Beko WMB71231W Trips RCD

[Brendarran]

I have one that is doing my nut in and I cant find the issue with it. I am probably not seeing the wood for the trees but I could do with some help please.

As mentioned the Beko WMB71231W keeps tripping the RCD. The washer belongs to a regular customer of mine and I have been out numerous times to clear debris and nitrile gloves from the machine (used in a workshop to clean overalls). I was called out the first time because it had finished the cycle and water was still in the machine (this is usual for them) but this time it had tripped the RCD. I checked the drain pump and it was gubbed. I fitted a new pump and the machine worked perfectly. Half an hour later I get a call that its tripped the RCD again. I go back and test the various washer components but can find any fault with any of them. I test the wiring and no obvious faults are found I end up systematically disconnecting the components and reconnect them one at a time to try to replicate the fault on my PAT test. The fault is eliminated away when I disconnect the motor. I test the motor and tacho again but no fault is found. The brushes are fine and there are no shorts to earth. I run the washer in test mode and the fault has gone but obviously the motor doesn’t run. I reconnect the motor and disconnect the motor feed plug from the PCB and this eliminates the fault also. I test the motor again and the wiring from the plug to the motor and all is as it should be. I try the motor again but no fault is found, again. I have a motor in the van so I connect that and the issue is gone. I plug in the machine and run it in test mode and then a full cycle and it works brilliantly.

You guessed it, half an hour later I’m called by the customer saying that it has tripped the RCD again!!! 😡

Only component that I haven’t looked at very closely is the PCB. I go over the PCB with a fine comb but can find no issues. I try out a new PCB thinking that a faulty motor may have blown the motor triac relay on the PCB. The fault still remains!!

I cannot find any leaks to earth and no obvious faults with the wiring. Sometimes I only have to turn the appliance on and it trips and the next I can get the program to run as far as rotating the drum before it trips.

Does anyone have a schematic of the wiring on these machines that I can study please? I’m sure I’m missing something that’s staring me in the face!

Any help would be much appreciated! :tup:

Thanks
D

[wilf]

Re: Beko WMB71231W Trips RCD

sounds like a harness fault. I’ve had a couple where the wires rubbed through to the cabinet near the interlock and vibrations caused a short. no RCD makes it easier as you can see the blow mark, but in this case you’l have to look very closely

wilf

[Brendarran]

Re: Beko WMB71231W Trips RCD

Thanks Wilf.

I have been suspecting a wiring fault but numerous tests and I cant find a short. I might resort to removing the loom and going over it with a keen eye.

Thankfully I have an old Hotpoint lying around that they can use until I find the fault. I prefer to do jobs like that in the comfort of my own workshop without the customers breathing down my neck and asking questions. As much as I like the guys (I used to work with them) workshop banter is not good for concentration. ha ha

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