Apologies in advance for length of post.

As part of our nearly-complete building work, the old fuseboard (as I
still call it) was replaced by an all-singing, all-dancing consumer
unit. Whizzo, I thought, as I recalled our last house where every
time a light bulb blew the consumer unit arranged for the whole house
to be plunged into darkness and a joyous festival of resetting the
blinking 12:00s was on the cards.

The new unit behaves differently, but it does have one very, very
annoying habit. Every so often without any rhyme or reason that I can
tell, part of the thing trips and all the sockets in the house go
dead. The lights are fine, but nothing else. I asked the electrician
to test it, but he simply suggested unplugging things until it stops
happening. Yet more blinking 12:00s to play with.

Fine, except that it might happen four times in one day, and then not
happen again for three days, whereupon it might happen another six
times in three hours.

We recently went away for a week and fretted about this happening ten
minutes after driving away and all the food in the fridge spoiling, so
we unplugged everything and switched everything off except the fridge,
the DVD recorder and one or two other essentials. When we got back
everything was fine, no power outages (as the Merkins have it), and
gradually we plugged things back in and switched things back on as and
when required. And it all seemed fine for a few days, and then
suddenly they all went off again and the whole merry cycle began anew.

The only appliances that are running 24/7 are fridge, cookers (well,
the clocks anyhow), alarm clocks and whatever controls the boiler.
Plenty of other appliances are plugged in, and on at the wall, but not
in use (washing machine, dishwasher, TV (never left on standby) etc.
etc).

I don't have the correct terms for all the bits and bobs of the
consumer unit, but it's divided into two rows of eight trips (what
would, I suppose, have been fuses in the old days, what I think are
now called MCBs) with each row having a master "trip" (an RCD?) and an
over-arching master "trip" (a super RCD?) for the whole shooting
match.

It's the lower master "trip" that trips - the one controlling the
second row of individual trips. These trips are labelled "Hob",
"Sockets - kitchen", "Sockets - Upstairs", "Sockets - Garage",
"Sockets - Extension", "Immersion Heater", "Cooker", "Hall/Lounge
sockets downstairs".

Given that the rate of failure is so low and MTBF so long (for
elimination purposes), and that the sub-master trip is what goes
(rather than the individual trip for the misperforming part of the
system), which doesn't exactly narrow possibilities down, does anyone
have any ideas how we could go about finding the problem? Electrician
thinks the prime candidate is the fridge, which is the one thing that
we can't realistically turn off and see if everything carries on
working (plus it didn't trip for the 9 days we were away). Would
using an RCD on the fridge tell us anything - such as this

http://www.maplin.co.uk/Module.aspx?...FQaLEgodbE-F2g

http://tinyurl.com/26zt6u?

Could it be a fault in the consumer unit itself?

Thanks

Edward

teddysnips ) gurgled happily, sounding much like
they were saying:

It's the lower master "trip" that trips - the one controlling the second
row of individual trips. These trips are labelled "Hob", "Sockets -
kitchen", "Sockets - Upstairs", "Sockets - Garage", "Sockets -
Extension", "Immersion Heater", "Cooker", "Hall/Lounge sockets
downstairs".

Given that the rate of failure is so low and MTBF so long (for
elimination purposes), and that the sub-master trip is what goes (rather
than the individual trip for the misperforming part of the system),

Silly question - it couldn't just be being overloaded, could it? What
rating's that master got, and what's the sum of the ratings below it?

On Feb 15, 2:41*pm, wrote:
off and see if everything carries on
working (plus it didn't trip for the 9 days we were away). *Would
using an RCD on the fridge tell us anything - such as this

http://www.maplin.co.uk/Module.aspx?...W&Criteria=rcd...

http://tinyurl.com/26zt6u?

Could it be a fault in the consumer unit itself?

Thanks

Edward

If you're not worried that there's an actual hazardous fault anywhere
then you could move a circuit from the RCD side to the non-RCD side,
perhaps starting with the fridge circuit. (It sounds like you have a
split load unit - sockets on the RCD, lights on the non-RCD)

The consumer unit is just a box of components so I guess it could be a
particular component in there isn't right.

On 15 Feb, 14:50, adder1969 wrote:
On Feb 15, 2:41*pm, wrote:
*off and see if everything carries on

working (plus it didn't trip for the 9 days we were away). *Would
using an RCD on the fridge tell us anything - such as this

http://www.maplin.co.uk/Module.aspx?...W&Criteria=rcd...

http://tinyurl.com/26zt6u?

