[Mano]

OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having
to reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new
devices etc and its happened day and night so its not something we are
manually turning on or off.

any ideas where to start ?

[Tuthledeen]

"Mano" wrote in message
...
OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having to
reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new devices
etc and its happened day and night so its not something we are manually
turning on or off.

any ideas where to start ?

Switch off individual breakers and see when/ if the problem goes away. After
determining the circuit at fault you can then isolate individual appliances
on that circuit until you isolate one that causes the problem to go away.
You then attend to that appliance. If you can identify an individual circuit
that has problems but no appliance has a problem, then you have wiring/
wiring fitting problems.

If the problem doesn't go away at all using any of the checks above you
then, most probably, have a defective MCB.

I think you may have some confusion between the function of an mcb and that
of an rcd. The mcb will trip if the circuit current exceeds the value quoted
on the mcb, whereas the rcd will trip if the difference in the current
flowing in the live and neutral conductors exceeds a minimal value, normally
30 mA (30 thousandths of an ampere). The two devices are intended to protect
you against rather different circuit faults and may well be protecting you
against fire at this very moment.

Call in a qualified electrician and get it sorted! Don't do any nasty
desperate bodges!

[Tuthledeen]

"Tuthledeen" wrote in message
...

"Mano" wrote in message
...
OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having to
reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new
devices etc and its happened day and night so its not something we are
manually turning on or off.

any ideas where to start ?

Switch off individual breakers and see when/ if the problem goes away.
After determining the circuit at fault you can then isolate individual
appliances on that circuit until you isolate one that causes the problem
to go away. You then attend to that appliance. If you can identify an
individual circuit that has problems but no appliance has a problem, then
you have wiring/ wiring fitting problems.

If the problem doesn't go away at all using any of the checks above you
then, most probably, have a defective MCB.

I think you may have some confusion between the function of an mcb and
that of an rcd. The mcb will trip if the circuit current exceeds the value
quoted on the mcb, whereas the rcd will trip if the difference in the
current flowing in the live and neutral conductors exceeds a minimal
value, normally 30 mA (30 thousandths of an ampere). The two devices are
intended to protect you against rather different circuit faults and may
well be protecting you against fire at this very moment.

Call in a qualified electrician and get it sorted! Don't do any nasty
desperate bodges!
Sorry, end of paragraph 2 should read................, have a defective RCD

[Graham.]

"Mano" wrote in message
...
OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having to
reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new devices
etc and its happened day and night so its not something we are manually
turning on or off.

any ideas where to start ?


Not strange, in fact a common problem.
Search this group for RCD nuisance trip
Start by unplugging all non essential earthed
appliances and see if it stops.
Tripping individual MCBs and waiting a few hours might
eliminate those circuits, but then again it might not
if the leakage is neutral to earth.
Sometimes its not just one appliance, its the combination
of several small earth leakages that trips the RCD.
Particularly suspect anything that is closely associated with water
Kettles
CH water pumps
Junction boxes exposed to the elements
--
Graham

%Profound_observation%

[Andy Wade]

Tuthledeen wrote:
"Mano" wrote in message
...
OK open to ideas here with this one :-

Switch off individual breakers and see when/ if the problem goes away. [...]

If the problem doesn't go away at all using any of the checks above you
then, most probably, have a defective MCB.

Not necessarily true. A neutral-earth short anywhere in the
installation (or an appliance) could cause the reported symptoms.
Isolating individual final circuits would not help in this case, unless
the OP has double-pole MCBs (unlikely).

I think you may have some confusion between the function of an mcb and that
of an rcd.

So do you, judging by your reply above. Anyway it's fairly rare for
RCDs to become defective and when they do fail they tend to become
insensitive, or won't trip at all, rather then becoming over-sensitive.

A faulty appliance is the most likely cause. Start with washing
machine, dishwasher, fridge & freezer (esp. if frost-free type),
immersion heater, toaster. Unplug or isolate these completely, such
that the neutral is disconnected too.

--
Andy

[Mogga]

On Sun, 25 Nov 2007 15:11:48 GMT, Mano wrote:

OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having
to reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new
devices etc and its happened day and night so its not something we are
manually turning on or off.

any ideas where to start ?


Have you got a dishwasher? Ours had something go wrong with it
recently and three times had tripped the main RCD - leaving a smell of
"burnt" in the kitchen briefly.
We'd suspected it might be dishwasher as it'd been finished but still
on twice so put the garden RCD onto the plug. Third time it went that
RCD had tripped as well as the main house one so BF's dad had a look
(ex-repairman) and spotted the problem. Couple of quid for a new bit a
interference suppression capacitor thats on the mains side of the
switch and so didn't matter if the dishwasher was on or off (as it was
the last time) as it had arced across.
--
http://www.orderonlinepickupinstore.co.uk
Ah fetch it yourself if you can't wait for delivery
http://www.freedeliveryuk.co.uk
Or get it delivered for free

[Mano]

Andy Wade wrote:
Tuthledeen wrote:
"Mano" wrote in message
...
OK open to ideas here with this one :-

Switch off individual breakers and see when/ if the problem goes away.
[...]

