I've just moved into a new flat and in the lounge, next to every
standard plug socket, there are sockets with three round holes in a
triangle (like a standard plug socket but with roung holes rather than
rectangular). Can anyone tell me what they are? There is also a
dimmer switch that is not connected to anything, so could they be for
lighting? I have tried european plugs but they do not fit. Any ideas
would be much appreciated...

I've just moved into a new flat and in the lounge, next to every
standard plug socket, there are sockets with three round holes in a
triangle (like a standard plug socket but with roung holes rather than
rectangular). Can anyone tell me what they are?

It is normal to use BS576 round pin sockets for lighting, in order to
prevent the sockets' accidental use for portable equipment. I would suspect
that the dimmer switch does, indeed, control the socket in question. In my
new loft room, I have installed 5 of these on 3 indepedent switches (not
dimmers as I only use CFL bulbs). This is because ceiling lighting doesn't
work well in a bedroom, as it is harsh and prevents comfortable reading.
Having table and standard lamps dotted around is much more cosy.

http://www.tlc-direct.co.uk/Main_Ind...s_2/index.html

It will normally be a 2A or 5A fitting. Measure the live-neutral distance to
determine which.

Christian.

Plug a table lamp into them.

foxlj wrote:
I've just moved into a new flat and in the lounge, next to every
standard plug socket, there are sockets with three round holes in a
triangle (like a standard plug socket but with roung holes rather than
rectangular). Can anyone tell me what they are? There is also a
dimmer switch that is not connected to anything, so could they be for
lighting? I have tried european plugs but they do not fit. Any ideas
would be much appreciated...


Normally a separate LIGHTING circuit, possibly dimmed, that takes UK
style 5 Amp rated non fused plugs.

I have just such here in many rooms.

Its designed to be able to switch off ALL the standard/table/reading
lamps from one place etc.

I cannot just test it because a standard plug does not fit into them.
Will try the round pin plugs as suggested above! Thanks very much!

It is normal to use BS576 round pin sockets for lighting

I meant BS546, not 576, in case you want to do some searching.

Christian.

I cannot just test it because a standard plug does not fit into them.
Will try the round pin plugs as suggested above! Thanks very much!

Christian McArdle wrote:
It is normal to use BS576 round pin sockets for lighting

I meant BS546, not 576, in case you want to do some searching.

Christian.


Thanks very much Christian - will definately give it a go!

On 24 Aug 2006 04:55:25 -0700, "foxlj" wrote:

I cannot just test it because a standard plug does not fit into them.
Will try the round pin plugs as suggested above! Thanks very much!

B&Q stock those plugs.

--
Frank Erskine

foxlj wrote:
I cannot just test it because a standard plug does not fit into them.
Will try the round pin plugs as suggested above! Thanks very much!

http://www.screwfix.com/app/sfd/cat/...84227&id=13322

Is what you want. Almost all decent electrical shops will carry them.

"Christian McArdle" wrote in
message ...
I've just moved into a new flat and in the lounge, next to every
standard plug socket, there are sockets with three round holes in
a
triangle (like a standard plug socket but with roung holes rather
than
rectangular). Can anyone tell me what they are?

It is normal to use BS576 round pin sockets for lighting, in order
to
prevent the sockets' accidental use for portable equipment. I would
suspect
that the dimmer switch does, indeed, control the socket in question.
In my
new loft room, I have installed 5 of these on 3 indepedent switches
(not
dimmers as I only use CFL bulbs). This is because ceiling lighting
doesn't
work well in a bedroom, as it is harsh and prevents comfortable
reading.
Having table and standard lamps dotted around is much more cosy.


http://www.tlc-direct.co.uk/Main_Ind...s_2/index.html

It will normally be a 2A or 5A fitting. Measure the live-neutral
distance to
determine which.

Christian.




Oh dear you are making me feel OLD !!! Time was when we only had the
round pin sockets in 2, 5, and 15 amp the later being wired radially
in good old 7/029. Then they brought in these modern square ones !

AWEM

In article om,
foxlj wrote:
I've just moved into a new flat and in the lounge, next to every
standard plug socket, there are sockets with three round holes in a
triangle (like a standard plug socket but with roung holes rather than
rectangular). Can anyone tell me what they are?

Almost certainly one of these - it gives the distance between pins so
measure your sockets to match up.

http://www.tlc-direct.co.uk/Main_Ind...s_2/index.html

There is also a dimmer switch that is not connected to anything, so
could they be for lighting? I have tried european plugs but they do not
fit. Any ideas would be much appreciated...

Commonly used for lighting circuits at floor level - things like table
lamps which you wish to switch or dim from a central point. Avoids
plugging the Hoover in and blowing up the dimmer. ;-)

--
*Growing old is inevitable, growing up is optional

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

"Andrew Mawson" wrote in
message ...

snip

Oh dear you are making me feel OLD !!! Time was when we only had
the
round pin sockets in 2, 5, and 15 amp the later being wired
radially
in good old 7/029. Then they brought in these modern square ones !


