A friend of mine has a pond with pump & lights wired into a fused spur from
the house ring-main (which is RCD protected). After some recent heavy rain
(which probably managed to penetrate a supposedly "water-tight" outside
junction-box, the RCD tripped, which wouldn't have been a problem if he
hadn't been away on holiday at the time and the fact that the freezer was on
same circuit.

I wondered about changing the existing fused spur for another RCD (like this
one
http://www.screwfix.com/app/sfd/cat/...00509&id=83049)
but I see that it has the same 30mA trip current as the existing one in the
main fusebox

Would I be right in thinking that this wouldn't necessarily stop the main
fusebox RCD tripping?

Would one with a lower (20mA say) trip current work (and do such things
exist)?

Tim

On Tue, 21 Aug 2007 13:55:12 +0100 someone who may be "Tim Downie"
wrote this:-

A friend of mine has a pond with pump & lights wired into a fused spur from
the house ring-main (which is RCD protected). After some recent heavy rain
(which probably managed to penetrate a supposedly "water-tight" outside
junction-box, the RCD tripped, which wouldn't have been a problem if he
hadn't been away on holiday at the time and the fact that the freezer was on
same circuit. [snip]

Would I be right in thinking that this wouldn't necessarily stop the main
fusebox RCD tripping?

Yes.

Would one with a lower (20mA say) trip current work (and do such things
exist)?

It would work in that it would disconnect the supply. However, it is
likely that the main one would also work.

In this sort of situation you need a time delayed one on the main
board, but this gives rise to other difficulties.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On Tue, 21 Aug 2007 13:55:12 +0100 someone who may be "Tim Downie"
wrote this:-

A friend of mine has a pond with pump & lights wired into a fused
spur from the house ring-main (which is RCD protected). After some
recent heavy rain (which probably managed to penetrate a supposedly
"water-tight" outside junction-box, the RCD tripped, which wouldn't
have been a problem if he hadn't been away on holiday at the time
and the fact that the freezer was on same circuit. [snip]

Would I be right in thinking that this wouldn't necessarily stop
the main fusebox RCD tripping?

Yes.

Would one with a lower (20mA say) trip current work (and do such
things exist)?

It would work in that it would disconnect the supply. However, it is
likely that the main one would also work.

In this sort of situation you need a time delayed one on the main
board, but this gives rise to other difficulties.

Hmm, sounds like it will be easier to wire the pond into a circuit & RCD of
its own. I was hoping for a "lazy-man's" solution. ;-)

Tim

"Tim Downie" wrote in message
...

Hmm, sounds like it will be easier to wire the pond into a circuit & RCD
of its own. I was hoping for a "lazy-man's" solution. ;-)

Isolate pond circuit when going away on holiday?

cheers,
clive

On 21 Aug, 14:33, David Hansen
wrote:
On Tue, 21 Aug 2007 13:55:12 +0100 someone who may be "Tim Downie"
wrote this:-

A friend of mine has a pond with pump & lights wired into a fused spur from
the house ring-main (which is RCD protected). After some recent heavy rain
(which probably managed to penetrate a supposedly "water-tight" outside
junction-box, the RCD tripped, which wouldn't have been a problem if he
hadn't been away on holiday at the time and the fact that the freezer was on
same circuit. [snip]
Would I be right in thinking that this wouldn't necessarily stop the main
fusebox RCD tripping?

Yes.

Would one with a lower (20mA say) trip current work (and do such things
exist)?

It would work in that it would disconnect the supply. However, it is
likely that the main one would also work.

In this sort of situation you need a time delayed one on the main
board, but this gives rise to other difficulties.

....such as the fact that they are scarily expensive. Cheapest I found
was from CPC a couple of years back. £85 + VAT IIRC.

Jon.

On 21 Aug, 15:45, "Clive George" wrote:
"Tim Downie" wrote in message

...

Hmm, sounds like it will be easier to wire the pond into a circuit & RCD
of its own. I was hoping for a "lazy-man's" solution. ;-)

Isolate pond circuit when going away on holiday?

cheers,
clive

Or put the deep freeze on its own unprotected circuit as I have
done.

Interersting post though as my garage, workshop and greenhouse systems
are all on their own rcd's but seperate from the house one.

Rob

robgraham wrote:

Or put the deep freeze on its own unprotected circuit as I have
done.

Interersting post though as my garage, workshop and greenhouse systems
are all on their own rcd's but seperate from the house one.
Same here on both points. Also computer & lan stuff on their own circuit.

On Tue, 21 Aug 2007 15:04:32 +0100, "Tim Downie"
wrote:


Hmm, sounds like it will be easier to wire the pond into a circuit & RCD of
its own. I was hoping for a "lazy-man's" solution. ;-)

Run the pond stuff off a 1:1 isolating transformer (with an RCD on
the secondary if you wish).


