My condenser tumble dryer keeps tripping the main 80A switch on my CU.

It runs fine (on half heat setting) for about 40 mins, then trips.

The socket in use is in the garage approx 5 mtrs direct spur to the CU in
the garage on a 16A circuit breaker which does not trip.

Nothing in the house except the fridge/freezer on the kitchen circuit is on
(apart from Sky box on standby) no electric shower etc.

Any ideas?

TIA
--
Vass

Vass wrote :
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

Might that be an RCD type 80A?


It runs fine (on half heat setting) for about 40 mins, then trips.

Sounds like an RCD trip rather than a trip on over current.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Sun, 15 Nov 2009 12:07:09 -0000, Vass wrote:

My condenser tumble dryer keeps tripping the main 80A switch on my CU.

"Switch"? I think you mean RCD as normally the "main switch" in an CU
has now fault or overload function it is just a switch.

Assuming that it really is an RCD the the chances are that the dryer
has an earth leakage fault, this is fairly commmon. Probably have to
repalce the heating elements.

--
Cheers
Dave.

Vass wrote:
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

It runs fine (on half heat setting) for about 40 mins, then trips.

The socket in use is in the garage approx 5 mtrs direct spur to the CU
in the garage on a 16A circuit breaker which does not trip.

Nothing in the house except the fridge/freezer on the kitchen circuit is
on (apart from Sky box on standby) no electric shower etc.

Any ideas?

TIA


earth leakage issues.

Possibly damp electrics in the unit, or neutral/earth short on the ring.
Or a slightly high impedance joint that puts a spike on the mains when
it switches on or off, and allows transient earth currents through all
the capacitors in the RFI filters around the house.




Fit a 100mA 60A trip if you have a 30mA, and fit RCBO's to the 13A
sockets on the ground floor rings, and check for earth neutral shorts.
If it still happens, fix the bloody drier! I had a washing machine like
this. windings on a motor were shorted to the amarmature.

"Harry Bloomfield" wrote in message
. uk...
Vass wrote :
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

Might that be an RCD type 80A?

sorry yes, wrong term apols


It runs fine (on half heat setting) for about 40 mins, then trips.

Sounds like an RCD trip rather than a trip on over current.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Dave Liquorice" wrote in message
ll.co.uk...
On Sun, 15 Nov 2009 12:07:09 -0000, Vass wrote:

My condenser tumble dryer keeps tripping the main 80A switch on my CU.

"Switch"? I think you mean RCD as normally the "main switch" in an CU
has now fault or overload function it is just a switch.

yes RCD (sorry)

Assuming that it really is an RCD the the chances are that the dryer
has an earth leakage fault, this is fairly commmon. Probably have to
repalce the heating elements.


replace dryer is easier I think :-(

"The Natural Philosopher" wrote in message
...
Vass wrote:
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

It runs fine (on half heat setting) for about 40 mins, then trips.

The socket in use is in the garage approx 5 mtrs direct spur to the CU in
the garage on a 16A circuit breaker which does not trip.

Nothing in the house except the fridge/freezer on the kitchen circuit is
on (apart from Sky box on standby) no electric shower etc.

Any ideas?

TIA


earth leakage issues.

Possibly damp electrics in the unit, or neutral/earth short on the ring.
Or a slightly high impedance joint that puts a spike on the mains when it
switches on or off, and allows transient earth currents through all the
capacitors in the RFI filters around the house.




Fit a 100mA 60A trip if you have a 30mA, and fit RCBO's to the 13A sockets
on the ground floor rings, and check for earth neutral shorts. If it still
happens, fix the bloody drier! I had a washing machine like this. windings
on a motor were shorted to the amarmature.


sounds like its the dryer, I will just throw it out. and get a new one

thanks for advice,

Vass presented the following explanation :

"Harry Bloomfield" wrote in message
. uk...
Vass wrote :
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

Might that be an RCD type 80A?

sorry yes, wrong term apols


That could be be either damp causing leakage or probably even more
likely the heating element on the point of failing/burning out. You
could check the element for leakage to earth with a megger, but a rough
check which might work is to disconnect just the element and then try
running it - providing the machine itself doesn't then go into a fault
condition and promptly shut itself down.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Harry Bloomfield" wrote in message
. uk...
Vass presented the following explanation :

"Harry Bloomfield" wrote in message
. uk...
Vass wrote :
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

Might that be an RCD type 80A?

sorry yes, wrong term apols


That could be be either damp causing leakage or probably even more likely
the heating element on the point of failing/burning out. You could check
the element for leakage to earth with a megger, but a rough check which
might work is to disconnect just the element and then try running it -
providing the machine itself doesn't then go into a fault condition and
promptly shut itself down.

hmm found these elements
http://www.amazon.co.uk/dp/B002CHL2G...linkCode= asn
before I jump in and buy a new unit, I will give your idea a go. £ 50 is a
better option :-) thanks
--
Vass

"Harry Bloomfield" wrote in message
. uk...



