Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

No.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

Even if te light fiffing istelf carries the nain circuit it is
coinventional to run TWO cable to the switch so as NOT to have s bcak
wire being swtiched live.



This means only one cable is connected to the consumer unit.

Yes

I
believe a red sheath should be fitted to the black wire at the switch.


I believe its not done like that in best practice, I never have.

In the limit you need to carry live, switched-live and earth to the
switch as you have surmised, but I do not think that normal T & E colors
are used in that case.


(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.



--
Theres a mighty big difference between good, sound reasons and reasons
that sound good.

Burton Hillis (William Vaughn, American columnist)

On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

Even if te light fiffing istelf carries the nain circuit it is
coinventional to run TWO cable to the switch so as NOT to have s bcak
wire being swtiched live.



This means only one cable is connected to the consumer unit.

Yes

Â* I
believe a red sheath should be fitted to the black wire at the switch.


I believe its not done like that in best practice, I never have.

In the limit you need to carry live, switched-live and earth to the
switch as you have surmised, but I do not think that normal T & E colors
are used in that case.


(*)Â* Although I refer to red and black, I appreciate these may be
brown and blue.Â* I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.


"Loop in" wiring is AFAIK (a) dead common, (b) still perfectly
acceptable and (c) what the OP seems to have.

http://wiki.diyfaq.org.uk/index.php/...Loop-in_Wiring




--
Robin
reply-to address is (intended to be) valid

The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

Even if te light fiffing istelf carries the nain circuit it is
coinventional to run TWO cable to the switch so as NOT to have s bcak
wire being swtiched live.



This means only one cable is connected to the consumer unit.

Yes

Â* I
believe a red sheath should be fitted to the black wire at the switch.


I believe its not done like that in best practice, I never have.

In the limit you need to carry live, switched-live and earth to the
switch as you have surmised, but I do not think that normal T & E colors
are used in that case.


(*)Â* Although I refer to red and black, I appreciate these may be
brown and blue.Â* I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.



In Australia generally, because all lighting for quite a while has to
have an earth present they mainly run a twin +E through every light
point (A N E )and then drop a twin down to the switch from each point
for standard lighting points.
2 way requires a wire between switches.
Rarely do you need a neutral at the switch point

On 29/09/18 10:53, Robin wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

Even if te light fiffing istelf carries the nain circuit it is
coinventional to run TWO cable to the switch so as NOT to have s bcak
wire being swtiched live.



This means only one cable is connected to the consumer unit.

Yes

Â*Â* I
believe a red sheath should be fitted to the black wire at the switch.


I believe its not done like that in best practice, I never have.

In the limit you need to carry live, switched-live and earth to the
switch as you have surmised, but I do not think that normal T & E
colors are used in that case.


(*)Â* Although I refer to red and black, I appreciate these may be
brown and blue.Â* I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.


"Loop in" wiring is AFAIK (a) dead common, (b) still perfectly
acceptable and (c) what the OP seems to have.

http://wiki.diyfaq.org.uk/index.php/...Loop-in_Wiring





I am amazed.


--
Climate Change: Socialism wearing a lab coat.

On 29/09/2018 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.



There are various ways to do lighting

http://wiki.diyfaq.org.uk/index.php/...Loop-in_Wiring

it is though just usually a radial from the CU.

--
Adam

On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes


I think you mean NO

Ahem, there are always live and neutral in all my ceiling roses even if the
switch is off, and to me this disproves your hypothesis completely

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Scott" wrote in message
...
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

You obviously have a keyboard like mine with a couple of sicky eys
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"The Natural Philosopher" wrote in message
news
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

No.

In genereal the cable goes from te curcuit to the stich, and then on again
to the next swich and cables are run from te switch to te light fitting.
So the switch has THREE cables entering it.

Even if te light fiffing istelf carries the nain circuit it is
coinventional to run TWO cable to the switch so as NOT to have s bcak wire
being swtiched live.



This means only one cable is connected to the consumer unit.

Yes

I
believe a red sheath should be fitted to the black wire at the switch.