--
Peter Parry.
http://www.wpp.ltd.uk/

In article ,
"Tim Downie" writes:
A friend of mine has a pond with pump & lights wired into a fused spur from
the house ring-main (which is RCD protected). After some recent heavy rain
(which probably managed to penetrate a supposedly "water-tight" outside
junction-box, the RCD tripped, which wouldn't have been a problem if he
hadn't been away on holiday at the time and the fact that the freezer was on
same circuit.

You don't want any outdoor circuits sharing an RCD with anything
indoors, for this sort of reason. Also a fridge/freezer is not
something which needs to be RCD protected at all. You have a fault
and the RCD appropriately detected it, but the circuit design for
the property would not appear to limited the effects of that fault
in a desirable way. Both issues need fixing.

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

"robgraham" wrote in message
oups.com...
On 21 Aug, 15:45, "Clive George" wrote:
"Tim Downie" wrote in message

...

Hmm, sounds like it will be easier to wire the pond into a circuit &
RCD
of its own. I was hoping for a "lazy-man's" solution. ;-)

Isolate pond circuit when going away on holiday?

cheers,
clive

Or put the deep freeze on its own unprotected circuit as I have
done.

Interersting post though as my garage, workshop and greenhouse systems
are all on their own rcd's but seperate from the house one.

Best have a CU with double pole RCBOs on it instead of and have Continental
radial system instead of the silly at times ring circuits. If any problem
only the one RCBO trips not the whole house.

Doctor Drivel wrote:

Best have a CU with double pole RCBOs on it instead of and have
Continental radial system instead of the silly at times ring circuits.
If any problem only the one RCBO trips not the whole house.

Separating these risky circuits out such that they are protected by
independent RCDs is generally a good thing to do. RCBOs are one of
several ways of doing this.

The use of a ring or radial circuit does not really have any relevance
though.

--
Cheers,

John.

/================================================== ===============\
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|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Tim Downie wrote:

A friend of mine has a pond with pump & lights wired into a fused spur from
the house ring-main (which is RCD protected). After some recent heavy rain
(which probably managed to penetrate a supposedly "water-tight" outside
junction-box, the RCD tripped, which wouldn't have been a problem if he
hadn't been away on holiday at the time and the fact that the freezer was on
same circuit.

Yup, you don't want to start from there! ;-)

I wondered about changing the existing fused spur for another RCD (like this
one
http://www.screwfix.com/app/sfd/cat/...00509&id=83049)
but I see that it has the same 30mA trip current as the existing one in the
main fusebox

Would I be right in thinking that this wouldn't necessarily stop the main
fusebox RCD tripping?

You would.

Would one with a lower (20mA say) trip current work (and do such things
exist)?

alas no.

Read the sections on discrimination, mitigating the effects of nuisance
trips, and system design using RCDs he

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

to get a feel for the available options.

There is also a fair bit or relevant info in this one:

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



--
Cheers,

John.

/================================================== ===============\
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
...
Doctor Drivel wrote:

Best have a CU with double pole RCBOs on it instead of and have
Continental radial system instead of the silly at times ring circuits.
If any problem only the one RCBO trips not the whole house.

Separating these risky circuits out such that they are protected by
independent RCDs is generally a good thing to do. RCBOs are one of several
ways of doing this.

The use of a ring or radial circuit does not really have any relevance
though.

True an RCBO can be on a ring. Rings are still silly and cheap; one of the
reasons they were adopted..and to have higher currents for electric heaters
post war as the nuclear policy was all electric using unmetered nuclear
power. Although radials may have high currents at the sockets too.

I recall a German looking at a British system; the RCD protecting all of the
house and the fused spurs above the worktops with a fuesd plug hidden behind
the appliance. He thought the system was mad and said it was clearly cheap
at the CU but expensive (and ugly) in fused spurs.

About time we went the same way as the rest of the world. On the Continent
each appliance has an RCBO at the CU. So much easier to isolate. The only
advantage of the UK system is that 3kW kettles are common, whereas in Europe
they only go to around 2kW max. BUt they fill their kettles with hot water
from the combi to make the heat up cheaper and faster.

Doctor Drivel wrote:

Best have a CU with double pole RCBOs on it instead of and have
Continental radial system instead of the silly at times ring
circuits. If any problem only the one RCBO trips not the whole house.

Separating these risky circuits out such that they are protected by
independent RCDs is generally a good thing to do. RCBOs are one of
several ways of doing this.

The use of a ring or radial circuit does not really have any relevance
though.