What was scary were the adapter that could be used to allow a 2 or 5
amp plugs (and hence appliance) into a 15 amp socket, without any
down rating of the protection device - there is still a lot to said
for radial circuits (with the protection at the panel) but not when
they can be so easily abused...

"Jerry" wrote in message
reenews.net...

snip

What was scary were the adapter that could be used to allow a 2 or
5
amp plugs (and hence appliance) into a 15 amp socket, without any
down rating of the protection device - there is still a lot to said
for radial circuits (with the protection at the panel) but not when
they can be so easily abused...


Although they are still safer than an abused BS1363 plug which is
then being feed by a ring circuit rated at 30 amps...

On Thu, 24 Aug 2006 17:33:39 +0100 someone who may be "Jerry"
wrote this:-

there is still a lot to said
for radial circuits (with the protection at the panel)

Is there, for providing general power around buildings?


--
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, 24 Aug 2006 21:22:57 +0100 someone who may be "Jerry"
wrote this:-

Although they are still safer than an abused BS1363 plug which is
then being feed by a ring circuit rated at 30 amps...

Only if the fuse has been replaced by something else.

Of course someone who does this may well also do the same sort of
thing at the consumer unit.


--
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 in message
news
On Thu, 24 Aug 2006 17:33:39 +0100 someone who may be "Jerry"
wrote this:-

there is still a lot to said
for radial circuits (with the protection at the panel)

Is there, for providing general power around buildings?


Yes, other than cost.

"David Hansen" wrote in message
...
On Thu, 24 Aug 2006 21:22:57 +0100 someone who may be "Jerry"
wrote this:-

Although they are still safer than an abused BS1363 plug which is
then being feed by a ring circuit rated at 30 amps...

Only if the fuse has been replaced by something else.

Of course someone who does this may well also do the same sort of
thing at the consumer unit.


But in most cases it's a tad more difficult than just inserting an
old nail or bolt shank....

Many ignorant [1] people will attempt to 'mend' a BS1363 plug were
they would not dare to tamper with a distribution panel.

[1] use in the true meaning of the word.

On Sat, 26 Aug 2006 10:23:12 +0100 someone who may be "Jerry"
wrote this:-

there is still a lot to said
for radial circuits (with the protection at the panel)

Is there, for providing general power around buildings?

Yes, other than cost.

I note that you didn't specify any advantages.

There are 17 single sockets, 17 twin sockets and 3 connection units
in my house, on two ring final circuits. Were they to be wired
radially, in say up to six singles or three twins per circuit and
two of the three connection units on separate radials that comes to
11 radial circuits. That wouldn't just be expensive, it would be
difficult to find somewhere to put all the cables in places. The
ring arrangement is also far more flexible, allowing changes to be
made much more easily.

Other than a few specific circumstances ISTM that radial wiring has
no advantages for general circuits.


--
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 in message
...
On Sat, 26 Aug 2006 10:23:12 +0100 someone who may be "Jerry"
wrote this:-

there is still a lot to said
for radial circuits (with the protection at the panel)

Is there, for providing general power around buildings?

Yes, other than cost.

I note that you didn't specify any advantages.

Fridges and Freezers, computers and telecom / data handling, any RCD
protected circuit, to name a few applications that benefit from
dedicated supplies. Then there is the abuse factor, that started this
discussion, a distr' panel fitted with CB's protecting individual
outlets is going to a dammed sight more difficult to abuse that
bunging a nail or bolt shank (let alone just the wrong fuse) into a
BS1363 plug.


There are 17 single sockets, 17 twin sockets and 3 connection units
in my house, on two ring final circuits. Were they to be wired
radially, in say up to six singles or three twins per circuit and
two of the three connection units on separate radials that comes to
11 radial circuits. That wouldn't just be expensive, it would be
difficult to find somewhere to put all the cables in places. The
ring arrangement is also far more flexible, allowing changes to be
made much more easily.

Yes, and one fault can take out the whole bleeding lot, yes the panel
would be bigger, but it's not bigger that what we have been used to -
assuming that one large panel was used and not smaller panels (on
different floors, for example) supplied via sub mains.


Other than a few specific circumstances ISTM that radial wiring has
no advantages for general circuits.


Only to a closed mind used to the cheapness and ease of ring circuit
installation.

On Sun, 27 Aug 2006 10:35:04 +0100 someone who may be "Jerry"
wrote this:-

Fridges and Freezers, computers and telecom / data handling, any RCD
protected circuit, to name a few applications that benefit from
dedicated supplies.