I believe its not done like that in best practice, I never have.

In the limit you need to carry live, switched-live and earth to the switch
as you have surmised, but I do not think that normal T & E colors are used
in that case.


(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.



--
There's a mighty big difference between good, sound reasons and reasons
that sound good.

Burton Hillis (William Vaughn, American columnist)

On Saturday, 29 September 2018 09:29:57 UTC+1, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

Pretty much. The other way to do it is run the T&E from the CU to each switch, then T&E carrying E, N, switched L to the light fitting.


NT

On Sat, 29 Sep 2018 17:03:41 +0100, "Brian Gaff"
wrote:

Ahem, there are always live and neutral in all my ceiling roses even if the
switch is off, and to me this disproves your hypothesis completely

Depends on your interpretation of my hypothesis. When I said the
action takes place on the red, I did not mean no return path was
needed. I do have some clue about electricity. I meant the
'diversion' and switching takes place on the red.

On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.

Even if te light fiffing istelf carries the nain circuit it is
coinventional to run TWO cable to the switch so as NOT to have s bcak
wire being swtiched live.

That's even less common (to the point I have never seen it done)

This means only one cable is connected to the consumer unit.

Yes

Â* I
believe a red sheath should be fitted to the black wire at the switch.

Yup

I believe its not done like that in best practice, I never have.

Its is a regs requirement, since you are using a wire for a purpose its
colour would not indicate otherwise. I will agree its frequently missing
however, but it should be there.

In the limit you need to carry live, switched-live and earth to the
switch as you have surmised, but I do not think that normal T & E colors
are used in that case.

You can get a T&E with two red/brown conductors, but its rarely used
since normal colours and over marking is acceptable.



--
Cheers,

John.

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

In article ,
writes
On Saturday, 29 September 2018 09:29:57 UTC+1, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

Pretty much. The other way to do it is run the T&E from the CU to each
switch, then T&E carrying E, N, switched L to the light fitting.


NT
Would you believe I have both in my house. The old original part is L
and N to the ceiling rose. The extension was wired to the switch. Done
by a fully certified electrician of course - well actually done by his
apprentice, about the same standard as Adams. I had to go round a
tighten up at least 3 connections within the week.
--
bert

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

--
Adam

On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

On Monday, 1 October 2018 21:31:37 UTC+1, Scott wrote:
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

There are at least 2 ways to wire sockets


NT

On Mon, 1 Oct 2018 13:46:27 -0700 (PDT), wrote:

On Monday, 1 October 2018 21:31:37 UTC+1, Scott wrote:
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

There are at least 2 ways to wire sockets

Are there two ways to wire a ring main? Do you mean with or without
spurs, perhaps?

Scott wrote:
Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

Because usually things on a ring circuit don't have remote switches. If
all your lights have built in switches, there's only one way to wire a
lighting circuit. If all the sockets on your ring have separate
switches, they can be wired the same two (or three really) ways. But
lights normally have separate switches, and sockets normally don't.

A simpler version is that there's four ways to wire a switch to a
switched load:
1) The switch is built in to the end accessory.
2) "Junction box" wiring - the "main line" of the power circuit connects
to a junction box. Live goes to the switch, switched live comes back,
switched live and neutral go to the load.
3) "loop in" wiring" - the main line of the power circuit goes to the
load (light) which has an extra terminal - effectively a built-in
junction box. Live goes to the switch and switched live comes back.
4) I don't think this one has an official name - the main line of the
power circuit goes to the switch. Switched live and neutral go to the
load.

Note that two or more of these - even all four - can be mixed on a
single circuit. None are more correct than the others but some are more
common. Lighting circuits usually use 2 or 3, sometimes 4. Power
circuits use 1, though 4 is used in kitchens (where there's a switch
above the worktop and a socket below).

Mike

On 01/10/2018 21:31, Scott wrote:
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

Perhaps a better comparison with socket circuits in general rather than
a ring specifically. Then there are several ways of doing the sockets.
However socket circuits are inherently similar in that they don't
usually involve remote switching (save for a few under counter sockets
in the kitchen), or a remote load from the main termination (although
you could argue a spur is such a thing).