Could it be a fault in the consumer unit itself?

Thanks

Edward

If you're not worried that there's an actual hazardous fault anywhere
then you could move a circuit from the RCD side to the non-RCD side,
perhaps starting with the fridge circuit. *(It sounds like you have a
split load unit - sockets on the RCD, lights on the non-RCD)

The consumer unit is just a box of components so I guess it could be a
particular component in there isn't right.

I'm not worried that there's an actual hazardous fault anywhere, but
that's only because none of us has been electrocuted recently. I
think you're right, we do have a split load circuit. Presumably it's
an electrician's job to do the circuit moving as you suggest?

Thanks

Edward

On 15 Feb, 14:46, Adrian wrote:
teddysnips ) gurgled happily, sounding much like
they were saying:

It's the lower master "trip" that trips - the one controlling the second
row of individual trips. *These trips are labelled "Hob", "Sockets -
kitchen", "Sockets - Upstairs", "Sockets - Garage", "Sockets -
Extension", "Immersion Heater", "Cooker", "Hall/Lounge sockets
downstairs".

Given that the rate of failure is so low and MTBF so long (for
elimination purposes), and that the sub-master trip is what goes (rather
than the individual trip for the misperforming part of the system),

Silly question - it couldn't just be being overloaded, could it? What
rating's that master got, and what's the sum of the ratings below it?

Not at all a silly question - I'll take a look when I get home.
Thanks

Edward

It sounds like you're describing an RCD tripping on a split load
consumer unit (post a pic so we can verify this). Does the switch that
trips say something like "30mA" and have a test button it?

As your electrician says, it's probably a faulty appliance that's
passing a little too much earth leakage - combined with the small
allowable leakages that is normal with many appliances.

wrote in message
...
We recently went away for a week and fretted about this happening ten
minutes after driving away and all the food in the fridge spoiling, so
we unplugged everything and switched everything off except the fridge,
the DVD recorder and one or two other essentials. When we got back
everything was fine, no power outages (as the Merkins have it), and
gradually we plugged things back in and switched things back on as and
when required. And it all seemed fine for a few days, and then
suddenly they all went off again and the whole merry cycle began anew.

The only appliances that are running 24/7 are fridge, cookers (well,
the clocks anyhow), alarm clocks and whatever controls the boiler.
Plenty of other appliances are plugged in, and on at the wall, but not
in use (washing machine, dishwasher, TV (never left on standby) etc.
etc).

I don't have the correct terms for all the bits and bobs of the
consumer unit, but it's divided into two rows of eight trips (what
would, I suppose, have been fuses in the old days, what I think are
now called MCBs) with each row having a master "trip" (an RCD?) and an
over-arching master "trip" (a super RCD?) for the whole shooting
match.

It's the lower master "trip" that trips - the one controlling the
second row of individual trips. These trips are labelled "Hob",
"Sockets - kitchen", "Sockets - Upstairs", "Sockets - Garage",
"Sockets - Extension", "Immersion Heater", "Cooker", "Hall/Lounge
sockets downstairs".


The system designer (your electrician?) hasn't done you any favours if he
didn't ask if you ask if you wanted your freezer on a dedicated circuit,
ditto your boiler, though where that is connected is not clear. For little
extra cost you could have had a RCBO for each socket ring, the garage on non
sockets RCD but RCD'd in the garage. Can't undrerstand the Immersion Heater
being on a sockets RCD either. Ditto cooker and hob unless there is a
control unit socket. Find out why the electrician did it this way and
maybe think about a different electrician.

Jim A

In message
,
" writes

It sounds like you're describing an RCD tripping on a split load
consumer unit (post a pic so we can verify this). Does the switch that
trips say something like "30mA" and have a test button it?

As your electrician says, it's probably a faulty appliance that's
passing a little too much earth leakage - combined with the small
allowable leakages that is normal with many appliances.

Dishwasher.

In my case, heater element, although I am concerned about steam getting
places it shouldn't via the bottom door seal.

regards

--
Tim Lamb

wrote:


The new unit behaves differently, but it does have one very, very
annoying habit. Every so often without any rhyme or reason that I can
tell, part of the thing trips and all the sockets in the house go
dead. The lights are fine, but nothing else. I asked the electrician
to test it, but he simply suggested unplugging things until it stops
happening. Yet more blinking 12:00s to play with.

It sounds like you have a nuisance trip issue with a split load CU. This
is not common, can happen and is as you have discovered a pain to fix!