That could be be either damp causing leakage or probably even more likely
the heating element on the point of failing/burning out. You could check
the element for leakage to earth with a megger, but a rough check which
might work is to disconnect just the element and then try running it -
providing the machine itself doesn't then go into a fault condition and
promptly shut itself down.

right, its running now without heater element connected,
will report back in an hour
--
Vass

On Sun, 15 Nov 2009 12:48:18 -0000, "Vass"
wrote:


replace dryer is easier I think :-(

Replacing heater elements is usually fairly straightforward. The
other thing to check is if it has a noise filter like

http://www.tdspares.co.uk/proddetail.asp?prod=cap2004

These can fail to giver the symptoms you describe.

"Dave Liquorice" wrote in message
ll.co.uk...
On Sun, 15 Nov 2009 12:07:09 -0000, Vass wrote:

My condenser tumble dryer keeps tripping the main 80A switch on my CU.

"Switch"? I think you mean RCD as normally the "main switch" in an CU
has now fault or overload function it is just a switch.

Assuming that it really is an RCD the the chances are that the dryer
has an earth leakage fault, this is fairly commmon. Probably have to
repalce the heating elements.


It's been a while since I've had to delve inside a tumble drier, but the
ones I've come across have an open type heater, where the resistance wire is
sprung between mica or ceramic supports.

How can a heater fail, apart from carbonised fluff bridging to an earthing
point? Where perhaps a good blast of compressed air would solve the
problem?

"Fredxx" wrote in message
...

"Dave Liquorice" wrote in message
ll.co.uk...
On Sun, 15 Nov 2009 12:07:09 -0000, Vass wrote:

My condenser tumble dryer keeps tripping the main 80A switch on my CU.

"Switch"? I think you mean RCD as normally the "main switch" in an CU
has now fault or overload function it is just a switch.

Assuming that it really is an RCD the the chances are that the dryer
has an earth leakage fault, this is fairly commmon. Probably have to
repalce the heating elements.


It's been a while since I've had to delve inside a tumble drier, but the
ones I've come across have an open type heater, where the resistance wire
is sprung between mica or ceramic supports.

How can a heater fail, apart from carbonised fluff bridging to an earthing
point? Where perhaps a good blast of compressed air would solve the
problem?


well, disconnecting it has stopped it tripping after an hour of use.
i will pull the heater out and take a look.
thanks
--
Vass

"Vass" wrote in message
...


"Fredxx" wrote in message
...

"Dave Liquorice" wrote in message
ll.co.uk...
On Sun, 15 Nov 2009 12:07:09 -0000, Vass wrote:

My condenser tumble dryer keeps tripping the main 80A switch on my CU.

"Switch"? I think you mean RCD as normally the "main switch" in an CU
has now fault or overload function it is just a switch.

Assuming that it really is an RCD the the chances are that the dryer
has an earth leakage fault, this is fairly commmon. Probably have to
repalce the heating elements.


It's been a while since I've had to delve inside a tumble drier, but the
ones I've come across have an open type heater, where the resistance wire
is sprung between mica or ceramic supports.

How can a heater fail, apart from carbonised fluff bridging to an
earthing point? Where perhaps a good blast of compressed air would solve
the problem?


well, disconnecting it has stopped it tripping after an hour of use.
i will pull the heater out and take a look.
thanks


heater looks fine, clean and undamaged. However there is evidence of wet
fabric particles all around the fan area
small clumps of it but not near the elements.
--
Vass

Vass wrote:

My condenser tumble dryer keeps tripping the main 80A switch on my CU.

It runs fine (on half heat setting) for about 40 mins, then trips.



earth leakage issues.

Possibly damp electrics in the unit, or neutral/earth short on the
ring. Or a slightly high impedance joint that puts a spike on the
mains when it switches on or off, and allows transient earth currents
through all the capacitors in the RFI filters around the house.