--
Cheers,

John.

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

On 01/10/2018 21:03, ARW wrote:
On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Probably the influence of lots of imported fancy light fittings with
inadequate terminal space for traditional loop in style wiring, and
demise of the common ceiling rose.

I find switch loop through quite handy for surface wiring applications,
and exterior lights, where a single cable connection is neater.


--
Cheers,

John.

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

"ARW" wrote in message
...
On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Any idea why it is becoming more common ?

"Scott" wrote in message
...
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

Because with a lighting circuit, you can loop thru the roses or loop thru
the
switches. There is no equivalent with a ring main, the ring main is the
loop.

On Monday, 1 October 2018 22:04:17 UTC+1, Scott wrote:
On Mon, 1 Oct 2018 13:46:27 -0700 (PDT), tabbypurr wrote:
On Monday, 1 October 2018 21:31:37 UTC+1, Scott wrote:

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

There are at least 2 ways to wire sockets

Are there two ways to wire a ring main? Do you mean with or without
spurs, perhaps?

There's ring & radial. There's 20A & 32A. There's spurs, no spurs and all spurs. There's T&E and MICC. There's flush & surface. How many ways do you want to slice it?

There are also obsolete methods very ocasionally found, eg a ring run on 2x 15A fuses, or even more rarely, possibly to the point of never, 4x 15A fuses. Or even more obsoletely, flats each on a single 5A fuse. Seen that one. And no, the electric ovens were not thermostatic.


NT

On 02/10/2018 00:34, Rod Speed wrote:


"Scott" wrote in message
...
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting
circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then
through
the light bulb to the main black wire.Â* The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

Because with a lighting circuit, you can loop thru the roses or loop
thru the
switches. There is no equivalent with a ring main, the ring main is the
loop.

If you use 4.0mm^2 T+E you can still do a loop through with sockets.

I also thought 18ed regs suggests that some care should be exercised so
that one end of the ring isn't overloaded. BICBW

On Tue, 2 Oct 2018 09:34:37 +1000, cantankerous trolling senile geezer Rot
Speed blabbered, again:


Because with a lighting circuit, you can loop thru the roses or loop thru
the
switches. There is no equivalent with a ring main, the ring main is the
loop.

Someone needs to punch your stupid senile face until your ears start
ringing, senile Ozzie cretin!

--
"Anonymous" to trolling senile Rot Speed:
"You can **** off as you know less than pig **** you sad
little ignorant ****."
MID:

On Tue, 2 Oct 2018 09:32:39 +1000, cantankerous trolling senile geezer Rot
Speed blabbered, again:



Becoming more common all the time.

Any idea why it is becoming more common ?

YOU tell us, Mr Know-it-all! BG

--
dennis@home to know-it-all Rot Speed:
"You really should stop commenting on things you know nothing about."
Message-ID:

On Saturday, 29 September 2018 09:29:57 UTC+1, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

The question only makes sense if the circuit is wired using "three plate/terminal" ceiling roses when live, neutral and switch wire is present.

Normally the L+N goes from CU to nearest ceiling rose to the next until the last/most remote one and then stops.

But in principle you could wire a ring main.
However, the currents involved are so low it would be pointless.
Especially these days with LED lights.

On 01/10/18 21:31, Scott wrote:

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?


There's at least 3 general ways:

1) Ceiling rose loopin-loopout. Supply goes from rose to rose. Switch
drop goes from rose to switch.

Pro: Simple, easy to get at, roses have all the terminals needed.

Con: Works if you like having nothing but flex drop lights.
Random other light fittings may not have the space needed for all the
terminations.

2) Switch loopin-loopout. Seen this once. Works with deeper backboxes.
Needs a loose connector for the neutral. Not common IME.

Pro: Accessible
Con: Generally 3+ cables to any given switch. Adds a lot to the overall
cable length from end to end.