Of the two "master" trips to which you refer, chances are one is just a
main switch, and the other is the RCD (you can have RCDs in both
positions but that is currently not that common unless you are out in
the sticks).

A photo would be handy.

Fine, except that it might happen four times in one day, and then not
happen again for three days, whereupon it might happen another six
times in three hours.

Tracking the cause of these trips can be time consuming. You can read
some background on the subject he

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

I don't have the correct terms for all the bits and bobs of the
consumer unit, but it's divided into two rows of eight trips (what
would, I suppose, have been fuses in the old days, what I think are
now called MCBs) with each row having a master "trip" (an RCD?) and an
over-arching master "trip" (a super RCD?) for the whole shooting
match.

Your naming sounds about right. The "super" RCD may just be a switch as
mentioned before.

It's the lower master "trip" that trips - the one controlling the
second row of individual trips. These trips are labelled "Hob",
"Sockets - kitchen", "Sockets - Upstairs", "Sockets - Garage",
"Sockets - Extension", "Immersion Heater", "Cooker", "Hall/Lounge
sockets downstairs".

It sounds like there are some design failings to be addressed there -
the arrangement of circuits is not ideal with various things that
represent low electrocutions risk, but high nuisance trip risk being
connected to the RCD side of the CU.

Given that the rate of failure is so low and MTBF so long (for
elimination purposes), and that the sub-master trip is what goes
(rather than the individual trip for the misperforming part of the
system), which doesn't exactly narrow possibilities down, does anyone
have any ideas how we could go about finding the problem? Electrician

The individual trips will only trip under different circumstances anyway
- when something draws too much current. The RCD trip results from a
different cause.

thinks the prime candidate is the fridge, which is the one thing that
we can't realistically turn off and see if everything carries on
working (plus it didn't trip for the 9 days we were away). Would
using an RCD on the fridge tell us anything - such as this

Not really - even if it was the main source of leakage it might not on
its own cause a trip.

http://www.maplin.co.uk/Module.aspx?...FQaLEgodbE-F2g

http://tinyurl.com/26zt6u?

Could it be a fault in the consumer unit itself?

Not very likely. It could just be a fault in the house wiring though.
(e.g. neutral to earth short)

--
Cheers,

John.

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

On Fri, 15 Feb 2008 07:14:21 -0800 (PST),
wrote:

On 15 Feb, 14:50, adder1969 wrote:
On Feb 15, 2:41*pm, wrote:
*off and see if everything carries on

working (plus it didn't trip for the 9 days we were away). *Would
using an RCD on the fridge tell us anything - such as this

http://www.maplin.co.uk/Module.aspx?...W&Criteria=rcd...

http://tinyurl.com/26zt6u?

Could it be a fault in the consumer unit itself?

Thanks

Edward

If you're not worried that there's an actual hazardous fault anywhere
then you could move a circuit from the RCD side to the non-RCD side,
perhaps starting with the fridge circuit. *(It sounds like you have a
split load unit - sockets on the RCD, lights on the non-RCD)

The consumer unit is just a box of components so I guess it could be a
particular component in there isn't right.

I'm not worried that there's an actual hazardous fault anywhere, but
that's only because none of us has been electrocuted recently. I
think you're right, we do have a split load circuit. Presumably it's
an electrician's job to do the circuit moving as you suggest?

Thanks

Edward

We had problems with random tripping and it turned out to be a bit of
the dishwasher causing it. Even when it was just plugged in and not in
use. Sussed it cos of a bit of burnt electrical smell in the kitchen
which narrowed it down. Bits been replaced now and problem solved.
--
http://www.freedeliveryuk.co.uk

In article ,
writes:
On 15 Feb,
"Jim Alexander" wrote:

The system designer (your electrician?) hasn't done you any favours if he
didn't ask if you ask if you wanted your freezer on a dedicated circuit,
ditto your boiler, though where that is connected is not clear. For little
extra cost you could have had a RCBO for each socket ring, the garage on
non sockets RCD but RCD'd in the garage. Can't undrerstand the Immersion
Heater being on a sockets RCD either. Ditto cooker and hob unless there
is a control unit socket. Find out why the electrician did it this way
and maybe think about a different electrician.

I'd rather put the boiler on the RCD side, that way when you have the
(inevitable) leak into the electrics it trips /before/ it burns anything up,
and also gives an earlier of a problem.

The problem is that tripping by something else would leave the house
without frost protection, which would could be a serious disaster if
you are away at the time.