Fridges and freezers don't really "benefit" from dedicated supplies,
in most circumstances. The one circumstance where there might be
benefit is where an over-enthusiastic RCD disconnects the circuit
they are on. However, I keep an eye on several houses with fridges
and freezers on RCD protected circuits and this has yet to be a
problem in any of them. The sort of telecom/data handling equipment
one has in houses doesn't particularly benefit either, if it did
then people would be advocating dedicated supplies for televisions
and the like. I have no idea what you mean by "any RCD protected
circuit".

Then there is the abuse factor, that started this
discussion, a distr' panel fitted with CB's protecting individual
outlets is going to a dammed sight more difficult to abuse that
bunging a nail or bolt shank (let alone just the wrong fuse) into a
BS1363 plug.

So, is you objection actually an objection to individual fuses for
equipment, rather then the final circuit wiring?

Yes, and one fault can take out the whole bleeding lot,

Provided the system is designed, installed and maintained properly
such a fault will be very rare. ISTM that there is no reason to
design electrical systems on the assumption that the design,
installation or maintenance will be poor, especially when the UK
approach has been shown to be safer.

yes the panel
would be bigger, but it's not bigger that what we have been used to -

Who is this "we" and what size of panel have they been used to?

Other than a few specific circumstances ISTM that radial wiring has
no advantages for general circuits.

Only to a closed mind

Excellent, personal abuse. I disagree with you and so you accuse me
of having a closed mind.

used to the cheapness and ease of ring circuit
installation.

Ah, so you do now accept that there is at least one more advantage
to ring wiring other than just cost.


--
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 in message
...
On Sun, 27 Aug 2006 10:35:04 +0100 someone who may be "Jerry"
wrote this:-

Fridges and Freezers, computers and telecom / data handling, any
RCD
protected circuit, to name a few applications that benefit from
dedicated supplies.

Fridges and freezers don't really "benefit" from dedicated
supplies,
in most circumstances. The one circumstance where there might be
benefit is where an over-enthusiastic RCD disconnects the circuit
they are on.

So you admit now that ring circuits can (and do) casue problems by
the nature of their disgn?

However, I keep an eye on several houses with fridges
and freezers on RCD protected circuits and this has yet to be a
problem in any of them. The sort of telecom/data handling equipment
one has in houses doesn't particularly benefit either, if it did
then people would be advocating dedicated supplies for televisions

The point I'm making is that one fault tripping the distr' panel
protection can and will take out every appliance on a ring circuit
[1], with radial that can't happen. Also one has to think about
maintenance etc., with the ring circuit isolated many houses now only
have on useable socket, that on the cooker supply (if of fitted).

[1] one then has to find out what appliance, accessory or section of
wiring has caused the fault before any appliance can be re-supplied.

and the like. I have no idea what you mean by "any RCD protected
circuit".

There are some outlets that benefit from additional protection (RCD,
Surge protection etc.), with radial circuits that protection can be
placed within the distr' panel, rather than an unsightly socket or
(worse) a plug-in device that's use might get forgotten or ignored.


Then there is the abuse factor, that started this
discussion, a distr' panel fitted with CB's protecting individual
outlets is going to a dammed sight more difficult to abuse that
bunging a nail or bolt shank (let alone just the wrong fuse) into
a
BS1363 plug.

So, is you objection actually an objection to individual fuses for
equipment, rather then the final circuit wiring?

So you think that a 2 amp appliance protected with a 30 amp device is
safer than if that protection was 15 amps or less when some halfwit
overrides the plugs internal protection device?


Yes, and one fault can take out the whole bleeding lot,

Provided the system is designed, installed and maintained properly
such a fault will be very rare. ISTM that there is no reason to
design electrical systems on the assumption that the design,
installation or maintenance will be poor, especially when the UK
approach has been shown to be safer.

yes the panel
would be bigger, but it's not bigger that what we have been used
to -

Who is this "we" and what size of panel have they been used to?

Perhaps you can't or are not old enough to remember when houses were
wired with radial circuits?


Other than a few specific circumstances ISTM that radial wiring
has
no advantages for general circuits.

Only to a closed mind

Excellent, personal abuse. I disagree with you and so you accuse me
of having a closed mind.

If you want to take the remark as personal abuse so be, it was not
intended to be, I was just pointing out that some will defend what
they have been told without question - that is not a fault of the
individual but of the (wider) 'education system'. People are not (and
have not for many years) being taught to question any more, but to
just accept what we are told.


used to the cheapness and ease of ring circuit
installation.

Ah, so you do now accept that there is at least one more advantage
to ring wiring other than just cost.


Cheapness is not always an advantage...

In article ,
David Hansen writes:
On Sun, 27 Aug 2006 10:35:04 +0100 someone who may be "Jerry"
wrote this:-

Fridges and Freezers, computers and telecom / data handling, any RCD
protected circuit, to name a few applications that benefit from
dedicated supplies.

Fridges and freezers don't really "benefit" from dedicated supplies,
in most circumstances. The one circumstance where there might be
benefit is where an over-enthusiastic RCD disconnects the circuit
they are on.

