Bosch Logixx 7 washing machine tripping house RCD

[zipper]

As a multimeter only puts out a couple of volts the best you can hope for is that any faulty component will measure a couple of kΩ when you meter it to earth. So put your multimeter on the highest resistance range (if it isn't auto ranging) then isolate each component in turn by taking out the it's connection plug & measure its resistance to earth. You might be lucky & get a reading if there is a flat earth someplace. Start with the motor, & work your way through the pump, valves, suppressor etc. If they all show infinity then its back to square one.

 

[dazzystar]

Hi,

When I disconnect the earth from the motor it seems to be fine. I put it on a spin cycle for a few seconds and all appeared well.

What should I check for now?

Cheers
Daz

 

[dazzystar]

Another update.

I removed the cable tie from the harness close to the motor and gave the earth wire a little more movement. Reconnected the earth to the motor and set it on a 400rpm spin. All was well for about 20 seconds and as the motor started to spin faster the RCD blew.

Any clues?

Cheers
Daz

 

[dazzystar]

Yet another update:

I cleaned out the pump filter which had a few bits of debris tried the 400rpm spin again but this time after pressing the start button and the door clicking the RCD tripped.

 

[zipper]

Have you tried your multimeter on the motor? Are there any signs of water leakage in the machine?
Check for cable damage to the motor, might also pay to remove the motor altogether & give it a good blow out with dry compressed air to get out all the carbon dust. Then check the brushes.

 

[dazzystar]

Hi Zipper,

No sign of a single drop of water anywhere. Very clean and tidy. Where would I connect my MM to and what test would I be performing? Would the brushes cause this problem as the motor runs without its earth connected.

Cheers
Daz

 

[zipper]

As a multimeter only puts out a couple of volts the best you can hope for is that any faulty component will measure a couple of kΩ when you meter it to earth. So put your multimeter on the highest resistance range (if it isn't auto ranging) then isolate each component in turn by taking out the it's connection plug & measure its resistance to earth. You might be lucky & get a reading if there is a flat earth someplace. Start with the motor, & work your way through the pump, valves, suppressor etc. If they all show infinity then its back to square one.

 

[nicam49]

Well, I wish dazzystar had finished this interesting thread! Usually it's the heater because either the drum bearings have worn so much that the inner drum flops about and starts to grind into the heater casing until it exposes the element, but, particularly on the Bosch, inexplicably the spider fractures(!) and THAT causes the inner drum to flop about with the same result. However, if it is the heater with an earth fault, then in my experience the heater doesn't get power applied till some 10 minutes after the machine is filled with water.... so in dazzystar's case the fault was very much looking like the drum motor? But, as the motor casing is insulated from earth by plastic bushes, and he'd disconnected the earth wire from it.....or does the PUMP run at the same time as the spin?.....could it have been that?.. 'cept originally he said rcd tripped immediately on switch on when NOTHING would be running, maybe a filter capacitor on the circuit board was leaky? Any Bosch washin' machine (no 'G') gurus out there with any ideas? cheers!

 

[sircerebus666]

You do know that this thread is over 7 years old?

Theres a good chance that dazzystar has sorted the problem by now......