True an RCBO can be on a ring. Rings are still silly and cheap; one of

Today's ring circuits represent a very good bit of engineering design.

the reasons they were adopted..and to have higher currents for electric

Even if this were true originally, one has to look at how design has
evolved and been refined to where we are today. The ring final circuit
we have now is very well suited to diverse power provision over a wide area.

heaters post war as the nuclear policy was all electric using unmetered
nuclear power. Although radials may have high currents at the sockets too.

I recall a German looking at a British system; the RCD protecting all of
the house and the fused spurs above the worktops with a fuesd plug

No sure what his nationality has to do with it. The system you describe
would not be to standard in the UK wiring regulations, and would rightly
be due criticism. Appliances in kitchens with concealed sockets etc
should have independent switching above the worktop. Use of whole house
RCDs is also long since deprecated.

hidden behind the appliance. He thought the system was mad and said it
was clearly cheap at the CU but expensive (and ugly) in fused spurs.

Rich coming from a German, have you seen their plugs and sockets?

About time we went the same way as the rest of the world. On the
Continent each appliance has an RCBO at the CU. So much easier to
isolate. The only advantage of the UK system is that 3kW kettles are
common, whereas in Europe they only go to around 2kW max. BUt they fill
their kettles with hot water from the combi to make the heat up cheaper
and faster.

Your logic seems as confused as ever.

--
Cheers,

John.

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

"John Rumm" wrote in message
...
Doctor Drivel wrote:

Best have a CU with double pole RCBOs on it instead of and have
Continental radial system instead of the silly at times ring circuits.
If any problem only the one RCBO trips not the whole house.

Separating these risky circuits out such that they are protected by
independent RCDs is generally a good thing to do. RCBOs are one of
several ways of doing this.

The use of a ring or radial circuit does not really have any relevance
though.

True an RCBO can be on a ring. Rings are still silly and cheap; one of

Today's ring circuits represent a very good bit of engineering design.

Engineering? Daisy-chaining sockets together? Are you kidding? I said to
this guy we have two ways back to the meter in earthing. He said if you are
that paranoid run another earth back from the furthest socket on a radial
circuit. He said "use 4 core cable and use the 4th core for the return
earth, that will do it". He was amazed we had an unsheathed eath wire in the
T&E cable. He said "that is cheap".

the reasons they were adopted..and to have higher currents for electric

Even if this were true originally, one has to look at how design has
evolved and been refined to where we are today. The ring final circuit we
have now is very well suited to diverse power provision over a wide area.

You mean a high current circuit on a 32A MCB. Duh!

heaters post war as the nuclear policy was all electric using unmetered
nuclear power. Although radials may have high currents at the sockets
too.

I recall a German looking at a British system; the RCD protecting all of
the house and the fused spurs above the worktops with a fuesd plug

No sure what his nationality has to do with it. The system you describe
would not be to standard in the UK wiring regulations, and would rightly
be due criticism. Appliances in kitchens with concealed sockets etc should
have independent switching above the worktop.

With a socket under the worktop with an inaccessible fuse in the plug, that
might blow. Duh!! The fused spurs looks hideous as well.

Use of whole house RCDs is also long since deprecated.

Long since? Like a few years then.

hidden behind the appliance. He thought the system was mad and said it
was clearly cheap at the CU but expensive (and ugly) in fused spurs.

Rich coming from a German, have you seen their plugs and sockets?

Fused spurs can ruin an nice kitchen worktop.

About time we went the same way as the rest of the world. On the
Continent each appliance has an RCBO at the CU. So much easier to
isolate. The only advantage of the UK system is that 3kW kettles are
common, whereas in Europe they only go to around 2kW max. BUt they fill
their kettles with hot water from the combi to make the heat up cheaper
and faster.

Your logic seems as confused as ever.

Get to know the merits of a system the rest of the world use. Duh!

Doctor Drivel wrote:

True an RCBO can be on a ring. Rings are still silly and cheap; one of

Today's ring circuits represent a very good bit of engineering design.

Engineering? Daisy-chaining sockets together? Are you kidding? I said

Mo, not at all. Do the sums and see how it out performs other circuit
topologies under wide ranging loads and the majority of fault
conditions. This with economy of materials.

Anyone can build cheap and anyone can build strong, but it takes
engineering finesse to do both at once.

to this guy we have two ways back to the meter in earthing. He said if
you are that paranoid run another earth back from the furthest socket on
a radial circuit.

Which is also standard practice in the UK for high integrity radial
circuits.

He said "use 4 core cable and use the 4th core for the
return earth, that will do it".

Does not get you the advantages of dual conductor paths for the phase an
neutral though does it? You would also need 6mm^2 cable in many circuits
to make and equivalent radial. Far less practical from an installers
point of view.

He was amazed we had an unsheathed eath
wire in the T&E cable. He said "that is cheap".

Which is good obviously.

No sure what his nationality has to do with it. The system you
describe would not be to standard in the UK wiring regulations, and
would rightly be due criticism. Appliances in kitchens with concealed
sockets etc should have independent switching above the worktop.