If you really want an RCD protected boiler, I would ensure it is
dedicated -- easiest way is probably an RCD protected spur on a
non-protected circuit.

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

On Sat, 16 Feb 2008 09:49:44 +0000, Andrew Gabriel wrote:

snip

If you really want an RCD protected boiler, I would ensure it is
dedicated -- easiest way is probably an RCD protected spur on a
non-protected circuit.


Also, there is no need for a 30mA sensitivity RCD in this case. You could
use a much less sensitive device.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net

In article ,
mick writes:
On Sat, 16 Feb 2008 09:49:44 +0000, Andrew Gabriel wrote:

snip

If you really want an RCD protected boiler, I would ensure it is
dedicated -- easiest way is probably an RCD protected spur on a
non-protected circuit.

Also, there is no need for a 30mA sensitivity RCD in this case. You could
use a much less sensitive device.

There's no need for the RCD at all. However, the reason B Thumbs
gave for wanting might not be satisfied with a higher current one.

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

On Feb 15, 2:41*pm, wrote:

[original post snipped]

Here are photos of the misperforming parts.

The whole consumer unit is he

http://i250.photobucket.com/albums/g...e/100_1145.jpg

The strip that fails is he

http://i250.photobucket.com/albums/g...e/100_1146.jpg

The button that flips up is on the far left.

Thanks again everybody.

Edward

wrote:
On Feb 15, 2:41 pm, wrote:

[original post snipped]

Here are photos of the misperforming parts.

The whole consumer unit is he

http://i250.photobucket.com/albums/g...e/100_1145.jpg

The strip that fails is he

http://i250.photobucket.com/albums/g...e/100_1146.jpg

The button that flips up is on the far left.

Thanks again everybody.

Edward

Yup. classic piece of regulatory ****e.

So did mine till `I put in a 100mA trip for the whole house.

I recommend you do teh same, and then fit RCBO's to the circuits that
need them - typically IIRC those with outside sockets.

100mA is abit on the high side to stop you being electrocuted when
grabbing e.g. a live light fitting,but if you are already marginal due
to earth leakage from multifarious RFI filters in the computers, TVS,
radios and all the other gubbins one has, in reality its only 60mA
more..and will trip if you have a serious earth fault. Then stay legal
with RCBO's on the places that really need them.

The message

from contains these words:

On Feb 15, 2:41*pm, wrote:

[original post snipped]

Here are photos of the misperforming parts.

The whole consumer unit is he

http://i250.photobucket.com/albums/g...e/100_1145.jpg

The strip that fails is he

http://i250.photobucket.com/albums/g...e/100_1146.jpg

The button that flips up is on the far left.

Thanks again everybody.

Edward


Photo's not too clear. Looks like a Chint box, but they usually have
translucent covers to the breakers. So what make is it?

30mA trip and you've got the hob, cooker and immersion heater on it?
Recipe for frequent tripping. As has been suggested, the very LEAST you
should do is swop that trip for a 100mA one.

You may actually be able to use a split busbar in that box, in which
case you could fit a switch-disconnect at the other end of the same row
and cut the busbar appropriately.

And there's actually a spare way in the top row of breakers which are on
a switch-disconnect.

wrote:
On Feb 15, 2:41�pm, wrote:

[original post snipped]

Here are photos of the misperforming parts.

The whole consumer unit is he

http://i250.photobucket.com/albums/g...e/100_1145.jpg

The strip that fails is he

http://i250.photobucket.com/albums/g...e/100_1146.jpg

The button that flips up is on the far left.

Thanks again everybody.

Edward

RCCB = RCD, and I gather that's whats tripping. The problem is
RCD nuisance tripping. The wiki article John pointed to would be a
start. In short there are probably 2 issues:
1. You've got a lot of equipment on the RCD that shouldnt really be
on it, and that makes your setup liable to these kind of problems.
Its not verboten to have it this way, but it is a recipe for nuisance
trips.
2. Some appliance somewhere may be electrically slightly leaky -
but with all that kit on one RCD that isnt necessarily so, the setup
is a bad design.

Solutions:
1. Resistance test all appliances, from E to L+N. A multimeter will
do for a start, they arent perfect but usually pick up the offender
if
there is one. Write down all the R readings, and the lowest Rs are
your prime suspects. Theres a fairly good likelihood this will solve
the current problem - but you will still be left with an installation
where this is liable to recur in future.
2. Reconfigure your CU layout to move items that dont need to be
on an RCD to the other non-RCD supply.
3. It is possible as an alternative to change the RCD and MCBs,
but depending on the details this will either breach regs or be
costly.
9x RCBOs = about £300.

