Checking advice for a Bosch Washing Machine tripping RCD

[shukerr]

Hi,

I have a Bosch washing machine that is 4.5 years old and has started tripping the RCD as soon as the motor starts.

With the earth spade disconnected from the motor then the RCD doesn't trip and the motor works.

I spoke to a local repairer and he advised that motors can develop some earth leakage over time and also that our old RCD could be over sensitive. I've checked and cleaned the brushes and commutator etc and they are fine.

He advised that leaving the earth spade disconnected with some electrical tape to insulate is an acceptable permanent solution so long as the resistance between live and earth on the motor is not less than 0.5 Mega Ohms.

I checked and the lowest resistance I could get was 0.7 mega ohms and that went to infinite with the brushes removed.

I just wanted to get a second opinion on here if this is an acceptable permanent solution.
After all, the rest of the washing machine is fully earthed and if there is a short circuit in the motor then it will simply blow the fuse right.

Opinions please?

 

[jj4091]

Buy a new motor

 

[raykf]

You might try: remove the motor give it a good wash out with brake cleaner followed by a good blast with an airline.
It may just be carbon deposits from the brushes providing a path from live parts to chassis.....

 

[flameport]

He advised that leaving the earth spade disconnected with some electrical tape to insulate is an acceptable permanent solution

He is wrong.
There is a fault, which is why the RCD trips.
The permanent solution is to repair the motor, or replace it.

Disconnecting earth wires is never acceptable.

so long as the resistance between live and earth on the motor is not less than 0.5 Mega Ohms.

0.5M for a motor or anything else is grossly lower than it should be.
It should be many 10s of Mohms at least. Preferably 100s.

 

[danechip]

I would replace your local repairer first of all. Disconnect the Earth lug? What a tnuc!! Surprised he didn't suggest changing your RCD for a nail.

Name and shame, we could send him a polite email.

 

[75pete]

I would look at the interference capacitor. This little £20 item was my problem. On my machine it was very easy to remove and replace. I started by checking the connections of the power cable for any damage then after that the next thing was this capacitor. Can't easily check it but and mine had no signs of heat damage etc. Found a replacement and fitted, only had to take the top off the machine and remove a couple of screws. So, if your machine trips the house RCD as soon as you switch on the machine (not the circuit mcb) it could be this.