity ia a new mystery. Any power to compressor should have stopped when LED started flashing. If you are dealing with this much current flow there should be heat or sparks somewhere. It is unfortunate that you can not reach the control module to see if it is very warm.

It your unit has two power cords AC and DC then they both may pass through a converter with a two position switch normally in the DC position unless there is AC power connected. Now that Danfoss has offered the 101N0500 multiple voltage modules it could be the source of problem. If this unit does have dual power cords how does it perform on AC power source? One thing for sure this problem has nothing to do with soft or hard starting loads. Another point if module sees very high starting amperage a three LED code every four seconds would occur.

I'm working with tech support and going to do some tests testing voltage at the black electronic module. As well as directly behind the input end of the 12vDC terminal and noting any deltas, etc.

The unit functions 100% perfectly on AC power. This issue is entirely limited to 12vDC function only.

I will know more, yet again, tonight. I won't give up. LOL.

[PetePetePete]

Well! We have an update!!

... Drum roll please ... LOL.

The problem was the wire - not the cigar plug... the actual WIRE. Go figure.

I alligator clipped it right at the female power input port to a battery. The voltage shown on the app and the voltage with the multimeter was only about .2vDC off. When I use the wire (with the cigar plug and fuse removed) the difference is over 1vDC.

I should have gotten the hint -- when I spoke with tech support the first thing they said is that they would send me a new wire. Duh. I'm an idiot -- obviously they likely had an inkling. LOL.

I'll report back after I get the new wire.

[a64pilot]

Originally Posted by Richard Kollmann

If you have confirmed that at Low battery protection there is still a compressor restart up problem 40% of the time it is the wiring between refrigerator and battery. I get this same complaint emails 3 to 5 times a month. I recommend troubleshooting to bypass all the the boats wiring, Switches, Circuit breaker, and wire connections with fused jumper large wire cables direct from unit to Battery

Post number 16.

However I suggest reading the rest of the post that I cut out as there is good info there as well.
Like for instance why you may not see a low voltage event with a multimeter that prevents compressor start for instance.

However I suggest you do without the cigar plug, it will eventually give you trouble, they just aren’t good for higher amp, voltage sensitive loads

[Uncle Bob]

Originally Posted by PetePetePete

Well! We have an update!!

... Drum roll please ... LOL.

The problem was the wire - not the cigar plug... the actual WIRE. Go figure.

I alligator clipped it right at the female power input port to a battery. The voltage shown on the app and the voltage with the multimeter was only about .2vDC off. When I use the wire (with the cigar plug and fuse removed) the difference is over 1vDC.

I should have gotten the hint -- when I spoke with tech support the first thing they said is that they would send me a new wire. Duh. I'm an idiot -- obviously they likely had an inkling. LOL.

I'll report back after I get the new wire.

Great news, for a disconnect if you don't wish to permanently hardwire it may I suggest the range of Anderson plugs. I find them excellent.

[OzePete]

Originally Posted by Uncle Bob

Great news, for a disconnect if you don't wish to permanently hardwire it may I suggest the range of Anderson plugs. I find them excellent.

Good advice Bob, a decent lead with Anderson plugs.

This problem is typical of the vast majority of compressor start failures, as many here have constantly suggested in this and other threads.... A POOR POWER SUPPLY! This can be because of several causes like faulty/ inadequate cable, bad connection, faulty battery etc.

The fridge compressor module reacts to the voltage available at it's input terminals, as it attempts to start and will shut down if the voltage drops excessively.

This entire saga could have been put to bed earlier by simply using a good digital multi-meter to read the voltage at the *DC power in terminals on the Motor Driver Module (Black box) Not at the battery, only at the module, voltage at the battery tells you nothing! (* if spade connectors are used, check voltage from the male terminals as the female spade may be the issue)

Read the voltage prior to and when the compressor tries to start. A vast difference in these two reference voltages would confirm a poor power supply.. simple!

Cheers OzePete

[Richard Kollmann]

PetePetePete you are not the first one to find that voltmeter reading looking for a compressor boot up problem wasted a Great deal of time. Rich now owner of Technautics has posted Unless you have SUPERMAN"S EYES you will not see a low voltage short duration spike with a voltmeter. Another reason for item 3 on my Danfoss compressor no start troubleshooting chart is to leave voltmeter in tool box. Those service engineer with experience has run into this problem more than once. Three years ago there were two compressors replaced because of undetected low voltage and later the new replacement compressors had the same problem.

[SV Xpensive Care]

Had problems initially with my CF-50. From that I found Dometic Tech-Service to not have the remotest clue of how refrigerators (any refrigerators!) work. I replaced the OEM power cord end with a BlueSea plug, and had already installed a BlueSea receptacle connected to my 12V source with tinned 10Ga wire. After several months of arguing simple logic with Dometic, they replaced my original unit with a new one which has been running as advertised for a year.
Dometic had suggested I cut off the 12V plug & hot-wire it direct to the battery, too but that takes away any fuse protection it had. The only way I would know there was a problem then would be as it burst into flames.
I have bought a lot of Dometic equipment over the years and unhesitatingly bought this one at a boat show. I'm still a fan of the brand, but their Tech Service department sux.

[PetePetePete]

Originally Posted by Bob Gates

Had problems initially with my CF-50. From that I found Dometic Tech-Service to not have the remotest clue of how refrigerators (any refrigerators!) work. I replaced the OEM power cord end with a BlueSea plug, and had already installed a BlueSea receptacle connected to my 12V source with tinned 10Ga wire. After several months of arguing simple logic with Dometic, they replaced my original unit with a new one which has been running as advertised for a year.
Dometic had suggested I cut off the 12V plug & hot-wire it direct to the battery, too but that takes away any fuse protection it had. The only way I would know there was a problem then would be as it burst into flames.
I have bought a lot of Dometic equipment over the years and unhesitatingly bought this one at a boat show. I'm still a fan of the brand, but their Tech Service department sux.

The guy in the service department I've been talking to is Jack -- he's pretty good.

The end-issue isn't even the cigar end of the plug. LOL. I took that apart and wired it from the two prongs to hot 12VDC and it still had the problem. It was only when I alligator clipped it right at the unit (bypass the entire factory supplied wire) that it worked like it should.

The problem is either with the plug that goes into the cooler (on the wire side) or the with the part before it migrates to the cigar.

I am always suspect when the first thing do is blame the boat wiring or something because I'm so anal about the way I do things.

LOL. I keep a written log of when I BoeShield my electrical connections, etc. I go over my adhesive heat-shrink connectors with additional heat shrink... the stuff I do makes people think I'm crazy.

When a person goes right to the old "Is the computer plugged in" or "power on power off" crap it drives me mad.

If I didn't do the basics, I wouldn't be talking to you. LOL.

Hopefully the new plug solves the problem.

[George DuBose]

I have had Dometic sales people that didn't even know their units were multivoltage.

I asked Dometic for the RAL number for the color of the top of the CF120 so I could match the new countertop in my galley. Their colors are "trade secret". Ha!

If you hard wire your Dometic to a battery or other constant power source, just install an in-line fuse for your protection. Using a cigarette lighter socket is a no-no, too much current loss from the weak connection and corrosion.