Fit a 100mA 60A trip if you have a 30mA, and fit RCBO's to the 13A
sockets on the ground floor rings, and check for earth neutral shorts.
If it still happens, fix the bloody drier! I had a washing machine
like this. windings on a motor were shorted to the amarmature.



sounds like its the dryer, I will just throw it out. and get a new one

Before going down that route, it might be worth noting that it sounds as
if you have a "whole house" RCD which can be a PITA even with correctly
working appliances if enough of them gang up on you. Dave's solution
would be a good one to implement anyway to stop you losing all power on
a trip.


--
Cheers,

John.

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

On Sun, 15 Nov 2009 14:52:35 -0000, Fredxx wrote:

It's been a while since I've had to delve inside a tumble drier, but the
ones I've come across have an open type heater, where the resistance
wire is sprung between mica or ceramic supports.

Sounds a bit of fire risk with the amount of fluff that is about in a
tumble drier. The one I took apart and cleaned(*) had a couple of
coiled mineral insulated elements bit like those on an electic cooker
but shaped like the coiled CFL lamps. Mineral insulated heaters are
prone to leakage.

(*) The single shot over heat stat operated it was that going that
prompted me to investigate. Both elements and the ducting where
heavily caked in fluff and a couple of places said layer of fluff on
the elements was decidedly charred...

This was a condensing dryer so the air is heated and circulated
rather than a vented drier with heats the (relatively clean) incoming
air then dumps it.

--
Cheers
Dave.

Ummm...

1 - Many driers now do use open-coil elements
This I do not like re fluff & fire hazard - I too prefer mineral
insulated.

2 - One RCD may be sensititised by other appliances
An RCD typically trips at 23mA - not 30mA. If enough appliances leak
1-2mA then they can get up to about 10-12mA earth leakage, only needs
12mA on the tumble dryer or anything for nuisance tripping.

3 - If you have sockets without RCD, buy a plug-in RCD & test
Stick the dryer on a plug-in RCD into non-RCD sockets. If you need to
use an extension lead it MUST be 1.25mm and FULLY unwound because a
dryer will turn it into a molten glued-together mess (or fire).

4 - If the CU is a split-load, add RCBOs on non-RCD side
For example lights down, kitchen sockets, outside socket, etc.

5 - If the CU is 1-RCD re whole-house or TT, again RCBOs
Basically provide individual RCBO protection where possible.
Particularly for kitchen or utility room - so they don't trip the
rest.

It could be the AC fan with damp fluff, or the motor - thus far it
sounds like the heater. Change the heater and see how things go - if
you can strip the machine and get the fluff out of it.

The fluff is in fact lint and it is highly flammable, worth having a
smoke alarm above any dryer because if the belt snaps there is a time
before the overheat sensors kick in. I am not convinced the overheat
thermostat will kick in before any lint around the heater has gone up
in smoke.

Fredxx wrote on 15/11/2009 :
It's been a while since I've had to delve inside a tumble drier, but the ones
I've come across have an open type heater, where the resistance wire is
sprung between mica or ceramic supports.

Ours use an element similar to an immersion heater element, except of
course, not submerged in water. The element runs inside a copper tube
mineral insulated, I think. The element can start to break down and
become conductive to the earthed copper sheath.


How can a heater fail, apart from carbonised fluff bridging to an earthing
point? Where perhaps a good blast of compressed air would solve the problem?

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On 15 Nov, 12:41, The Natural Philosopher
wrote:
Vass wrote:
My condenser tumble dryer keeps tripping the main 80A switch on my CU.

It runs fine (on half heat setting) for about 40 mins, then trips.

The socket in use is in the garage approx 5 mtrs direct spur to the CU
in the garage on a 16A circuit breaker which does not trip.

Nothing in the house except the fridge/freezer on the kitchen circuit is
on (apart from Sky box on standby) no electric shower etc.

Any ideas?

TIA

earth leakage issues.

Possibly damp electrics in the unit, or neutral/earth short on the ring.
* Or a slightly high impedance joint that puts a spike on the mains when
it switches on or off, and allows transient earth currents through all
the capacitors in the RFI filters around the house.

Fit a 100mA 60A trip if you have a 30mA, and fit RCBO's to the 13A
sockets on the ground floor rings, and check for earth neutral shorts.
If it still happens, fix the bloody drier! I had a washing machine like
this. windings on a motor were shorted to the amarmature.