3) Star wired from junction boxes (what I did). 4 sets of boxes in
accessible attic locations. Very uncommon in the UK, though I think some
countries do this more.

Pro: All terminals accessible and very easy to modify.
Very good if you want to include remote control modules for
ZWave(etc) which is why I did it like this.
Con: More cable

On Mon, 1 Oct 2018 16:36:54 -0700 (PDT), wrote:

On Monday, 1 October 2018 22:04:17 UTC+1, Scott wrote:
On Mon, 1 Oct 2018 13:46:27 -0700 (PDT), tabbypurr wrote:
On Monday, 1 October 2018 21:31:37 UTC+1, Scott wrote:

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

There are at least 2 ways to wire sockets

Are there two ways to wire a ring main? Do you mean with or without
spurs, perhaps?

There's ring & radial. There's 20A & 32A. There's spurs, no spurs and all spurs. There's T&E and MICC. There's flush & surface. How many ways do you want to slice it?

There are also obsolete methods very ocasionally found, eg a ring run on 2x 15A fuses, or even more rarely, possibly to the point of never, 4x 15A fuses. Or even more obsoletely, flats each on a single 5A fuse. Seen that one. And no, the electric ovens were not thermostatic.

I did ask about ring mains but I take your point.

On Tue, 2 Oct 2018 00:26:28 -0700 (PDT), harry
wrote:

On Saturday, 29 September 2018 09:29:57 UTC+1, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

The question only makes sense if the circuit is wired using "three plate/terminal" ceiling roses when live, neutral and switch wire is present.

Normally the L+N goes from CU to nearest ceiling rose to the next until the last/most remote one and then stops.

But in principle you could wire a ring main.
However, the currents involved are so low it would be pointless.
Especially these days with LED lights.

Thanks. It's getting complicated so I'm going to 'clone' what's there
already (and stand well clear!).

On Tuesday, 2 October 2018 08:26:30 UTC+1, harry wrote:
On Saturday, 29 September 2018 09:29:57 UTC+1, Scott wrote:

Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)? All the action takes place on the red (*)
wire. In each room there are two drop cables: one to the switch and
one to the light fitting. The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

This means only one cable is connected to the consumer unit. I
believe a red sheath should be fitted to the black wire at the switch.

(*) Although I refer to red and black, I appreciate these may be
brown and blue. I have ignored the earth but I assume every earth
should be connected to every other earth at every opportunity.

The question only makes sense if the circuit is wired using "three plate/terminal" ceiling roses when live, neutral and switch wire is present.

Normally the L+N goes from CU to nearest ceiling rose to the next until the last/most remote one and then stops.

But in principle you could wire a ring main.
However, the currents involved are so low it would be pointless.
Especially these days with LED lights.

The point of rings, other than using thinner cable, is safety & reliability..

If we weren't buried in red tape the UK would probably switch to bell wire for lighting with thicker insulation. The ubiquity of LED & CFL bulbs makes 100w per fitting an obsolete requirement. The widespread use of double insulated fittings & RCDs along with an all time total of 1 death from a light fitting shock makes lighting earthing redundant.


NT

Wrote in message:
On Monday, 1 October 2018 21:31:37 UTC+1, Scott wrote:
On Mon, 1 Oct 2018 21:03:57 +0100, ARW
wrote:

On 29/09/2018 19:17, John Rumm wrote:
On 29/09/2018 10:04, The Natural Philosopher wrote:
On 29/09/18 09:29, Scott wrote:
Simplistically, am I right in understanding that a lighting circuit is
linear (not a ring main)?

Yes

All the action takes place on the red (*)
wire.
Yes

In each room there are two drop cables: one to the switch and
one to the light fitting.

Yes ot no depending

The electricity goes from the ceiling to
the switch then back to the light fitting (via the black) then through
the light bulb to the main black wire. The same is repeated in each
room.

No.

Erm, yes! That's the way most loop-in systems are wired. Ideally with
some coloured sleeving over the neutral wires where they are being
re-purposed as switched lives.