When I do a rewire, I put in an non-RCD protected circuit. This
gets things like fridge, freezer, washing machine, oven (if 13A
plug type), central heating, burglar alarm (if not on lighting
circuit), any life support systems such as fish tank filters and
heaters (with a dedicated RCD), etc, i.e. all the things you
don't want to trip off because of some appliance's earth leak,
and which don't represent any significant safety risk due to
their own earth leakage (except fish tank, hence dedicated RCD).

--
Andrew Gabriel

Jerry wrote:

So you admit now that ring circuits can (and do) casue problems by
the nature of their disgn?

Radial circuits can cause problems by the nature of their design too.
In both cases the designer would have to have failed to consider the use
to which the circuit is to be put.

The point I'm making is that one fault tripping the distr' panel
protection can and will take out every appliance on a ring circuit
[1], with radial that can't happen.

Uh? - a trip on a radial circuit will also take out every appliance on
that circuit.

Also one has to think about maintenance etc., with the ring circuit
isolated many houses now only have on useable socket, that on the
cooker supply (if of fitted).

Most houses tend to have two rings, typically for ground floor and first
floor, and a third ring for the kitchen is now becoming common practice.
Only very small properties or ones wired a very long time ago will be
found with one ring circuit.

[1] one then has to find out what appliance, accessory or section of
wiring has caused the fault before any appliance can be re-supplied.

The same is true with any circuit. Your points really are all about the
number of outlets / appliances / floor area served by the circuits,
rather than the actual circuit topology.

There are some outlets that benefit from additional protection (RCD,
Surge protection etc.), with radial circuits that protection can be
placed within the distr' panel, rather than an unsightly socket or
(worse) a plug-in device that's use might get forgotten or ignored.

The same is true with ring circuits, indeed normal practice is now for
all house ring circuits to be RCD protected at the distribution board.

So you think that a 2 amp appliance protected with a 30 amp device is
safer than if that protection was 15 amps or less when some halfwit
overrides the plugs internal protection device?

This is an irrelevant point since a 13 A plug fuse perfectly well
protects a 0.5 mm^2 flex (for normal flex lengths), this being the
smallest flex in common use. The halfwit would need to fit a solid
quarter-inch bar in place of the fuse to cause any real danger!

Perhaps you can't or are not old enough to remember when houses were
wired with radial circuits?

I am, and your point is ...?

Radial socket circuits are still permitted of course and are often used,
although I've often noticed that electricians will unthinkingly install
32 A ring where a 20 A radial might have been more sensible.

Nevertheless the ring concept is economical and convenient and has
certainly stood the test of time.

Another advantage of the ring is the relative ease of implementing the
Section 607 high-integrity earthing requirements, where needed.

--
Andy

"Andrew Gabriel" wrote in message
...
In article ,
David Hansen writes:
On Sun, 27 Aug 2006 10:35:04 +0100 someone who may be "Jerry"
wrote this:-

Fridges and Freezers, computers and telecom / data handling, any
RCD
protected circuit, to name a few applications that benefit from
dedicated supplies.

Fridges and freezers don't really "benefit" from dedicated
supplies,
in most circumstances. The one circumstance where there might be
benefit is where an over-enthusiastic RCD disconnects the circuit
they are on.

When I do a rewire, I put in an non-RCD protected circuit. This
gets things like fridge, freezer, washing machine, oven (if 13A
plug type), central heating, burglar alarm (if not on lighting
circuit), any life support systems such as fish tank filters and
heaters (with a dedicated RCD), etc, i.e. all the things you
don't want to trip off because of some appliance's earth leak,
and which don't represent any significant safety risk due to
their own earth leakage (except fish tank, hence dedicated RCD).


But what then happens if one of those appliances takes the supply
out, such as washing machine or cooker say, if the owner is not at
home (quite likely in the case of a WM fault) one has a tank full of
dead fish on there return later than day? Also what if the owner
wants to move the fish tank, all a radial circuit requires is the RCD
moved within the distr' panel, not a re-wire as in the case of a ring
circuit...

In article ews.net,
"Jerry" writes:
But what then happens if one of those appliances takes the supply
out, such as washing machine or cooker say, if the owner is not at
home (quite likely in the case of a WM fault) one has a tank full of
dead fish on there return later than day? Also what if the owner
wants to move the fish tank, all a radial circuit requires is the RCD
moved within the distr' panel, not a re-wire as in the case of a ring
circuit...

These items are all separately protected by their 13A fuses.
It would require a failure of the wiring installation to take
them all out, which is a very rare occurance. Actually power
cuts are a much more likely cause to lose that whole circuit,
even in locations where they are rare.

--
Andrew Gabriel

"Andy Wade" wrote in message
...
Jerry wrote:

So you admit now that ring circuits can (and do) casue problems
by
the nature of their disgn?

