Miele Fridge Freezer Please Help

[jmsa7]

Hello,

My Miele Fridge Freezer stopped cooling following a storm causing an electrical surge that also damaged other appliances. Everything else works fine like lights, fans, touchscreen control unit but seems like compressor is not running.

I found some swollen capacitors in the control unit which were replaced but didn’t fix the problem.

There is an Embraco VES Inverter unit next to the compressor and 2 cables connected to it. I can confirm 240V going to Inverter and the other cable has 3 wires which come from the control unit and are labelled TX, RX and Gnd. I believe the compressor is being controlled with some kind of serial communication, maybe RS232.

Is there a way of checking that the inverter is receiving the right signals?

I would also like to check and maybe replace the inverter unit as I believe it might be faulty but can’t figure out how to take out and the compressor pipework is blocking it. Please see photo attached.

https://ibb.co/r0xNP4M

The appliance model is Miele KFN 29243 D ed/cs

Any suggestions much appreciated. Thank you.

Regards

J

[northy303]

Do you have the wiring diagram for the unit and I will tell you what to check. I don’t think you have an inverter they are usually on bigger fridges and aircon systems

[Tony R]

There are 3 different inverters listed for that model, I will need the index number from the rating plate to identify which inverter you have on yours, there can also be a set of green lights that flash in the inverter which are fault code indicators.

[northy303]

just checked that compressor and the inverter board gets its signal from the control board somewhere else in your fridge this has the thermistor plugged in to it probably where you turn the temp up and down. I would check to see if the thermistor is ok first and has not shorted out with the power surge.
then check the control board to see if it is receiving voltage and sending the signal to turn on the compressor. It is plugged in to cn05 on the inverter board which is your tx and rx and is the white and brown cable plug (brown being the live) then if all that is working then you need to unplug the compressor, turn the unit back on and see if you have a balanced output from the inverter board pin to pin on the plug (3 readings) ac voltage should all read the same.Then last of all check if your compressor is not down to earth and measures the same resistance pin to pin. obviously I Hope you can use a multimeter.
Good luck.

[Tony R]

If you have as you state mains to the inverter, then checking compressor windings will not indicate a good compressor, even if you have continuity between all 3 pins. There are three possibilities for the compressor not running, 1 no frequency signal from the control PCB, 2 inverter error and 3 compressor failure.
If you have tried to repair the PCB, that would probably be the first thing to replace with a new genuine part.

[northy303]

If thermistor is short or open line- New thermistor required
If no power at control board – New inverter board required
If no power at signal connector on inverter board but power at control board- New control board required
if power at signal connecter on inverter board but no balanced ac output on 3 leads going to compressor when unplugged from compressor-New inverter board required.
if all these readings are ok then you have a seized compressor- New compressor required

[jmsa7]

Tony R wrote:If you have as you state mains to the inverter, then checking compressor windings will not indicate a good compressor, even if you have continuity between all 3 pins. There are three possibilities for the compressor not running, 1 no frequency signal from the control PCB, 2 inverter error and 3 compressor failure.
If you have tried to repair the PCB, that would probably be the first thing to replace with a new genuine part.

Hi Tony. Thank for your email. After doing further testing I came to the conclusion that the problem is with the Inverter. Please see photo:

http://ibb.to/s1N1W2M

Do you know where I can get one or equivalent?

[jmsa7]

northy303 wrote:If thermistor is short or open line- New thermistor required
If no power at control board – New inverter board required
If no power at signal connector on inverter board but power at control board- New control board required
if power at signal connecter on inverter board but no balanced ac output on 3 leads going to compressor when unplugged from compressor-New inverter board required.
if all these readings are ok then you have a seized compressor- New compressor required

Thank you for your reply northy. I now proved the problem to be with inverter:

http://ibb.to/s1N1W2M

Do you know where I can get one?

[Tony R]

Like I have said before, there are 3 different inverters used on that model, so the index number found after the model number on your badge is needed.
Regards, Tony.

[jmsa7]

Tony R wrote:Like I have said before, there are 3 different inverters used on that model, so the index number found after the model number on your badge is needed.
Regards, Tony.

Hi Tony, please see a photo of my inverter here:

https://pasteboard.co/J85gMhs.jpg

The other link is broken. Cheers.

[Tony R]

Ok, the part number is on the inverter,it is the 6145482-00 number, this is also a Liebherr recognized part number, they list part 6145482-00 as an inverter for the compressor VES 2456 97 F00, these type of parts are not generally supplied direct to customers other than service providers, however you may be able to buy it on this sites spares section.

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