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Our Bosch washing machine has suddenly started tripping the house RCD. The machine is about five-ish years old, is used nearly every day and has never given us any electrical problems before.
It happens as soon as I turn the main control knob to one of the programmes – it can sit in the ‘off’ position without any problems. It could be that it trips as soon as the programme actually starts, but I’m not sure, and need to check that.
So, are there any known problems with this model at this age? Perhaps an internal water leak? I’m just asking before I take the covers off for a peek inside, in case it is a common fault.
— Jason
Re: Bosch WDL2000 tripping house RCD
The two most common components that cause the RCD to trip when faulty are the motor and the heater element. To check these you can disconnect them (one component at a time) and see it it still trips. With the heater, make sure you take off both wires, in the case of the motor there is a multi pin plug.
Re: Bosch WDL2000 tripping house RCD
Thanks for the quick response. I’ll check both these today.
Just a quick question: the machine trips the power within seconds of starting the programme. The motor is on, but the water is still filling up. I assume the heating element would not be turned on until the machine is full, so is it more likely to be the motor then?
— Jason
Re: Bosch WDL2000 tripping house RCD
The heater could still cause the RCD to trip even when not turned on. It would only need it’s neutral terminal to be connected as the RCD can detect earth leakage to neutral. Sometimes you get a hole in the heater and it shorts to earth as soon as the water reaches the level of the hole.
Re: Bosch WDL2000 tripping house RCD
Phidom wrote:…It would only need it’s neutral terminal to be connected as the RCD can detect earth leakage to neutral…
Okay, so it’s just switched on the live. Makes sense.
— Jason
Re: Bosch WDL2000 tripping house RCD
Phidom wrote:The two most common components that cause the RCD to trip when faulty are the motor and the heater element…
It no longer trips when the motor is disconnected. What would be the next step? Removing the motor and giving it a good clean? Could this kind of fault just be caused by a build-up of carbon dust?
There are a few spots of rust on the underside of the motor, but that looks like it has been splashed up from the underside rather than water dripped through from the top. Otherwise, apart from the wires and connector being covered in carbon dust, it looks clean and tidy.
So – to clean the motor or replace it? Is this always going to be a replace/part exchange job, caused by insulation breakdown?
— Jason
Re: Bosch WFL2000 tripping house RCD
Remove the motor and check the brushes. Also look carefully at the insulation in which the copper strips of the commutator are embedded. Sometimes this insulation material cracks and the crack fills with carbon dust. In such cases the only solution is a replacement motor. Also look at the wiring harness to the motor. There may be a chafed wire touching something metal.
Re: Bosch WFL2000 tripping house RCD
Hi,
I took the motor out and cleaned out the dust and carbon from around all the electrical bits:
I suspect the brushes are a little worn down:
This has led to some scoring down the middle of the armature contacts:
All pictures:
http://www.flickr.com/photos/8461387@N0 … 860358073/
However, after all that cleaning and checking of the cables etc. it still trips the RCD the moment the motor tries to turn. Unless there is something else I can look at, I suspect this will be a write-off. With new motors seemingly running at £150, it probably looks like a whole new washer would be better value (Bosch WAE28364GB £400? Whirlpool AWO/D 6927 £307).
Unless anyone has any ideas or knows where I can get a cheaper replacement motor from?
— Jason
Re: Bosch WFL2000 tripping house RCD
Those brushes are worn out so you need to try it with new ones before you can tell if the motor has failed. You can scrape carbon dust out of the gaps between the copper strips using a sewing needle or thin jewelers screwdriver.
if that motor even runs, or lasts more than a wekk, ill platt fog!
id be looking to replace the motor
helo_75 wrote:if that motor even runs, or lasts more than a wekk, ill platt fog!
It doesn’t run, so you are okay.
I have dismantled the motor completely and there is a dead short between the coils and the shaft. One of the coils looks like it has overheated as the insulation on it has gone black and crispy.
Now, just a theory – but if the brushes got low enough, could that have caused the motor to stick and burn out just one coil to the point where its insulation failed? Or does this kind of thing ‘just happen’ to motors anyway?
— Jason
PS I think I just accidentally clicked ‘ignore’ against your username, what with the button being right next to ‘reply’. I’m not sure how to undo that.
Re: Bosch WFL2000 tripping house RCD
The carbon came out pretty easy with a small paint brush and compressed air. Having removed the armature, I’ve found it has a short-circuit from the coils to the chassis, so I think it is a goner.
In this picture, the two copper-coloured spots in the dead centre of the picture are bare copper – the insulation just fell off.
http://www.flickr.com/photos/8461387@N0 … 8/sizes/m/
— Jason
Re: Bosch WFL2000 tripping house RCD
New Bosch motors are expensive but if there is a shop in your area that sells reconditioned washing machines they might be able to sell you a secondhand motor.
Re: Bosch WFL2000 tripping house RCD
I tried phoning around and could not find anywhere that kept old machines or parts any more. There was once a time when a place near Newcastle would always have a spare part they could pull from a machine in their warehouse, but alas our modern *consume/dispose* culture does not allow for reuse any more.
To cut a long story short: I put it up on freecycle, where it was snapped up in minutes. Seems there are a lot of people out there with duff drums and good motors.
I’ve ordered a new machine, which should arrive tomorrow. These credit-crunch times seem to be the *best* time for buying white goods since the market is so competitive (until *too many* suppliers go out of business, that is).
Thanks for your help all, yet again. I’ll leave the photos up indefinitely in case they are of help to others.
— Jason
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