Radial circuits can cause problems by the nature of their design
too.
In both cases the designer would have to have failed to consider
the use
to which the circuit is to be put.

The point I'm making is that one fault tripping the distr' panel
protection can and will take out every appliance on a ring
circuit
[1], with radial that can't happen.

Uh? - a trip on a radial circuit will also take out every appliance
on
that circuit.

Yes, but not the whole house, most would not be running more than two
or three appliances of any one radial in practice, it would also be
far more simple to re supply any non faulty appliances from other
radial circuits.

snip

There are some outlets that benefit from additional protection
(RCD,
Surge protection etc.), with radial circuits that protection can
be
placed within the distr' panel, rather than an unsightly socket
or
(worse) a plug-in device that's use might get forgotten or
ignored.

The same is true with ring circuits, indeed normal practice is now
for
all house ring circuits to be RCD protected at the distribution
board.

Hahahaahahahahhahahahahaha

Yes, one device trips the RCD and the rest get switched off at
source!


So you think that a 2 amp appliance protected with a 30 amp
device is
safer than if that protection was 15 amps or less when some
halfwit
overrides the plugs internal protection device?

This is an irrelevant point since a 13 A plug fuse perfectly well
protects a 0.5 mm^2 flex (for normal flex lengths), this being the
smallest flex in common use. The halfwit would need to fit a solid
quarter-inch bar in place of the fuse to cause any real danger!

Read what I said, 30 amps, not 13, there is no device in the plug
after a halfwit wraps a bit of 2.5mm wire (or what ever) around the
fuse retainers. If you have never seen such abuse you must have a
sheltered life!

snip

Nevertheless the ring concept is economical and convenient and has
certainly stood the test of time.

Another advantage of the ring is the relative ease of implementing
the
Section 607 high-integrity earthing requirements, where needed.


So it really come down to cost and ease for the contractor / builder
(were renovation / new construction is concerned anyway), not what
will make life easier for the owner later. I suspect that as 'home
automation' becomes more popular in renovated and new build the
radial circuit will become common again as each circuit is more
adaptable.

The message
from Andy Wade contains these words:

Most houses tend to have two rings, typically for ground floor and first
floor, and a third ring for the kitchen is now becoming common practice.
Only very small properties or ones wired a very long time ago will be
found with one ring circuit.

Like mine - which recently sprouted a new ring for the conservatory 'cos
I didn't want to add to an already busy ring. I could easily have done
with with a radial considering how little power is likely to be used in
there, but since the parents in law's skip was full of 2.5mm T&E I
couldn't think of a good reason not to.

--
Skipweasel
Pay no attention to that man behind the curtain.

"Andrew Gabriel" wrote in message
...
In article
ews.net,
"Jerry" writes:
But what then happens if one of those appliances takes the supply
out, such as washing machine or cooker say, if the owner is not
at
home (quite likely in the case of a WM fault) one has a tank full
of
dead fish on there return later than day? Also what if the owner
wants to move the fish tank, all a radial circuit requires is the
RCD
moved within the distr' panel, not a re-wire as in the case of a
ring
circuit...

These items are all separately protected by their 13A fuses.
It would require a failure of the wiring installation to take
them all out, which is a very rare occurance. Actually power
cuts are a much more likely cause to lose that whole circuit,
even in locations where they are rare.


Hmm, so MCB's are slower acting that re wireables?

On Sun, 27 Aug 2006 13:15:25 +0100 someone who may be "Jerry"
wrote this:-

Hmm, so MCB's are slower acting that re wireables?

All of a sudden re-wirable fuses have been introduced to the
discussion. Fascinating.


--
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 Sun, 27 Aug 2006 11:47:48 +0100 someone who may be "Jerry"
wrote this:-

So you admit now that ring circuits can (and do) casue problems by
the nature of their disgn?

I don't recall claiming that ring final circuits are perfect. Feel
free to point to a posting where I did. If you can't others can draw
their own conclusions.

All designs of circuit have advantages and disadvantages. Perfection
has yet to be achieved in any of them. However, in many
circumstances the ring final circuit is the best compromise.

The point I'm making is that one fault tripping the distr' panel
protection can and will take out every appliance on a ring circuit
[1], with radial that can't happen.

That point is obviously incorrect. A fault on a radial circuit which
causes the protective device at the consumer unit to open will, one
hopes, disconnect every appliance on that circuit. One could argue
that there may be fewer appliances on the radial circuit, but that
is not the point you made.

Also one has to think about
maintenance etc., with the ring circuit isolated many houses now only
have on useable socket, that on the cooker supply (if of fitted).

I have looked after a few such houses over the decades. However, I
have never yet been stopped from using power tools for works on the
system as a result.

There are some outlets that benefit from additional protection (RCD,
Surge protection etc.), with radial circuits that protection can be
placed within the distr' panel, rather than an unsightly socket or
(worse) a plug-in device that's use might get forgotten or ignored.