In genereal the cable goes from te curcuit to the stich, and then on
again to the next swich and cables are run from te switch to te light
fitting. So the switch has THREE cables entering it.

That is another method ("switch loop in"), but its far less common.


Becoming more common all the time.

Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?

There are at least 2 ways to wire sockets


NT


Let me guess - the right way & the wrong way?
--
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 02/10/18 12:03, wrote:

If we weren't buried in red tape the UK would probably switch to bell wire for lighting with thicker insulation. The ubiquity of LED & CFL bulbs makes 100w per fitting an obsolete requirement. The widespread use of double insulated fittings & RCDs along with an all time total of 1 death from a light fitting shock makes lighting earthing redundant.

You still need to be able to trip a 6A type B breaker in 0.4S (typical
lighting circuit, not all possible permitted) - and bell wire isn;t
going to do that. Given 1mm2 is pretty small and the CPC takes almost no
space, it would seem to be an unnecessary change.

On 02/10/2018 00:46, Fredxx wrote:

If you use 4.0mm^2 T+E you can still do a loop through with sockets.

I also thought 18ed regs suggests that some care should be exercised so
that one end of the ring isn't overloaded. BICBW

4mm ring circuits are quite common in schools, industrial units, big
houses etc due the the length of cable they need.

The balancing of a ring so that one end is not overloaded has been
around, I would presume, since the use of the ring circuits. It
certainly is part of the 16th edition. Of course a 4mm cabled ring does
away with this part of the design.

--
Adam

On 01/10/2018 21:31, Scott wrote:


Why are there several ways to wire a lighting circuit when there is
only one way to wire a ring main?


I would suggest that this is down to the use of historic cables.

When electric was first introduced into houses it was quite common to
use conduit and the cotton covered cables in singles.

When T&E came alone the use of conduit disappeared and the loop in loop
out at the light fitting became the preferred method. With the conduit
method, to save cable and conduit space you would loop the permanent
live at the switches and the neutral at the lights. However singles
wiring was still carried on by some electricians who liked it (the
picture Terry Casey drew the picture for in the Wiki
http://wiki.diyfaq.org.uk/index.php/...ngle_.26_Earth)



--
Adam

On Tuesday, 2 October 2018 14:24:28 UTC+1, Tim Watts wrote:
On 02/10/18 12:03, tabbypurr wrote:

If we weren't buried in red tape the UK would probably switch to bell wire for lighting with thicker insulation. The ubiquity of LED & CFL bulbs makes 100w per fitting an obsolete requirement. The widespread use of double insulated fittings & RCDs along with an all time total of 1 death from a light fitting shock makes lighting earthing redundant.

You still need to be able to trip a 6A type B breaker in 0.4S (typical
lighting circuit, not all possible permitted) - and bell wire isn;t
going to do that.

no, it needs to be able to trip a 1A breaker in 0.4s. Or 1.5A etc.


Given 1mm2 is pretty small and the CPC takes almost no
space, it would seem to be an unnecessary change.

the lighting cpc is redundant now. The outer insulation is redundant as long as the cable stays hidden in walls, floor spaces etc. Its wasted cost, materials, fuel, emissions etc. No-one plugs their iron into the bulb socket anymore.


NT

On 02/10/18 19:50, wrote:
On Tuesday, 2 October 2018 14:24:28 UTC+1, Tim Watts wrote:
On 02/10/18 12:03, tabbypurr wrote:

If we weren't buried in red tape the UK would probably switch to bell wire for lighting with thicker insulation. The ubiquity of LED & CFL bulbs makes 100w per fitting an obsolete requirement. The widespread use of double insulated fittings & RCDs along with an all time total of 1 death from a light fitting shock makes lighting earthing redundant.

You still need to be able to trip a 6A type B breaker in 0.4S (typical
lighting circuit, not all possible permitted) - and bell wire isn;t
going to do that.

no, it needs to be able to trip a 1A breaker in 0.4s. Or 1.5A etc.