If the problem doesn't go away at all using any of the checks above
you then, most probably, have a defective MCB.

Not necessarily true. A neutral-earth short anywhere in the
installation (or an appliance) could cause the reported symptoms.
Isolating individual final circuits would not help in this case, unless
the OP has double-pole MCBs (unlikely).

I think you may have some confusion between the function of an mcb and
that of an rcd.

So do you, judging by your reply above. Anyway it's fairly rare for
RCDs to become defective and when they do fail they tend to become
insensitive, or won't trip at all, rather then becoming over-sensitive.

A faulty appliance is the most likely cause. Start with washing
machine, dishwasher, fridge & freezer (esp. if frost-free type),
immersion heater, toaster. Unplug or isolate these completely, such
that the neutral is disconnected too.

Ok all thanks for the ideas is switching of a circuit at the MCB enough
to issoloate everything on that leg or not I am suspicious of a freezer
in the garage but having turned off the seperate consumer panel there
had discounted that are we now saying I should have unplugged the
freezer to test this idea?

[Peter Scott]

Mogga wrote:
On Sun, 25 Nov 2007 15:11:48 GMT, Mano wrote:

OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having
to reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new
devices etc and its happened day and night so its not something we are
manually turning on or off.

any ideas where to start ?


Have you got a dishwasher? Ours had something go wrong with it
recently and three times had tripped the main RCD - leaving a smell of
"burnt" in the kitchen briefly.
We'd suspected it might be dishwasher as it'd been finished but still
on twice so put the garden RCD onto the plug. Third time it went that
RCD had tripped as well as the main house one so BF's dad had a look
(ex-repairman) and spotted the problem. Couple of quid for a new bit a
interference suppression capacitor thats on the mains side of the
switch and so didn't matter if the dishwasher was on or off (as it was
the last time) as it had arced across.


Computers and related equipment can cause problems. UPSs as well. Have
you recently got a new PC?

Peter Scott

[Derek Geldard]

On Sun, 25 Nov 2007 16:24:42 +0000, Mogga
wrote:


Have you got a dishwasher?

Or a washing machine ?

Ours had something go wrong with it
recently and three times had tripped the main RCD - leaving a smell of
"burnt" in the kitchen briefly.
We'd suspected it might be dishwasher as it'd been finished but still
on twice so put the garden RCD onto the plug. Third time it went that
RCD had tripped as well as the main house one so BF's dad had a look
(ex-repairman) and spotted the problem. Couple of quid for a new bit a
interference suppression capacitor thats on the mains side of the
switch and so didn't matter if the dishwasher was on or off (as it was
the last time) as it had arced across.

It's a very common failure. Usually the capacitor is integral with a
couple of inductors potted in a metal can to make a filter. Washing
type machines draw a high current, the inductors heat up the capacitor
and shorten it's life. It seems to be difficult to make a reliable one
to fit in the small space they've got at the price they want to pay.

DG

[John Rumm]

Mano wrote:

any ideas where to start ?

He

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


--
Cheers,

John.

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

[Graham.]

"Mano" wrote in message
...
Andy Wade wrote:
Tuthledeen wrote:
"Mano" wrote in message
...
OK open to ideas here with this one :-

Switch off individual breakers and see when/ if the problem goes away.
[...]

If the problem doesn't go away at all using any of the checks above you
then, most probably, have a defective MCB.

Not necessarily true. A neutral-earth short anywhere in the installation
(or an appliance) could cause the reported symptoms. Isolating individual
final circuits would not help in this case, unless the OP has double-pole
MCBs (unlikely).

I think you may have some confusion between the function of an mcb and
that of an rcd.

So do you, judging by your reply above. Anyway it's fairly rare for RCDs
to become defective and when they do fail they tend to become
insensitive, or won't trip at all, rather then becoming over-sensitive.

A faulty appliance is the most likely cause. Start with washing machine,
dishwasher, fridge & freezer (esp. if frost-free type), immersion heater,
toaster. Unplug or isolate these completely, such that the neutral is
disconnected too.

Ok all thanks for the ideas is switching of a circuit at the MCB enough to
issoloate everything on that leg or not I am suspicious of a freezer in
the garage but having turned off the seperate consumer panel there had
discounted that are we now saying I should have unplugged the freezer to
test this idea?


If you switched off the main switch in the garage CU (double pole)
then you have eliminated everything fed off it.

--
Graham

%Profound_observation%

[Bob Eager]

On Sun, 25 Nov 2007 15:44:31 UTC, "Graham." wrote:

Particularly suspect anything that is closely associated with water
Kettles
CH water pumps
Junction boxes exposed to the elements

And immersion heater, if you have one. A previous house of ours had a
corroded immersion heater and it did just this (as it should).
--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

[Mano]

Bob Eager wrote:
On Sun, 25 Nov 2007 15:44:31 UTC, "Graham." wrote:

Particularly suspect anything that is closely associated with water
Kettles
CH water pumps
Junction boxes exposed to the elements

And immersion heater, if you have one. A previous house of ours had a
corroded immersion heater and it did just this (as it should).