With a socket under the worktop with an inaccessible fuse in the plug,
that might blow. Duh!! The fused spurs looks hideous as well.

You don't need a fused spur on the wall, just a switch. These look
perfectly acceptable:

http://www.tlc-direct.co.uk/Main_Ind..._20/index.html

Use of whole house RCDs is also long since deprecated.

Long since? Like a few years then.

some 20 odd, yes.

hidden behind the appliance. He thought the system was mad and said

Fuses in plugs don't routinely blow unless the appliance develops a
fault. You probably won't be repairing that in situ under the worktop
either, so not really a problem is it.

it was clearly cheap at the CU but expensive (and ugly) in fused spurs.

Rich coming from a German, have you seen their plugs and sockets?

Fused spurs can ruin an nice kitchen worktop.

So don't use them - no need.

About time we went the same way as the rest of the world. On the

What and lower our standards and safety record to match theirs you mean?

Your logic seems as confused as ever.

Get to know the merits of a system the rest of the world use. Duh!

You could start with understanding ours before you go trying to compare
with others.



--
Cheers,

John.

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

"John Rumm" wrote in message
...
Doctor Drivel wrote:

True an RCBO can be on a ring. Rings are still silly and cheap; one of

Today's ring circuits represent a very good bit of engineering design.

Engineering? Daisy-chaining sockets together? Are you kidding? I said

Mo, not at all. Do the sums and see how it out performs other circuit
topologies under wide ranging loads and the majority of fault conditions.
This with economy of materials.

Anyone can build cheap and anyone can build strong, but it takes
engineering finesse to do both at once.

to this guy we have two ways back to the meter in earthing. He said if
you are that paranoid run another earth back from the furthest socket on
a radial circuit.

Which is also standard practice in the UK for high integrity radial
circuits.

He said "use 4 core cable and use the 4th core for the return earth, that
will do it".

Does not get you the advantages of dual conductor paths for the phase an
neutral though does it? You would also need 6mm^2 cable in many circuits
to make and equivalent radial.

They do not have countless sockets on one radial. In France it is 8 maximum
on a 16A MCB.

Far less practical from an installers point of view.

You mean cheap, having all the downsrairs sockets on one 32A MCB. They would
have that split into many 16 MCBs. Better. Divider and rule.

He was amazed we had an unsheathed eath wire in the T&E cable. He said
"that is cheap".

Which is good obviously.

No sure what his nationality has to do with it. The system you describe
would not be to standard in the UK wiring regulations, and would rightly
be due criticism. Appliances in kitchens with concealed sockets etc
should have independent switching above the worktop.

With a socket under the worktop with an inaccessible fuse in the plug,
that might blow. Duh!! The fused spurs looks hideous as well.

You don't need a fused spur on the wall, just a switch. These look
perfectly acceptable:

http://www.tlc-direct.co.uk/Main_Ind..._20/index.html

Use of whole house RCDs is also long since deprecated.

Long since? Like a few years then.

some 20 odd, yes.

More a few years. I have seen many new builds with RCDs on the whole CU.

hidden behind the appliance. He thought the system was mad and said

Fuses in plugs don't routinely blow unless the appliance develops a fault.
You probably won't be repairing that in situ under the worktop either, so
not really a problem is it.

They CAN blow and when they do an appliance has to be dragged out.

it was clearly cheap at the CU but expensive (and ugly) in fused spurs.

Rich coming from a German, have you seen their plugs and sockets?

Fused spurs can ruin an nice kitchen worktop.

So don't use them - no need.

About time we went the same way as the rest of the world. On the

What and lower our standards and safety record to match theirs you mean?

Theirs superior.

Your logic seems as confused as ever.

Get to know the merits of a system the rest of the world use. Duh!

You could start with understanding ours before you go trying to compare
with others.

I understand ours and it is cheap and nasty. In France to isolate a
dishwasher you go to the CU and throw the RCBO. Any problems and they
throws.

"John Rumm" wrote in message
...

With a socket under the worktop with an inaccessible fuse in the plug,
that might blow. Duh!! The fused spurs looks hideous as well.

You don't need a fused spur on the wall, just a switch. These look
perfectly acceptable:

http://www.tlc-direct.co.uk/Main_Ind..._20/index.html

They have one MCB or RCBO at the CU to isolate the appliance. Nice and neat,
out of the way and accessible. The best way.

"John Rumm" wrote in message
...
Doctor Drivel wrote:

True an RCBO can be on a ring. Rings are still silly and cheap; one of

Today's ring circuits represent a very good bit of engineering design.

Engineering? Daisy-chaining sockets together? Are you kidding? I said

Mo, not at all. Do the sums and see how it out performs other circuit
topologies under wide ranging loads and the majority of fault conditions.
This with economy of materials.