To ensure discrimination the 100mA main RCD should be type S time
delayed otherwise there is high likelihood that it will trip at the
same time as the RCBO and you end up with the lights and other
circuits out all over the house. If your RCD is your main switch do
not reduce it from 80A to 60A. There are options for protecting the
downstream circuits such as all circuits on RCBOs or splitting the
board. into protected sub-groups. If you want to go down that route
get hold of a copy of the on site guide to BS7671-2008

"js.b1" wrote in message
...
Ummm...

1 - Many driers now do use open-coil elements
This I do not like re fluff & fire hazard - I too prefer mineral
insulated.

yep, there is a row of 4 open coil elements, but they all look pretty clean


3 - If you have sockets without RCD, buy a plug-in RCD & test
Stick the dryer on a plug-in RCD into non-RCD sockets. If you need to
use an extension lead it MUST be 1.25mm and FULLY unwound because a
dryer will turn it into a molten glued-together mess (or fire).

I could move the garage sockets to the other side of the split CU

4 - If the CU is a split-load, add RCBOs on non-RCD side
For example lights down, kitchen sockets, outside socket, etc.

the non RCD side has 2 x 16 unused and a 32 (in use for shower)


It could be the AC fan with damp fluff, or the motor - thus far it
sounds like the heater. Change the heater and see how things go - if
you can strip the machine and get the fluff out of it.


Leaving it plugged in to the same socked with no changes at the CU
disconnecting the heater and running it for an hour did'nt trip.
So, can I be confident its the heater elements? or, could this just reduce
the load
when in fact it could be the combination of the motor etc ??
--
Vass

Vass wrote:


Leaving it plugged in to the same socked with no changes at the CU
disconnecting the heater and running it for an hour did'nt trip.
So, can I be confident its the heater elements? or, could this just
reduce the load
when in fact it could be the combination of the motor etc ??

sadly yes.

Disconnect the lot, and put a resistance meter between heating coils and
earth., There should be NO detectable resistance there. If there is its
definitely new coil time. If there isn't, sadly it doesn't rule them
out, because they might short only when hot.

I hate intermittent faults. The Freelander had occasionally failed to
start for 18 months, until one day no amount of waiting, thumping the
bodywork near the fuel pump etc etc made it do so. Finally, I thought,
we can trace this fault..and know we have found it. New fuel pump and
off she goes.

After serious thinking The Natural Philosopher wrote :

Leaving it plugged in to the same socked with no changes at the CU
disconnecting the heater and running it for an hour did'nt trip.
So, can I be confident its the heater elements? or, could this just reduce
the load
when in fact it could be the combination of the motor etc ??

sadly yes.

Leakage can add up, yes.


Disconnect the lot, and put a resistance meter between heating coils and
earth., There should be NO detectable resistance there. If there is its
definitely new coil time. If there isn't, sadly it doesn't rule them out,
because they might short only when hot.

Or it might be more susceptible under pressure of mains voltage - which
is where a megger comes in.

What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be possible
to clean them. Not suggesting it would work, but might carburreter
(sp?) cleaner not be effective in cleaning this off?

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Harry Bloomfield wrote:
After serious thinking The Natural Philosopher wrote :

Leaving it plugged in to the same socked with no changes at the CU
disconnecting the heater and running it for an hour did'nt trip.
So, can I be confident its the heater elements? or, could this just
reduce the load
when in fact it could be the combination of the motor etc ??

sadly yes.

Leakage can add up, yes.


Disconnect the lot, and put a resistance meter between heating coils
and earth., There should be NO detectable resistance there. If there
is its definitely new coil time. If there isn't, sadly it doesn't rule
them out, because they might short only when hot.

Or it might be more susceptible under pressure of mains voltage - which
is where a megger comes in.

What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be possible to
clean them. Not suggesting it would work, but might carburreter (sp?)
cleaner not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on cookers
etc show now visible sings of anything, but did show leakage to earth.

"The Natural Philosopher" wrote in message
...
What about the insulation supporting the heater coils, any signs of burnt
on carbonised fluff? If they are pot (??) it should be possible to clean
them. Not suggesting it would work, but might carburreter (sp?) cleaner
not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on cookers
etc show now visible sings of anything, but did show leakage to earth.

Bought a new dryer. the doubt was not worth testing.
Anyone want a condenser dryer that might only need a £ 40 fix?

"Vass" wrote in message
. uk...


"The Natural Philosopher" wrote in message
...
What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be possible to
clean them. Not suggesting it would work, but might carburreter (sp?)
cleaner not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on cookers
etc show now visible sings of anything, but did show leakage to earth.