Such a device will still disconnect every appliance on the circuit,
one hopes, when it opens.

So, is you objection actually an objection to individual fuses for
equipment, rather then the final circuit wiring?

So you think that a 2 amp appliance protected with a 30 amp device is
safer than if that protection was 15 amps or less when some halfwit
overrides the plugs internal protection device?

I note that you have failed to answer the question.

Perhaps you can't or are not old enough to remember when houses were
wired with radial circuits?

Houses still are.

When radial circuits were used exclusively for general power
circuits there might typically be a 15A outlet in the living room
and a 5A outlet in each bedroom. That is very different from
conditions today.

People are not (and
have not for many years) being taught to question any more, but to
just accept what we are told.

I tend to agree. However, accepting what I am told without thinking
about it is not something I do.



--
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 in message
news
On Sun, 27 Aug 2006 11:47:48 +0100 someone who may be "Jerry"
wrote this:-

So you admit now that ring circuits can (and do) casue problems by
the nature of their disgn?

I don't recall claiming that ring final circuits are perfect. Feel
free to point to a posting where I did. If you can't others can
draw
their own conclusions.

Well seeing that you were making similar remark towards myself I
thought I would reply like wise, please feel free were I said that
radial circuits are perfect - all I have done is point out that there
is less chance of user abuse and when that abuse happens it is less
dangerous than when a ring circuit is in use.


All designs of circuit have advantages and disadvantages.
Perfection
has yet to be achieved in any of them. However, in many
circumstances the ring final circuit is the best compromise.

We will have to disagree on that.


The point I'm making is that one fault tripping the distr' panel
protection can and will take out every appliance on a ring circuit
[1], with radial that can't happen.

That point is obviously incorrect. A fault on a radial circuit
which
causes the protective device at the consumer unit to open will, one
hopes, disconnect every appliance on that circuit. One could argue
that there may be fewer appliances on the radial circuit, but that
is not the point you made.

As you said, it depends on what is connected, my point is that
critical applications (such as freezer or fish tank for example) can
easily be connected to their own supply in effect by the home owner -
that is not possible with a ring circuit.


Also one has to think about
maintenance etc., with the ring circuit isolated many houses now
only
have on useable socket, that on the cooker supply (if of fitted).

I have looked after a few such houses over the decades. However, I
have never yet been stopped from using power tools for works on the
system as a result.

Perhaps you are lucky...


There are some outlets that benefit from additional protection
(RCD,
Surge protection etc.), with radial circuits that protection can
be
placed within the distr' panel, rather than an unsightly socket or
(worse) a plug-in device that's use might get forgotten or
ignored.

Such a device will still disconnect every appliance on the circuit,
one hopes, when it opens.

Only those selected to be on that circuit, I hope no one would supply
anything that was critical on such a protected circuit unless it
expressly required such protection and certainly not with other
(unrelated) appliances.


So, is you objection actually an objection to individual fuses
for
equipment, rather then the final circuit wiring?

So you think that a 2 amp appliance protected with a 30 amp device
is
safer than if that protection was 15 amps or less when some
halfwit
overrides the plugs internal protection device?

I note that you have failed to answer the question.

I have answered the question.


Perhaps you can't or are not old enough to remember when houses
were
wired with radial circuits?

Houses still are.

When radial circuits were used exclusively for general power
circuits there might typically be a 15A outlet in the living room
and a 5A outlet in each bedroom. That is very different from
conditions today.

Your point is what exactly?

"David Hansen" wrote in message
...
On Sun, 27 Aug 2006 13:15:25 +0100 someone who may be "Jerry"
wrote this:-

Hmm, so MCB's are slower acting that re wireables?

All of a sudden re-wirable fuses have been introduced to the
discussion. Fascinating.


If you read the context, which you have (conveniently?) snipped, you
will see that the reply was in relation to remark about fuses fitted
within the BS1363 plug. Perhaps I should have just said 'fuse
wire'...

On Sun, 27 Aug 2006 17:30:55 +0100 someone who may be "Jerry"
wrote this:-

all I have done is point out that there
is less chance of user abuse

You may have made such an assertion. However, you have not made a
convincing argument to back up that assertion. If you would like to
do so then please do.

and when that abuse happens it is less
dangerous than when a ring circuit is in use.

You have not yet made a convincing argument to back up that
assertion.

As you said, it depends on what is connected, my point is that
critical applications (such as freezer or fish tank for example) can
easily be connected to their own supply in effect by the home owner -
that is not possible with a ring circuit.

Another incorrect assertion. Generally it will only be possible to
connect such equipment to separate circuits if each socket outlet is
connected to the consumer unit by its own radial circuit. That would
mean dozens of radial circuits in my house. If the usual approach in
radial wiring is adopted instead then in most rooms every socket
will be on the same circuit.