As one German said to me when I said rings are legal in Germany. "why run a
ring off one MCB when this can be run in two runs (radials) and have two
MCBs protecting each. To him it just did not add up. He was right.

On Wed, 22 Aug 2007 17:57:57 +0100, "Doctor Drivel"
wrote:

As one German said to me when I said rings are legal in Germany. "why run a
ring off one MCB when this can be run in two runs (radials) and have two
MCBs protecting each. To him it just did not add up.

Would this explain why, proportionately to population, the number of
people killed by electrical accidents in Germany is 3 times greater
than the UK and in France is about 10 times greater?


--
Peter Parry.
http://www.wpp.ltd.uk/

"Peter Parry" wrote in message
...
On Wed, 22 Aug 2007 17:57:57 +0100, "Doctor Drivel"
wrote:

As one German said to me when I said rings are legal in Germany. "why run
a
ring off one MCB when this can be run in two runs (radials) and have two
MCBs protecting each. To him it just did not add up.

Would this explain why, proportionately to population, the number of
people killed by electrical accidents in Germany is 3 times greater
than the UK and in France is about 10 times greater?

No it would not. There is no reason for those figures to relate to the
types of electrical systems. It is more a culture towards safety than the
systems.

Doctor Drivel wrote:

They do not have countless sockets on one radial. In France it is 8
maximum on a 16A MCB.

Which exemplifies why low capacity radials are not well suited to
general power provision in a home.

Far less practical from an installers point of view.

You mean cheap, having all the downsrairs sockets on one 32A MCB. They
would have that split into many 16 MCBs. Better. Divider and rule.

One ring circuit for the kitchen, another for the other downstairs
sockets, plus a non RCD protected radial for any circuits with low trip
tolerance would seem more than adequate in most domestic situations.

Use of whole house RCDs is also long since deprecated.

Long since? Like a few years then.

some 20 odd, yes.

More a few years. I have seen many new builds with RCDs on the whole CU.

Whole house RCDs were briefly allowed in the 15th edition IIUC. So since
that covered the '80s basically, the scope when that was acceptable was
limited. It fairly soon became apparent that it was not a good solution.

hidden behind the appliance. He thought the system was mad and said

Fuses in plugs don't routinely blow unless the appliance develops a
fault. You probably won't be repairing that in situ under the worktop
either, so not really a problem is it.

They CAN blow and when they do an appliance has to be dragged out.

They can, but rarely if ever do in the absence of a fault. I don't
recall the last time I need to replace a fuse for a non faulty appliance.

What and lower our standards and safety record to match theirs you mean?

Theirs superior.

Figures?

I understand ours and it is cheap and nasty. In France to isolate a
dishwasher you go to the CU and throw the RCBO. Any problems and they
throws.

Here you would throw the switch above the counter marked "Dishwasher",
seems somewhat better to me.

--
Cheers,

John.

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

Doctor Drivel wrote:

They have one MCB or RCBO at the CU to isolate the appliance. Nice and
neat, out of the way and accessible. The best way.

Requiring dedicated circuit wiring for each and every appliance.... hmmm
novel.

--
Cheers,

John.

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

Doctor Drivel wrote:

As one German said to me when I said rings are legal in Germany. "why
run a ring off one MCB when this can be run in two runs (radials) and
have two MCBs protecting each. To him it just did not add up. He was

as clueless as you.

--
Cheers,

John.

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

On Aug 22, 9:44 pm, Peter Parry wrote:
On Wed, 22 Aug 2007 17:57:57 +0100, "Doctor Drivel"

wrote:
As one German said to me when I said rings are legal in Germany. "why run a
ring off one MCB when this can be run in two runs (radials) and have two
MCBs protecting each. To him it just did not add up.

Would this explain why, proportionately to population, the number of
people killed by electrical accidents in Germany is 3 times greater
than the UK and in France is about 10 times greater?

AIUI in Holland proportionately to population, the number of people
killed by electrical accidents is /half/ that of the UK, and I don't
think they have ring mains... do they?

cheers,
Pete.

On 2007-08-23 00:02:42 +0100, Pete C said:

On Aug 22, 9:44 pm, Peter Parry wrote:
On Wed, 22 Aug 2007 17:57:57 +0100, "Doctor Drivel"

wrote:
As one German said to me when I said rings are legal in Germany. "why run a
ring off one MCB when this can be run in two runs (radials) and have two
MCBs protecting each. To him it just did not add up.

Would this explain why, proportionately to population, the number of
people killed by electrical accidents in Germany is 3 times greater
than the UK and in France is about 10 times greater?

AIUI in Holland proportionately to population, the number of people
killed by electrical accidents is /half/ that of the UK, and I don't
think they have ring mains... do they?

cheers,
Pete.

