I have a CF 50 AC VER B. S/No 10026206 which switches off as soon as connected to 12V, and on 240, has no temp control. Panel says -6, but inside temp is -20.
I'm guessing I had a dud thermistor, and probably a dud board.
Can anyone point me in the right direction as I'd like to have a go at fixing this myself. I'm reasonably handy and can use a multimeter, which I always have on hand.
I believe they are all much of a muchness. As such there is quite a deal of information on them. The thermostat would be my bet . What to do is take off the bottom cover. you will find a microprocessor panel attached to that, remove that. It has several plugs plugged into it, the one you want has a black lead, from memory , bottom right hand corner. Unplug that. Now test on ohms for 10K at 25 degrees I got about 16K at 9 degrees. If you want to see it work, heat the bottom centre of the inside of the freezer box to see the resistance drop. your one may have a spare hanging aboit so if you find a spare unplugged lead check it out it may just be an easy swap. If not, my idea with this you can find under fixing a CF40. I bought 2 thermostats on EBay for $4 they are waterproof so Im not going to cut plastic and rip our insulation . If it only works on AC, the most likely thing is it has a relay on the power panel, DC and relays never did it for me, a clonk with a screwdriver could free it but don't expect that to last. You could test that by touching with a PP9 battery, that should have enough to make it tick. + to the cathode of D8, - to the anode. Rob
Thanks for that DeBe, you know your subject. It was you who saved me hours trying to figure the thing out. Oh and as a matter of interest on my CF40 with the transition diode short, is this common or did some idiot plug the 24V line into the mains? thanks Rob.
DeBe the boards you show are the same as mine. As is the Danfoss 101N0500.
I disconnected the thermistor connection and at 15 degrees the resistance was 7.05, disconnected from the board, across the board pins resistance was 14.64, reconnecting the wire resistance changed to m13.59.
I've tried to attach images of all the boards in my unit which will hopefully work.
Are you sure you are reading your meter correctly. By this I mean you don't sound like someone who would spend hundreds of dollars on a top of the range meter. With that in mind, I think what you are reading is not ohms but K ohms. If so it looks like you are not so lucky the thermistor looks as if it may be OK. To test that. If you have a hair drier, warm the centre of the lower inside of the freezer compartment to see if the resistance drops. No hair drier, use a bucket of warm water. If it is OK, Im out, wait and see if De Be has something. Rob
You don't need an expensive meter at all. A $9 dig multimeter from Jaycar will do the job fine. That's what I purchased in Cairns to work on my daughters 12V refrigeration on her Yacht. Tailor your meter should be fine.
That reading is quite ok. Since you have said the compressor doesn't run on 12V DC, we need to establish that the Electronic unit on the compressor is OK. So put the module back together & re fit to compressor @ wire it up. Leave the 240V disconnected & just power it with 12V. Remove the thin wires on the terminals C & T. Bridge C & T with a shorting link. With in one minute the compressor should start & will continue to run with the shorting link in place. This test is to prove that theres no fault with the Module. Also make sure there is actualy 12V DC on the Positve & Negative terminals on the module.
Just to clarify a point. When I talked about an expensive meter it was because you gave a reading of 7.35. If this was ohms not many ordinary meters would do that. So no I was not getting snobby about meters. At the moment I run an Aldi special and its just as good as the fluke I had for many years. Rob
I've replace all the boards, and connected the unit to 12V. The output from the transformer was exactly 12V. Testing the positive and negatives also showed 11.98V on the module. I've bridged T & C as shown.
After 10 minutes nothing has happened, except the interior light blinks.
I'll have to give that some thought since I have a couple of EvaKool fridge freezers, which have better warranties, and in my experience actually honour them.
I have a Evakool 47 litter fiberglass & its better insulated than the Waeco 40 that I have. Best of luck with what ever you decide, but the control modules are quite expensive for the Danfoss compressors.
Waeco don't seem interested in selling to individuals, and can't see any other source. Will sit on the damned thing or a while.
Yes, the Evakool fiberglass models are extremely well insulated. We have a number in the family and they have never let us down. I did buy an IB70 from their seconds shop and that even came with a 5 year warranty. I did have a problem with it, and after they tested it had no hesitation in replacing it.
An update on this Waeco.
Seeing they are so sensitive to voltage, I decided to hook up directly to a battery with 12.8V. This had no desired effect, and I was still only getting 11.89V at the module.
Yesterday in desperation I bought a 45 litre from Aldi, 2 year warranty, since if they aren't Waeco they come from a similar factory. The 12V cord looks very much like the Waeco, but fits a little tighter. Plugged it in and all of a sudden the compressor is running on 12V.
A closer look seems to indicate that the pins in the Waeco are not making proper contact, thus creating some resistance.
I've just put it on, on 12V and the temp has dropped 3 degrees in about 10 mins. It has also run on 240, but I want to see if the 12V will work OK, then see if the 240 will hold a set temp.
Set for 0 degrees, on 12V got down to -6 before I switched to 240. Have set it to -10 degrees, now the display is showing -4 but the interior is -18.
Would guess its the thermistor, but could it be something else???
I am surprised that the low voltage fault did no cause the red fault LED to flash the code of one flash repeated. An easy way to fit a replacement thermistor, is per these pictures, The temperature readings are very close on settings around 1-2 deg. On freezing temps they are quite a bit off, but at lest the fridge does cycle.
When I had the original fault, the red light did flash and the compressor turned off. Since we have been working on it, that hasn't been the case.
The option you have used to replace the thermistor is really easy, a good idea.
My Evakool IB100 also had a dodgy two pin plug. Evakool offered to replace it with a different fitting, but I needed the freezer for the next few months so wired in an Anderson plug. No worries about that getting loose and 6mm wire lead, no voltage drop.