I have looked after a few such houses over the decades. However, I
have never yet been stopped from using power tools for works on the
system as a result.

Perhaps you are lucky...

I doubt it.

When radial circuits were used exclusively for general power
circuits there might typically be a 15A outlet in the living room
and a 5A outlet in each bedroom. That is very different from
conditions today.

Your point is what exactly?

Fairly obvious. One 15A and three 5A fuses for general power
circuits is very different from say 37 protective devices to feed
outlets individually, or even 11 protective devices to feed a small
number of outlets on each radial circuit. One of the far-sighted
options for adopting ring final circuits was to allow for a far
larger number of socket outlets than before, without the problems of
wiring them radially.




--
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 Sun, 27 Aug 2006 17:36:13 +0100 someone who may be "Jerry"
wrote this:-

Hmm, so MCB's are slower acting that re wireables?

All of a sudden re-wirable fuses have been introduced to the
discussion. Fascinating.

If you read the context, which you have (conveniently?) snipped,

It is available should anyone want to read it and smile. Your point
about the operating speed was in response to the following:-

"These items are all separately protected by their 13A fuses.
It would require a failure of the wiring installation to take
them all out, which is a very rare occurance. Actually power
cuts are a much more likely cause to lose that whole circuit,
even in locations where they are rare."

Your point has nothing to do with power cuts and neither does it
have anything to do with 13A fuses.

you
will see that the reply was in relation to remark about fuses fitted
within the BS1363 plug. Perhaps I should have just said 'fuse
wire'...

Fuses inside such plugs are not rewirable.


--
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 in message
...
On Sun, 27 Aug 2006 17:30:55 +0100 someone who may be "Jerry"
wrote this:-

all I have done is point out that there
is less chance of user abuse

You may have made such an assertion. However, you have not made a
convincing argument to back up that assertion. If you would like to
do so then please do.

I have indicated how easy it would be for some halfwit to bridge out
the fuse in a BS1363 plug, now tell me how easy it would be to swap /
bridge a CB in a distr' panel...


and when that abuse happens it is less
dangerous than when a ring circuit is in use.

You have not yet made a convincing argument to back up that
assertion.

I have, you are just in denial I suspect.


As you said, it depends on what is connected, my point is that
critical applications (such as freezer or fish tank for example)
can
easily be connected to their own supply in effect by the home
owner -
that is not possible with a ring circuit.

Another incorrect assertion. Generally it will only be possible to
connect such equipment to separate circuits if each socket outlet
is
connected to the consumer unit by its own radial circuit. That
would
mean dozens of radial circuits in my house. If the usual approach
in
radial wiring is adopted instead then in most rooms every socket
will be on the same circuit.

Against all sockets in the house / floor being on one protection
device when a ring is used...


I have looked after a few such houses over the decades. However,
I
have never yet been stopped from using power tools for works on
the
system as a result.

Perhaps you are lucky...

I doubt it.

Perhaps you just work in mansions or houses of multiple occupancy...


When radial circuits were used exclusively for general power
circuits there might typically be a 15A outlet in the living
room
and a 5A outlet in each bedroom. That is very different from
conditions today.

Your point is what exactly?

Fairly obvious. One 15A and three 5A fuses for general power
circuits is very different from say 37 protective devices to feed
outlets individually, or even 11 protective devices to feed a small
number of outlets on each radial circuit. One of the far-sighted
options for adopting ring final circuits was to allow for a far
larger number of socket outlets than before, without the problems
of
wiring them radially.


Except that all outlets on the ring, sometimes meaning all power in
the house except the cooker in older properties, fail due to a fault,
not forgetting that a 2 amp appliance can easily become grossly under
protected.

Ring circuits were brought in to save on expencive wire, remember
when alloy wire as tried in an attempt to keep cost down, and to a
leaser extent save on labour costs. At the time, ring circuits made
sense because the there were fewer appliances in the house than now -
it would be quite easy to over load a single ring circuit now days -
hence why, even in medium sized houses, we now find two or more ring
circuits having to be installed.

"David Hansen" wrote in message
...
On Sun, 27 Aug 2006 17:36:13 +0100 someone who may be "Jerry"
wrote this:-

Hmm, so MCB's are slower acting that re wireables?

All of a sudden re-wirable fuses have been introduced to the
discussion. Fascinating.

If you read the context, which you have (conveniently?) snipped,

It is available should anyone want to read it and smile. Your point
about the operating speed was in response to the following:-

"These items are all separately protected by their 13A fuses.
It would require a failure of the wiring installation to take
them all out, which is a very rare occurance. Actually power
cuts are a much more likely cause to lose that whole circuit,
even in locations where they are rare."

Your point has nothing to do with power cuts and neither does it
have anything to do with 13A fuses.

you
will see that the reply was in relation to remark about fuses
fitted
within the BS1363 plug. Perhaps I should have just said 'fuse
wire'...