Bought a new dryer. the doubt was not worth testing.
Anyone want a condenser dryer that might only need a £ 40 fix?

I thought this was a DIY group? :-)

I believe the resistance of carbon goes down with temperature so in your
case it's even more likely to be a wisp of carbonised fluff and nothing else
wrong with the element !!

Fredxx wrote:
wrote in message
. uk...


"The Natural wrote in message
...
What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be possible to
clean them. Not suggesting it would work, but might carburreter (sp?)
cleaner not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on cookers
etc show now visible sings of anything, but did show leakage to earth.

Bought a new dryer. the doubt was not worth testing.
Anyone want a condenser dryer that might only need a £ 40 fix?

I thought this was a DIY group? :-)

I believe the resistance of carbon goes down with temperature so in your
case it's even more likely to be a wisp of carbonised fluff and nothing else
wrong with the element !!


I just cannot understand any form of logic that suggests buying a
replacement and scrapping the old one compared to spending £40 on a
repair especially when the machine has been opened up already.

Sheer madness!

Bob

"Bob Minchin" wrote in message
...
Fredxx wrote:
wrote in message
. uk...


"The Natural wrote in message
...
What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be possible
to
clean them. Not suggesting it would work, but might carburreter (sp?)
cleaner not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on cookers
etc show now visible sings of anything, but did show leakage to earth.

Bought a new dryer. the doubt was not worth testing.
Anyone want a condenser dryer that might only need a £ 40 fix?

I thought this was a DIY group? :-)

I believe the resistance of carbon goes down with temperature so in your
case it's even more likely to be a wisp of carbonised fluff and nothing
else
wrong with the element !!


I just cannot understand any form of logic that suggests buying a
replacement and scrapping the old one compared to spending £40 on a repair
especially when the machine has been opened up already.

Sheer madness!

Bob


cos if its not the heater then I'm £ 40 + new dryer down

"Vass" wrote in message
...


"Bob Minchin" wrote in message
...
Fredxx wrote:
wrote in message
. uk...


"The Natural wrote in message
...
What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be possible
to
clean them. Not suggesting it would work, but might carburreter (sp?)
cleaner not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on
cookers
etc show now visible sings of anything, but did show leakage to earth.

Bought a new dryer. the doubt was not worth testing.
Anyone want a condenser dryer that might only need a £ 40 fix?

I thought this was a DIY group? :-)

I believe the resistance of carbon goes down with temperature so in your
case it's even more likely to be a wisp of carbonised fluff and nothing
else
wrong with the element !!


I just cannot understand any form of logic that suggests buying a
replacement and scrapping the old one compared to spending £40 on a
repair especially when the machine has been opened up already.

Sheer madness!

Bob
cos if its not the heater then I'm £ 40 + new dryer down

But you're now a new dryer down, and you've already determined the cause to
be the heater. How much was the new dryer?

Some people have money to burn!

"Fredxx" wrote in message
...

"Vass" wrote in message
...


"Bob Minchin" wrote in message
...
Fredxx wrote:
wrote in message
. uk...


"The Natural wrote in message
...
What about the insulation supporting the heater coils, any signs of
burnt on carbonised fluff? If they are pot (??) it should be
possible to
clean them. Not suggesting it would work, but might carburreter
(sp?)
cleaner not be effective in cleaning this off?

Dunno what the coils are like, but all the failures I've had on
cookers
etc show now visible sings of anything, but did show leakage to
earth.

Bought a new dryer. the doubt was not worth testing.
Anyone want a condenser dryer that might only need a £ 40 fix?

I thought this was a DIY group? :-)

I believe the resistance of carbon goes down with temperature so in
your
case it's even more likely to be a wisp of carbonised fluff and nothing
else
wrong with the element !!


I just cannot understand any form of logic that suggests buying a
replacement and scrapping the old one compared to spending £40 on a
repair especially when the machine has been opened up already.

Sheer madness!

Bob
cos if its not the heater then I'm £ 40 + new dryer down

But you're now a new dryer down, and you've already determined the cause
to be the heater. How much was the new dryer?

Some people have money to burn!


Another way of looking at it is that after replacing the elements - it may
not be long before another significant repair is needed. Such items are
built with a finite life in mind (unfortunately). With some items
replacement becomes an inevitability. I regret ever repairing and upgrading
my first PC. After spending quite a lot it eventually became clear that I
had reached the point where I was flogging a dead horse.

"Owain" wrote in message
...


Use the motor for a somersaulting scarecrow?


exactly ! :-)
--
Vass