Tell me - where do you buy these 1A Type B CU breakers?

the lighting cpc is redundant now. The outer insulation is redundant as long as the cable stays hidden in walls, floor spaces etc. Its wasted cost, materials, fuel, emissions etc. No-one plugs their iron into the bulb socket anymore.


The main purpose of the the sheath is to protect the *insulation* on the
conductors - especially during install when the cable is rough handled,
pulled through splintery holes, clipped to rough masonry etc.

There is no way getting rid of the sheath is a good idea.

On Tuesday, 2 October 2018 20:07:57 UTC+1, Tim Watts wrote:
On 02/10/18 19:50, tabbypurr wrote:
On Tuesday, 2 October 2018 14:24:28 UTC+1, Tim Watts wrote:
On 02/10/18 12:03, tabbypurr wrote:

If we weren't buried in red tape the UK would probably switch to bell wire for lighting with thicker insulation. The ubiquity of LED & CFL bulbs makes 100w per fitting an obsolete requirement. The widespread use of double insulated fittings & RCDs along with an all time total of 1 death from a light fitting shock makes lighting earthing redundant.

You still need to be able to trip a 6A type B breaker in 0.4S (typical
lighting circuit, not all possible permitted) - and bell wire isn;t
going to do that.

no, it needs to be able to trip a 1A breaker in 0.4s. Or 1.5A etc.

Tell me - where do you buy these 1A Type B CU breakers?

I'm pretty sure the usual mcb/cu suppliers would produce them if they became part of a permitted circuit configuration.

the lighting cpc is redundant now. The outer insulation is redundant as long as the cable stays hidden in walls, floor spaces etc. Its wasted cost, materials, fuel, emissions etc. No-one plugs their iron into the bulb socket anymore.


The main purpose of the the sheath is to protect the *insulation* on the
conductors - especially during install when the cable is rough handled,
pulled through splintery holes, clipped to rough masonry etc.

There is no way getting rid of the sheath is a good idea.

Some is, some isn't. 6A to lighting points just isn't needed any more.


NT

On 02/10/18 21:00, wrote:

There is no way getting rid of the sheath is a good idea.

Some is, some isn't. 6A to lighting points just isn't needed any more.

That's not a factor of the sheath though. And removing the CPC is
pointless in real terms (I don't trust RCDs - they are *nice to have*
but I like having a second layer of protection against the live
contacting the metalwork on a Class I fitting.) 1mm2 cable is
inexpensive, smallish and easy to route. So you're not really solving
any real problem.

On 02/10/2018 21:00, wrote:
On Tuesday, 2 October 2018 20:07:57 UTC+1, Tim Watts wrote:
On 02/10/18 19:50, tabbypurr wrote:
On Tuesday, 2 October 2018 14:24:28 UTC+1, Tim Watts wrote:
On 02/10/18 12:03, tabbypurr wrote:

If we weren't buried in red tape the UK would probably switch to bell wire for lighting with thicker insulation. The ubiquity of LED & CFL bulbs makes 100w per fitting an obsolete requirement. The widespread use of double insulated fittings & RCDs along with an all time total of 1 death from a light fitting shock makes lighting earthing redundant.

You still need to be able to trip a 6A type B breaker in 0.4S (typical
lighting circuit, not all possible permitted) - and bell wire isn;t
going to do that.

no, it needs to be able to trip a 1A breaker in 0.4s. Or 1.5A etc.

Tell me - where do you buy these 1A Type B CU breakers?

I'm pretty sure the usual mcb/cu suppliers would produce them if they became part of a permitted circuit configuration.

the lighting cpc is redundant now. The outer insulation is redundant as long as the cable stays hidden in walls, floor spaces etc. Its wasted cost, materials, fuel, emissions etc. No-one plugs their iron into the bulb socket anymore.


The main purpose of the the sheath is to protect the *insulation* on the
conductors - especially during install when the cable is rough handled,
pulled through splintery holes, clipped to rough masonry etc.

There is no way getting rid of the sheath is a good idea.

Some is, some isn't. 6A to lighting points just isn't needed any more.



And your suggestion for the 19th edition of the regs is?


--
Adam