Fuses inside such plugs are not rewirable.


Nor does trolling, a sure sign that you are loosing the argument and
know it, my point was the speed of tripping between relative
protection devices, are you implying that an MCB is slower than a
cartridge fuse?

Dave Plowman (News) wrote:
foxlj wrote:
I've just moved into a new flat and in the lounge, next to every
standard plug socket, there are sockets with three round holes in a
triangle (like a standard plug socket but with roung holes rather than
rectangular). Can anyone tell me what they are?

Almost certainly one of these - it gives the distance between pins so
measure your sockets to match up.
http://www.tlc-direct.co.uk/Main_Ind...s_2/index.html

There is also a dimmer switch that is not connected to anything, so
could they be for lighting? I have tried european plugs but they do not
fit. Any ideas would be much appreciated...

Commonly used for lighting circuits at floor level - things like table
lamps which you wish to switch or dim from a central point. Avoids
plugging the Hoover in and blowing up the dimmer. ;-)

Unless she lives in Italy

http://www.marcucci.it/english/prodo...da.asp?ID=3773

P.

On Sun, 27 Aug 2006 21:01:08 +0100 someone who may be "Jerry"
wrote this:-

I have indicated how easy it would be for some halfwit to bridge out
the fuse in a BS1363 plug,

That is irrelevant to your assertion, because there is the same risk
of someone doing that, no matter how the final circuits are wired.

now tell me how easy it would be to swap /
bridge a CB in a distr' panel...

You are basing your assertion on different types of protective
device being used for different types of final circuit. However,
that is false. With the exception of a standard 30/32A radial
circuit, any type of protective device may be used on any type of
circuit. Each sort of protective device may be abused in various
ways, for example a Wylex style MCB can have a wire wrapped round
the pins.

I have, you are just in denial I suspect.

Excellent, more personal abuse. Such abuse is usually the resort of
those who don't have better arguments.

If the usual approach in
radial wiring is adopted instead then in most rooms every socket
will be on the same circuit.

Against all sockets in the house / floor being on one protection
device when a ring is used...

Do you normally run the leads of freezers and fish tanks into
another room? Do you think this would be a good idea if each room
had a radial circuit supplying all the sockets in that room?

Except that all outlets on the ring, sometimes meaning all power in
the house except the cooker in older properties, fail due to a fault,

Only a fault in the fixed wiring. Such faults rarely just happen,
they are usually caused by humans doing things like drilling into
the cable.

not forgetting that a 2 amp appliance can easily become grossly under
protected.

Easily? Well someone could use the wrong fuse. However, even if they
do a 13A fuse near the appliance will protect it far more than say a
20A fuse at the consumer unit. If the radial circuit has a 30/32A
protective device then there is no difference to a ring circuit with
the same protective device.

I note that we are still waiting for an answer as to whether your
objection is to individually fused appliances or fixed wiring
systems. Unless you answer that question I might soon conclude that
you are trolling.

it would be quite easy to over load a single ring circuit now days

If the protective device fails to operate. Time, as well as current,
determines what is dangerous.

The same is true of radial circuits of course. If the protective
device does operate other then once in a blue moon then the designer
has failed to make a suitable allowance for diversity, whether the
circuit is radial or a ring.



--
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 Sun, 27 Aug 2006 21:05:30 +0100 someone who may be "Jerry"
wrote this:-

Nor does trolling,

You are the one who seems to be doing that.

a sure sign that you are loosing the argument

Believe that if you like.

and know it,

Ah, mind reading. Added to the personal attacks that paints an
interesting picture.

my point was the speed of tripping between relative
protection devices, are you implying that an MCB is slower than a
cartridge fuse?

Ah, now we are talking about cartridge fuses, not rewirable fuses. I
note the twisting and turning.

Is an MCB slower than a cartridge fuse? The answer is that usually
it is, assuming we are comparing devices of the same rating and type
of duty at the same short-circuit current. Thinking that an MCB
operates more quickly than a cartridge fuse is a common
misconception, but it is still a misconception. All the fuse element
has to do is melt, a rapid operation at high currents. By contrast
the magnetic coil of an MCB has to operate several mechanical
linkages, with their attendant friction and inertia, to move the
contacts far enough apart to quench the arc. That is assuming that
it can quench the arc.

The situation in which an MCB may operate more quickly than a
cartridge fuse is a relatively small overcurrent of long duration,
when the thermal trip of an MCB may operate before a fuse does.
However, such a situation is to do with a poor estimation of
diversity and hence the protection of the fixed wiring from
overload, rather than the protection of appliances and their wiring
that you were talking about.

That is comparing protective devices at the same position, so one is
just comparing the speed of operation at particular currents.
Discrimination between protective devices of different types and
ratings at different positions is far more complicated. However,
until you say whether you want a fuse in the plug or not that sort
of discussion is not worth entering into.



--
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