Final circuits in Holland are radial.

The numbers are low in all cases, so it would be necessary to look at
individual accidents to see whether the cause was related to circuit
protection or other causes

"John Rumm" wrote in message
...
Doctor Drivel wrote:

They do not have countless sockets on one radial. In France it is 8
maximum on a 16A MCB.

Which exemplifies why low capacity radials are not well suited to general
power provision in a home.

???????

Far less practical from an installers point of view.

You mean cheap, having all the downsrairs sockets on one 32A MCB. They
would have that split into many 16 MCBs. Better. Divide and rule.

One ring circuit for the kitchen, another for the other downstairs
sockets, plus a non RCD protected radial for any circuits with low trip
tolerance would seem more than adequate in most domestic situations.

They split it up well.

Use of whole house RCDs is also long since deprecated.

Long since? Like a few years then.

some 20 odd, yes.

More a few years. I have seen many new builds with RCDs on the whole CU.

Whole house RCDs were briefly allowed in the 15th edition IIUC. So since
that covered the '80s basically, the scope when that was acceptable was
limited. It fairly soon became apparent that it was not a good solution.

I have seen them on new builds of only 5 years ago and less.

hidden behind the appliance. He thought the system was mad and said

Fuses in plugs don't routinely blow unless the appliance develops a
fault. You probably won't be repairing that in situ under the worktop
either, so not really a problem is it.

They CAN blow and when they do an appliance has to be dragged out.

They can, but rarely if ever do in the absence of a fault. I don't recall
the last time I need to replace a fuse for a non faulty appliance.

But can do and behind an appliance.

What and lower our standards and safety record to match theirs you mean?

Theirs superior.

Figures?

I understand ours and it is cheap and nasty. In France to isolate a
dishwasher you go to the CU and throw the RCBO. Any problems and they
throws.

Here you would throw the switch above the counter marked "Dishwasher",
seems somewhat better to me.

Which looks crap and is not an RCBO.

"John Rumm" wrote in message
...
Doctor Drivel wrote:

They have one MCB or RCBO at the CU to isolate the appliance. Nice and
neat, out of the way and accessible. The best way.

Requiring dedicated circuit wiring for each and every appliance.... hmmm
novel.

No. The standard in the rest of the world and safer. Ours is cheap - and
nasty.

"John Rumm" wrote in message
...
Doctor Drivel wrote:

As one German said to me when I said rings are legal in Germany. "why run
a ring off one MCB when this can be run in two runs (radials) and have
two MCBs protecting each. To him it just did not add up. He was

as clueless as you.

It seems the UK is out of step with the rest of them (but thinks it is in
step)...as is your brain.

On 2007-08-23 08:31:26 +0100, "Doctor Drivel" said:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

They have one MCB or RCBO at the CU to isolate the appliance. Nice and
neat, out of the way and accessible. The best way.

Requiring dedicated circuit wiring for each and every appliance.... hmmm novel.

No. The standard in the rest of the world and safer. Ours is cheap -
and nasty.

Have you seen French electrical fittings and wiring practices?
They are better than the U.S., but that is all that can be said.


The UK system can't be described as cheap or nasty in the sense of the
fittings used or the electrical design. In other countries, the
radial design does result in the need for many more circuit breakers in
an installation, which increases the cost on that side somewhat.

On Wed, 22 Aug 2007 16:02:42 -0700, Pete C
wrote:

AIUI in Holland proportionately to population, the number of people
killed by electrical accidents is /half/ that of the UK, and I don't
think they have ring mains... do they?

The numbers killed in electrical accidents isn't recorded very
consistently between countries. For example some record only
electrocution deaths, some would record deaths in a fire caused by
electrical faults as "caused by electricity" others as a fire death.
There are certain countries in the EU with dire standards - France,
Spain, Portugal, Italy, Greece and most of the old East Europeans
states amongst them. In these countries deaths primarily caused by
electrocution are fairly common.

From a hazard point of view fixed wiring (even French) doesn't cause
many accidents directly. The direct difference between ring and
radial is also minimal. However, the consequential hazards are not.
A characteristic of many continental installations is that there are
a smaller number of sockets in a house than for a house of similar
age in the UK and consequently much more use of trailing extensions.
These are inherently more hazardous than wall sockets and contribute
to far more fires of electric origin than does fixed wiring. The
lack of any form of appliance lead protection coupled with high trip
currents also makes fires caused by equipment failure more common on
the continent than in the UK.

All countries using the CEE 7/4 (Shuko) plugs tend to have a number
of child fatalities each year caused by objects being poked into the
unprotected openings. The UK has virtually no such accidents with
the shielded 13A socket.

