Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the
RCD after a few minutes - some time after the motor starts up. Once
it has tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle,
it will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor
against earth and got no hint of a short.

Any ideas?

On Fri, 03 Aug 2012 01:36:52 -0700, Ben Blaukopf wrote:

Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the RCD
after a few minutes - some time after the motor starts up. Once it has
tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle, it
will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor against
earth and got no hint of a short.

I'd suspect the heater...corroded or whatever. Might fit those symptoms.

Can you try other operations (e.g. cold wash, rinse) where the heater
will not kick in?

--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

On 03/08/2012 09:36 Ben Blaukopf wrote:

Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the
RCD after a few minutes - some time after the motor starts up. Once
it has tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle,
it will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor
against earth and got no hint of a short.

Any ideas?

Try the forum at
http://www.ukwhitegoods.co.uk/forums...forum.php?f=45

Really helpful.

--
F

In article ,
Bob Eager writes:
On Fri, 03 Aug 2012 01:36:52 -0700, Ben Blaukopf wrote:

Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the RCD
after a few minutes - some time after the motor starts up. Once it has
tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle, it
will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor against
earth and got no hint of a short.

I'd suspect the heater...corroded or whatever. Might fit those symptoms.

Can you try other operations (e.g. cold wash, rinse) where the heater
will not kick in?

A corroded washing machine heater can also trip and RCD when it's
not running, through a neutral/earth leak, although it's more certain
to do so when it switches on. Trying to run the machine on the same
program, but with both heater terminals disconnected (and well
insulated and tied out of the way) would be a reasonable confirmation.
(The program probably won't run fully as the water won't get up
to temperature, but it will avoid tripping the RCD if the heater is
the cause.)

Sometimes the heater casing gets damaged as the drum bearing wears
and the inner drum drops, causing it to start rubbing on the heater.
As I mentioned in another posting recently, check for this by seeing
if there's much relative movement between the inner and outer drums
by trying to lift the inner drum at the front.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 03/08/2012 09:36, Ben Blaukopf wrote:
Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the
RCD after a few minutes - some time after the motor starts up. Once
it has tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle,
it will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor
against earth and got no hint of a short.

Any ideas?

As the others mentioned, heater would be my first suspect. May not be
applicable to your model exactly, but this Bosch heater replacement
procedure might be of some relevance:

http://wiki.diyfaq.org.uk/index.php?...achine_repairs


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 3 Aug 2012 01:36:52 -0700 (PDT), Ben Blaukopf
wrote:

Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the
RCD after a few minutes - some time after the motor starts up. Once
it has tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle,
it will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor
against earth and got no hint of a short.

Any ideas?

You are unlikely to be dealing with a short to earth, much more likely
to be slight leakage, hundreds of k ohms.
It does sound as if it's the motor from what you say. check for carbon
deposits in the commutator and the brush carriers.

--
Graham.
%Profound_observation%

Graham. wrote:
On Fri, 3 Aug 2012 01:36:52 -0700 (PDT), Ben Blaukopf
wrote:

Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the
RCD after a few minutes - some time after the motor starts up. Once
it has tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle,
it will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor
against earth and got no hint of a short.

Any ideas?

You are unlikely to be dealing with a short to earth, much more likely
to be slight leakage, hundreds of k ohms.
It does sound as if it's the motor from what you say. check for carbon
deposits in the commutator and the brush carriers.

I had a machine that did this. striped it down to the drum motor and
stripped that. One of te commutator sigments showed 2k to the armature
metal - recon motor and it sorted it.


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

Brian Gaff wrote

How worn is the comutator though, often the debris here can give
unacceptably low resistances in some motors. Don't know spcifically about
this one though. I know those old vaccuum motors Hoover used were prone to
this.

That shouldn’t trip the RCD tho. That much more likely to be the water
heater etc.

"Ben Blaukopf" wrote in message
...
Washing machine (Bosch Exxcel WFX2868, 7 years old) is tripping the
RCD after a few minutes - some time after the motor starts up. Once
it has tripped once, it will trip again immediately if you turn it on,
but the short eventually clears. If you switch it to the drain cycle,
it will turn on and drain just fine.

There's about 2cm left on the brushes, and they seem to be contacting
fine (measured 2.4 ohms between brushes, no idea what the nominally
correct value is though). I measured all terminals on the motor
against earth and got no hint of a short.

Any ideas?