A separate electrical feed for the f/f would have been a good idea,
preferably not from the RCD, but if the decor's all finished its poor
timing to put one in now.


NT

wrote:

The whole consumer unit is he

http://i250.photobucket.com/albums/g...e/100_1145.jpg

The strip that fails is he

http://i250.photobucket.com/albums/g...e/100_1146.jpg

The button that flips up is on the far left.

OK this makes it clearer. Looks like you have your "split load" consumer
unit built up from two different CUs. With the lower one being RCD
protected and the top one just having a simple switch (which I presume
also cuts power to the whole lower CU as well).

There are a number of circuits on the CU that are known to be potential
causes of trouble: The hob, cooker, & immersion heater. Moving those to
the top CU might be better (you would need to combine a couple of
circuits on the top one to make space since you only have one free way
up there). Having said that there are many people with "whole house"
RCDs feeding many more circuits than that without any problem. So while
an appliance fault is the most likely scenario, don't assume that the
cause of the trip is minor and should be ignored.

Other than that, your best line of approach is following the fault
finding section in the wiki article.

--
Cheers,

John.

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

The message
from John Rumm contains these words:

wrote:

The whole consumer unit is he

http://i250.photobucket.com/albums/g...e/100_1145.jpg

The strip that fails is he

http://i250.photobucket.com/albums/g...e/100_1146.jpg

The button that flips up is on the far left.

OK this makes it clearer. Looks like you have your "split load" consumer
unit built up from two different CUs.

I think that though it looks as if it makes use of some of the tooling
and components for separate CUs it's actually one phsyical plastic box.
We'd be a lot further on if the OP will just tell us what make it is.
My guess is it's Chinese and probably a Chint or clone of one.

With the lower one being RCD
protected and the top one just having a simple switch (which I presume
also cuts power to the whole lower CU as well).

Possibly -- but it might well be a simple split unit with the RCD for
the entire lower busbar fed from live side of switch disconnect.

There are a number of circuits on the CU that are known to be potential
causes of trouble: The hob, cooker, & immersion heater. Moving those to
the top CU might be better (you would need to combine a couple of
circuits on the top one to make space since you only have one free way
up there).

Agreed as to the most probable sources of trouble, especially with a
30mA RCD. However there are two spare ways in the bottom so there's
room to put in a second switch-disconnect and split the busbar in the
bottom row, always assuming that parts to fit are available.

If only the OP would come back with a bit more info.

On Feb 20, 10:42*pm, Appin wrote:

[...]

If only the OP would come back with a bit more info.

I've looked and failed to find a make for the CU. All I can find is a
logo, which looks like a box containing an ellipse containing a
triangle pointing to the right:
____
[ ( |) ]

Best picture I could muster he

http://i250.photobucket.com/albums/g.../hazy_logo.jpg

I've looked on the web for an example of a Chint logo but couldn't
find one.

I've tried turning off the dishwasher (an early candidate) - it has a
switch on the wall in place of a plug but there was another trip so I
presume that I can rule out the dishwasher?

The overall box is a single moulded piece of plastic, and the items
inside are modular. I could take the cover off (possibly) and take
more pictures, but I don't have any confidence in staying alive during
this proceeding.

Better pictures of the top row of switches he

http://i250.photobucket.com/albums/g...OfTime/top.jpg

And the bottom row again.

http://i250.photobucket.com/albums/g...ime/bottom.jpg

There's also this box thing attached to the top of the unit. I think
it's something to do with the doorbell.

http://i250.photobucket.com/albums/g...box_on_top.jpg

Thanks - any further thoughts?

Edward

wrote in message
...
On Feb 20, 10:42 pm, Appin wrote:

[...]

If only the OP would come back with a bit more info.

I've looked and failed to find a make for the CU. All I can find is a
logo, which looks like a box containing an ellipse containing a
triangle pointing to the right:
____
[ ( |) ]

Best picture I could muster he

http://i250.photobucket.com/albums/g.../hazy_logo.jpg

I've looked on the web for an example of a Chint logo but couldn't
find one.

I've tried turning off the dishwasher (an early candidate) - it has a
switch on the wall in place of a plug but there was another trip so I
presume that I can rule out the dishwasher?

