WAECO CF40 fridge dead on 12V, good on 240

Kenm4 · Member

RE: WAECO CF40 fridge dead on 12V, good on 240

Kenm4 · Member

Unfortunately the 12 volt power does not hold long. I can run no worries on 240, then power off disconnect 240 power up 12 volt and it will run for 5 seconds before the 12 volt supply drops off. I have checked the wires I reconnected after the bridge test and think I have them right. Is it the case that the 240 supply holds in a relay for a few seconds after power is disconnected, thus allowing 12 volts to flow temporarily to the compressor.

DeBe · Guru

Is your controller a 101N0500 with the 240v supply built in? If it is there is no relay, it uses a solidstate switching device (MOSFET) to change over supplies.

Kenm4 · Member

Yes it is the 101no500 does that mean that I have stuffed it.

DeBe · Guru

It doesn't look good for the controller. The controller I have the 240V side is burnt out, so I just use it on 12V.

Kenm4 · Member

I saw somewhere that a new controller is approx. $300, and I would like to run it on 12 volts if I can. Question 1 If I disconnected 240v supply to the controller and bridged the C and T on the controller would the thermostat and other controls work normally. I have an old Ups that I can hook to my van batteries to run the waeco on 240 volts and suffer the conversion loss. Question 2 is would the UPS be pure sine wave, keeping in mind they were designed to keep PCs running on a power shut down

DeBe · Guru

If you bridge C & T you are bypassing the thermostat & it will run continuously. If you fit an external electronic thermostat that is where you connect it to. Now not all UPS are sinewave a lot are squarewave. Yes the controller is around $300.

Kenm4 · Member

Thank you until I determine the UPS will not hurt the waeco electronics I will run it through My onboard Pure sine wave inverter in the Van. May have to bite the bullet later and pick up a controller.

kev071 · Member

Hi All,

I have the same controller as Noremac01 has (101N0500) but mine isnt working on 240v, 12v is working good.

There is 240vac and 330vdc at the bridge rectifier but I dont know where it goes to from there.

i would of thought it should step down prior to going to the bridge rectifier, could it be the step down transformer, if so which one is it?

Before I pulled it apart when on 240v the panel and error light would flicker (not flash) but not compressor or fan starting.

any ideas?

DeBe · Guru

101N0500 Block diag.jpg 101N0500 Controler.3.JPG 101N0500 Controler.4.JPG It will be quite a challenge to repair the 240v part of the controller. You are dealing with a Switch Mode Power Supply. Posted the block diagram of the unit & pictures of the board that I have marking the 240V side. I found its easier & cheaper to just use the unit on 12V dc & use a 240v/12v dc powersupply if you want to use it on mains.

-- Edited by DeBe on Sunday 5th of August 2018 04:36:34 PM

Harrer94 · Member

Hi have the same issues. 12 volts on my cf 60 stopped working. Since a couple of days 230volt doesn't work either anymore. Only emergency mode. What do I need to do? Pls help me out. I'm on my travel next week again and need it fixed. Cheers Florian

DeBe · Guru

If it works on emergency then the compressor & its controler is ok. But will need a picture of the other board, to see which type it is & does the display light up?

Harrer94 · Member

So cleaned the board with degreaser, wd40 and a toothbrush. 240v working again, but still issue with 12volts

landy · Guru

Hats off to you Debe. That's a great job your doing there. My fridge is working fine but it is always good to see somebody that has the skills giving their time to help people in need, Well done mate.
Landy.

-- Edited by landy on Thursday 5th of March 2020 09:56:51 PM

Chrs_tof · Member

Hi guys, its my turn for my waeco cf50 to only work on 240v. I have the danfoss 101n0500 board. New fresh battery 12v cable connected directly to the danfoss board on the compressor... no power on display at all, no noise nothing. Tried bridging terminals C And T no such luck. Any other suggestions? Thank you kindly

DeBe · Guru

So it works on 240V but not on 12V? Does the display work on 240V?

dabbler · Guru

My Waeco CF has a habit of altering settings when it shuts down on DC. It then stops working on DC OR drops the temps to freezer level but okay on AC. Not every time but often enough to learn a solution. On AC, cycling through the settings and changing the preferred low voltage cutoff to something something else THEN cycle again this time changing to the preferred low voltage cutoff value. Sounds crazy I know but when you're off grid you and have a dodgy fridge you try all sorts of things.

Chrs_tof · Member

DeBe To answer your question only on 240v does the display come alive. 12v I get absolutely nothing not even and error code Thanks

DeBe · Guru

WAECO CF-40AC. PCB.2.jpg DANFOSS, 101N0500. CONTROLER.JPG Hope these are the same as your boards. The circuit board has a 3 terminal regulator. Check that there is 12V where marked & 5V. Do this test only on 12V as theres 240V AC on this board if pluged into the mains.

Chrs_tof · Member

DeBe thanks again for your reply. Yes the boards look the same. I seem to be getting 12.8v across right across that voltage regulator on the board. Also getting 12.8v at terminals A and C. Would this suggest the voltage regulator is cooked?

DeBe · Guru

12V at A & C is correct. But there should be 5V betwean GND & 5V, not 12V.

Chrs_tof · Member

I replaced the voltage regulator and still the same. Unless there is a short in the board somewhere. I was even getting 12v on the middle pin which is meant to be ground?

DeBe · Guru

Sounds like theres a missing ground to the board. There should be near 0 ohms from the reg ground to 12V Ground.

Chrs_tof · Member

Any suggestions to check where may be missing the ground?

DeBe · Guru

WAECO CF-40AC. PCB.2.jpg DANFOSS, 101N0500. CONTROLER.JPG Check for continouty betwean GND on the Reg to each of the points circled in yellow.

Chrs_tof · Member

So I'm not getting continuity on the 12v negative terminal on the danfoss board and the D port on the smaller board all other highlighted terminals had continuity. Could this mean there may be a fault in the danfoss board?

Chrs_tof · Member

I just noticed you didn't actually circle terminal D on the smaller board. So the only pin I'm not getting continuity on is the negative pin in the 12/24v on the danfoss board. Sorry for the confusion there.

DeBe · Guru

DANFOSS, 101N0500. CONTROLER.JPG 101N0500 Controler.3.JPG On this board there should be continuity from the REG GND to pin C 12V neg. The switching MOSFET that i have marked connects the 12/24V NEG pin to C, when the unit is powered by 12/24V.

-- Edited by DeBe on Tuesday 17th of November 2020 08:45:21 AM

Chrs_tof · Member

Sorry for the delay had a few things going on. Just checked for continuity and there is continuity between the ground on the mofset and pin c.

Phillipn · Guru

I had the same problem. The 12 v lead where it plugs into the fridge buggars up. $ 20 at Vidcam for a new 12v lead fixed the problem.

Test the lead with a multi meter and it will read OK, The plastic fitting spreads and losses contact.