The Schutzkontakt (Shuko) plug socket pair is designed to be safe in
that the side earth contact must mate before the pins and the
recessed socket prevents fingers touching the pins as they are being
inserted. Unfortunately there are a number of other systems using the
same or similar pin sizing and spacing as Shuko but without the earth
connection or recessed socket. As a result there are accidents
caused by plugging Shuko plugs into sockets where the earth is either
absent or ineffective as it doesn't touch the side contacts. A
further catch is that in such situations the side contacts on the
plug become live so giving a shock to anyone who tries to remove it
in such fault conditions. This commonly occurs with the two pin CEE
7/16 (Europlug 2.5 A/250 V) unearthed socket which isn't supposed to
fit a Shuko plug but many will. The French 2 pin plug with female
earth will also usually fit a Shuko socket - but without the earth
making. The CEE 7/7 is a cross between the Shuko and French systems
with side contacts and a female earth receptacle and usually supplied
with new equipment.

Although rated at 16A it is also possible to buy Shuko plugs with
considerably lower current carrying capacity and many "Shuko" plugs
are of poor quality and prone to overheating when running at high
loads. I have seen some dire examples around of very poorly made
Shuko plugs and nothing like the same poor quality in even the
cheapest BS 1363 plugs (probably because BS1363 plugs require third
party certification whilst manufacturers can self certify Shuko).

Another issue with the continental two pin plugs is that the wiring
of the live and neutral is random (and even if it were not the plugs
can be inserted any way around). Usually this isn't an issue but it
becomes one when freestanding lamps using Edison Screw (the
continental standard) fittings. The threaded part of the shell can
be left live and shocks while changing bulbs and accidentally
touching the bulb thread are common. The shock isn't usually fatal,
the fall off the ladder more often is!

There is no question that BS 1363 is a fundamentally much safer
system than the Shuko and its variants. This is hardly unexpected as
the Shuko design dates from the 1920's.

The improved safety of the ring over the radial stems largely from
secondary effects of the greater number of fixed sockets and fuse
protection of the appliance lead. Together these reduce the number
of fires caused by overloaded and damaged extensions. There is of
course nothing to stop you wiring a BS1363 layout in radial form -
but there would be no advantage in doing so.
--
Peter Parry.
http://www.wpp.ltd.uk/

Doctor Drivel wrote:

"John Rumm" wrote in message
...
Doctor Drivel wrote:

They do not have countless sockets on one radial. In France it is 8
maximum on a 16A MCB.

Which exemplifies why low capacity radials are not well suited to
general power provision in a home.

???????

Because you end up needing at least half a dozen circuits per floor just
for sockets, with all the cost and wiring complexity that entails. You
are also stuck with no more practical load than one high current device
per circuit - a right PITA in a kitchen for example.

Whole house RCDs were briefly allowed in the 15th edition IIUC. So
since that covered the '80s basically, the scope when that was
acceptable was limited. It fairly soon became apparent that it was not
a good solution.

I have seen them on new builds of only 5 years ago and less.

Are you:
1) Sure you know what you were looking at
2) Sure it was not a TT install
3) Not just making up this stuff like normal

They can, but rarely if ever do in the absence of a fault. I don't
recall the last time I need to replace a fuse for a non faulty appliance.

But can do and behind an appliance.

can in theory. I have never had it happen. In fact I have not had a fuse
blow in anything in the last 15 years that I can recall.

What and lower our standards and safety record to match theirs you
mean?

Theirs superior.

Figures?

Still waiting...

Here you would throw the switch above the counter marked "Dishwasher",
seems somewhat better to me.

Which looks crap and is not an RCBO.

You are aware that there is no particular advantage to having RCD
protection on fixed appliances such as dishwashers? (TT excepted)


--
Cheers,

John.

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

Doctor Drivel wrote:

"John Rumm" wrote in message
...
Doctor Drivel wrote:

They have one MCB or RCBO at the CU to isolate the appliance. Nice
and neat, out of the way and accessible. The best way.

Requiring dedicated circuit wiring for each and every appliance....
hmmm novel.

No. The standard in the rest of the world and safer. Ours is cheap -
and nasty.

Figures?

Ours is certainly not cheap, and IME the quality of accessories is
usually noticeably higher.

The accident statistics do not support your claims either.

--
Cheers,

John.

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

Andy Hall wrote:

AIUI in Holland proportionately to population, the number of people
killed by electrical accidents is /half/ that of the UK, and I don't
think they have ring mains... do they?

cheers,
Pete.

Final circuits in Holland are radial.

The numbers are low in all cases, so it would be necessary to look at
individual accidents to see whether the cause was related to circuit
protection or other causes

Much also depends on if they record accidents with electrical appliances
separately from those for fixed wiring, and how they record things like
fires started by electrical faults. Without detailed analysis of the
stats recording process they as usual tell you a small part of the story.