The overall box is a single moulded piece of plastic, and the items
inside are modular. I could take the cover off (possibly) and take
more pictures, but I don't have any confidence in staying alive during
this proceeding.

Better pictures of the top row of switches he

http://i250.photobucket.com/albums/g...OfTime/top.jpg

And the bottom row again.

http://i250.photobucket.com/albums/g...ime/bottom.jpg

There's also this box thing attached to the top of the unit. I think
it's something to do with the doorbell.

http://i250.photobucket.com/albums/g...box_on_top.jpg

Thanks - any further thoughts?

Google "DZ47" and you will learn something to your advantage.

But to get back to your problem, I don't think the make is as important as
the system design issues alluded to by several people here but which you
don't yet seem to have acknowledged.

Jim A

On 23 Feb, 20:43, "Jim Alexander" wrote:

[...]

Google "DZ47" and you will learn something to your advantage.

I didn't. What exactly do you think I might learn that would be to my
advantage?

But to get back to your problem, I don't think the make is as important as
the system design issues alluded to by several people here but which you
don't yet seem to have acknowledged.

It's not that I haven't acknowledged it, it's just that I haven't the
faintest idea what they're talking about! Seriously, electrics is a
Black Art as far as I'm concerned. I originally posted hoping someone
would give me a few steps that I could take to locate the problem. As
the thread has gone on, it's become increasingly clear that there may
be any number of possible solutions, almost none of which I am
personally competent to pursue.

Edward

The message

from contains these words:

On 23 Feb, 20:43, "Jim Alexander" wrote:

[...]

Google "DZ47" and you will learn something to your advantage.

I didn't. What exactly do you think I might learn that would be to my
advantage?

But to get back to your problem, I don't think the make is as important as
the system design issues alluded to by several people here but which you
don't yet seem to have acknowledged.

It's not that I haven't acknowledged it, it's just that I haven't the
faintest idea what they're talking about! Seriously, electrics is a
Black Art as far as I'm concerned. I originally posted hoping someone
would give me a few steps that I could take to locate the problem. As
the thread has gone on, it's become increasingly clear that there may
be any number of possible solutions, almost none of which I am
personally competent to pursue.

Edward

I think there's general agreement that your consumer unit has been wired
in a less-than-dieal way.

It's possible to change the way it's wired in order to minimise the
possiblity of nuisance trips and limit the damage they can cause.

Although your box does not appear to be a current-production Chint,
everything about it seems to indicate Chinese -- though that's not a
negative thing at all.

Since you don't have the expertise to put into practice the suggestions
re your consumer unit, you're going to have to call in an electrician to
make sure that the cooker, hob nad water heater are no longer on an RCD
and that the 30mA RCD is changed for a 100mA RCD. That las change
alone might remove the nuisance tripping.

wrote:

It's not that I haven't acknowledged it, it's just that I haven't the
faintest idea what they're talking about! Seriously, electrics is a
Black Art as far as I'm concerned. I originally posted hoping someone
would give me a few steps that I could take to locate the problem. As
the thread has gone on, it's become increasingly clear that there may
be any number of possible solutions, almost none of which I am
personally competent to pursue.

To be fair, most of anything we could cover here is spelt out in detail
in the nuisance trip section of the wiki on RCDs.

http://wiki.diyfaq.org.uk/index.php?title=RCD

and specifically:

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

We wrote this article because the problem you have does come up from
time to time, and tracing and rectifying it can be difficult.

Perhaps a more workable way forward is for you to read through the
article and come back with specific questions that it raises, or
highlight any bits that you don't understand. That way we can either
explain or improve the descriptions in the wiki.

Part of the difficulty here is that the problem you are trying to solve
may be caused by something quite subtle and the cause of it may be
complex to understand especially without some background knowledge. Once
you have run through the empirical tests in the fault finding section
you get into the more difficult tests that involve opening your consumer
unit and using test equipment. If you do not feel that you can do this
safely then it is time to hand over to someone else. However if you can
start by eliminating a number of likely causes you will make the task
easier for them (and cheaper for you)

--
Cheers,

John.

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

Appin wrote:

Since you don't have the expertise to put into practice the suggestions
re your consumer unit, you're going to have to call in an electrician to
make sure that the cooker, hob nad water heater are no longer on an RCD
and that the 30mA RCD is changed for a 100mA RCD. That las change
alone might remove the nuisance tripping.

Since the 30mA RCD is the only one, and it offers protection to the
sockets you can't replace it with a 100mA one since this does not
provide the required shock protection.

--
Cheers,

John.

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