Interesting option we do have one but its turned off never used. Does
that rule it out ?

[Mogga]

On Sun, 25 Nov 2007 21:11:55 GMT, Mano wrote:

Bob Eager wrote:
On Sun, 25 Nov 2007 15:44:31 UTC, "Graham." wrote:

Particularly suspect anything that is closely associated with water
Kettles
CH water pumps
Junction boxes exposed to the elements

And immersion heater, if you have one. A previous house of ours had a
corroded immersion heater and it did just this (as it should).

Interesting option we do have one but its turned off never used. Does
that rule it out ?

Our dishwasher was plugged in "on" at the wall but not actually on at
the machine...
--
http://www.orderonlinepickupinstore.co.uk
Ah fetch it yourself if you can't wait for delivery
http://www.freedeliveryuk.co.uk
Or get it delivered for free

[Bob Eager]

On Sun, 25 Nov 2007 21:11:55 UTC, Mano wrote:

Bob Eager wrote:
On Sun, 25 Nov 2007 15:44:31 UTC, "Graham." wrote:

Particularly suspect anything that is closely associated with water
Kettles
CH water pumps
Junction boxes exposed to the elements

And immersion heater, if you have one. A previous house of ours had a
corroded immersion heater and it did just this (as it should).

Interesting option we do have one but its turned off never used. Does
that rule it out ?

Depends, I guess. But they usually have a double pole switch, which
*would* rule it out completely.
--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

[Graham.]

"Bob Eager" wrote in message
...
On Sun, 25 Nov 2007 15:44:31 UTC, "Graham." wrote:

Particularly suspect anything that is closely associated with water
Kettles
CH water pumps
Junction boxes exposed to the elements

And immersion heater, if you have one. A previous house of ours had a
corroded immersion heater and it did just this (as it should).
--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

The most memorable earth leakage problem that I have delt
with was when a column of ants decided to march into my
central heating wiring centre (actually just a JB). I eventually
found a number of them fused together forming a bridge
between L&E. Took me quite some time to find it though.
--
Graham

%Profound_observation%

[Mike Harrison]

On Sun, 25 Nov 2007 15:32:32 -0000, "Tuthledeen" wrote:


"Mano" wrote in message
...
OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having to
reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new devices
etc and its happened day and night so its not something we are manually
turning on or off.

any ideas where to start ?

Switch off individual breakers and see when/ if the problem goes away. After
determining the circuit at fault you can then isolate individual appliances
on that circuit until you isolate one that causes the problem to go away.
You then attend to that appliance. If you can identify an individual circuit
that has problems but no appliance has a problem, then you have wiring/
wiring fitting problems.

Bear in mind that this will not catch a neutral-to-earth fault though. If the RCD is tripping with
no other signs of problems ( bangs etc.!) , N-to-E shorting somewhere is a distinct possibility

[cj]

Hi
Re the problem check the fridge. freezer .Pains in the backside for this
kind of tripping when getting older ,everytime the compressor starts out
goes the breaker.

As for strange had similar problems with ants in a call system last year
,took ages to trace .Seems they liked the junction box as a nest.

CJ

[Mano]

Mano wrote:
OK open to ideas here with this one :-

we have a mcb style mains board (crabtree from memory) which has an RCD
device built in. Normally when when for an example a bulb goes the trip
for that lighting circuit goes bit of a pain but we can live with it.
However yesterday and today has been a nightmare with the main breaker
tripping on average every two hours! No individual circuit goes and
throwing the break brings everything back to normal (apart from having
to reset the times on the cooker microwave stero etc!).

At a loss for any ideas. Nothing has changed regarding load no new
devices etc and its happened day and night so its not something we are
manually turning on or off.

any ideas where to start ?


Ok for completion went round unplugging all none essential items which
stopped the tripping re-introduced one at a time over a few days. Proved
to be a combination of a deep fat frier (pluged in turned off) and
microwave when in the same double socket. different sockects cleared it!
wouldnt mind but the deep fat frier was borrowed to test a new recipe
and I didnt like it anyway!

[Dave Plowman (News)]

In article ,
Mano wrote:
Ok for completion went round unplugging all none essential items which
stopped the tripping re-introduced one at a time over a few days. Proved
to be a combination of a deep fat frier (pluged in turned off) and
microwave when in the same double socket. different sockects cleared it!
wouldnt mind but the deep fat frier was borrowed to test a new recipe
and I didnt like it anyway!

Deep fat friers usually have a mineral insulated element rather like an
immersion heater and a prime candidate for leaking to earth while still
working.

--
*I finally got my head together, now my body is falling apart.

Dave Plowman London SW
To e-mail, change noise into sound.