--
Cheers,

John.

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

On Thu, 23 Aug 2007 14:34:21 +0100 someone who may be John Rumm
wrote this:-

Figures?

Still waiting...

I'm waiting for these too, despite the various claims in other parts
of the thread.

Which looks crap and is not an RCBO.

You are aware that there is no particular advantage to having RCD
protection on fixed appliances such as dishwashers? (TT excepted)

Keep up the good work by pointing out the flaws in Mr Dribble's
assertions.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Thu, 23 Aug 2007 14:16:13 +0100 someone who may be Peter Parry
wrote this:-

There is no question that BS 1363 is a fundamentally much safer
system than the Shuko and its variants. This is hardly unexpected as
the Shuko design dates from the 1920's.

This is something I entirely agree with you on. Wiring is something
that the UK has got right for a long time, unlike say plumbing which
was decidedly dodgy until say the 1960s and the adoption of single
pipe drainage almost universally.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"Andy Hall" wrote in message
...
On 2007-08-23 08:31:26 +0100, "Doctor Drivel" said:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

They have one MCB or RCBO at the CU to isolate the appliance. Nice and
neat, out of the way and accessible. The best way.

Requiring dedicated circuit wiring for each and every appliance.... hmmm
novel.

No. The standard in the rest of the world and safer. Ours is cheap - and
nasty.

Have you seen French electrical fittings and wiring practices? They
are better than the U.S., but that is all that can be said.

Have you seen the electrics in a remote village in Slovakia? They are
definately cheap and nasty. The old high rise flats in the citys are not
much better.
I wonder what the authorities here would say if a British villager decided
to make their own electrical connection to an overhead supply.

Adam

In article ,
David Hansen writes:
On Thu, 23 Aug 2007 14:16:13 +0100 someone who may be Peter Parry
wrote this:-

There is no question that BS 1363 is a fundamentally much safer
system than the Shuko and its variants. This is hardly unexpected as
the Shuko design dates from the 1920's.

This is something I entirely agree with you on. Wiring is something
that the UK has got right for a long time, unlike say plumbing which
was decidedly dodgy until say the 1960s and the adoption of single
pipe drainage almost universally.

BS1363 family is the most recently designed domestic plug and
socket system in the world. It was the result of some 10 years
of competition between manufacturers to design a new standard.
It has been adopted in whole or part by more countries in the
world than any other domestic plug and socket standard. The
standard has been further improved a number of times over its
60 year history, and the mandatory testing required is very
rigorous.

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

David Hansen wrote:

Keep up the good work by pointing out the flaws in Mr Dribble's
assertions.

Not much of a challenge is it! Still he seems to have sloped off tail
between legs again for now.

--
Cheers,

John.

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

"John Rumm" wrote in message
...
Doctor Drivel wrote:

"John Rumm" wrote in message
...
Doctor Drivel wrote:

They do not have countless sockets on one radial. In France it is 8
maximum on a 16A MCB.

Which exemplifies why low capacity radials are not well suited to
general power provision in a home.

???????

Because you end up needing at least half a dozen circuits per floor just
for sockets,

So that is 8 x 6 which 48 sockets. A lot of sockets per floor.

with all the cost and wiring complexity that entails.

Ah cost!! Yes rings are cheap....and nasty.

You are also stuck with no more practical load than one high current
device per circuit - a right PITA in a kitchen for example.

In a kitchen individual circuit for high load appliances is a great
advantage in many ways.

Whole house RCDs were briefly allowed in the 15th edition IIUC. So since
that covered the '80s basically, the scope when that was acceptable was
limited. It fairly soon became apparent that it was not a good solution.

I have seen them on new builds of only 5 years ago and less.

Are you:
1) Sure you know what you were looking at

Yes. A CU.

2) Sure it was not a TT install
3) Not just making up this stuff like normal

I know what I see, You make things up as you are from Essex.

They can, but rarely if ever do in the absence of a fault. I don't
recall the last time I need to replace a fuse for a non faulty
appliance.

But can do and behind an appliance.

can in theory. I have never had it happen.

I have.

In fact I have not had a fuse blow in anything in the last 15 years that I
can recall.

Lucky man. How about the RCSs tripping the whole house when a 230V
downlighter blows. Great eh!!!

What and lower our standards and safety record to match theirs you
mean?

Theirs superior.

Figures?

Still waiting...

Look at the systems. Theirs is superior. Not a cheap ring effort to reduce
MCBs. and have a small CU.

Here you would throw the switch above the counter marked "Dishwasher",
seems somewhat better to me.

Which looks crap and is not an RCBO.

You are aware that there is no particular advantage to having RCD
protection on fixed appliances such as dishwashers? (TT excepted)

There IS!!!!!!!!