I fear I'm over thinking it, but any way of wiring a lighting circuit
seems to come with disadvantages...

1. standard UK loop-in power at each light fitting
advantages: standard, have unswitched power available at fitting for
future e.g. ceiling fan/light etc
disadvantages: many modern light fittings don't have enough terminals,
or much space to add them

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

3. junction boxes in the ceiling
advantages: single wire to each light fitting and each switch
disadvantages: junction boxes are supposed to be accessible, but most
won't be in practice. won't have unswitched power anywhere except
junction box

4. wire singles: neutral looped into fittings, live looped into
switches
advantages: saves copper! fewer wires in general
disadvantages: induction loop interference, can you still buy cheap
singles, won't have unswitched power anywhere

5. any other options?

6. mix and match the above as convenient
advantages: ?
disadvantages: confusing. will probably end up without unswitched
power where I need it!


I know in the past I lived in a house with standard loop-in wiring to
each light fitting, and had to put junction boxes in the ceiling to
nicely accommodate several new light fittings with only LNE terminals.

Thoughts?

Cheers,
David.

On Jun 2, 10:36*am, David Robinson
wrote:
I fear I'm over thinking it, but any way of wiring a lighting circuit
seems to come with disadvantages...

1. standard UK loop-in power at each light fitting
advantages: standard, have unswitched power available at fitting for
future e.g. ceiling fan/light etc

Fan feed is a fairly big point imho, I'd look to include unswitched
live at the ceiling lighting points whatever scheme is used.


disadvantages: many modern light fittings don't have enough terminals,
or much space to add them

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

If you did it would suffer one of the 2 downsides of the Carter
system, which was outlawed in the 1930s. Ie that a switch failure is
liable to short out the supply, its a fire risk.


3. junction boxes in the ceiling
advantages: single wire to each light fitting and each switch
disadvantages: junction boxes are supposed to be accessible, but most
won't be in practice.

With a tool they could be, ie by unscrewing the light fitting first.
Also one can solder inside the jbox, fit the wires in the screw
connectors as normal, but leaving long tails, and solder those. The
screw cons then provide mechanical restraint for the solder joints.


won't have unswitched power anywhere except
junction box

you can have it anywhere you want by using an extra cable core.


4. wire singles: neutral looped into fittings, live looped into
switches
advantages: saves copper! fewer wires in general
disadvantages: induction loop interference, can you still buy cheap
singles, won't have unswitched power anywhere

again you get L, swL and N anywhere you want by fitting the necessary
singles to provide it.


5. any other options?

well, yes ... I doubt its what you'd want though.


6. mix and match the above as convenient
advantages: ?
disadvantages: confusing. will probably end up without unswitched
power where I need it!

I know in the past I lived in a house with standard loop-in wiring to
each light fitting, and had to put junction boxes in the ceiling to
nicely accommodate several new light fittings with only LNE terminals.

Thoughts?

Cheers,
David.

NT

In article ,
David Robinson writes:

5. any other options?

When I rewired a house for home automation, I ran all the switch
and lighting point wires back to central connection points (actually
consumer unit shells, because the DIN rail made it easy to mount
X10 dimmers and relays). It's easy to change the way things are
switched, rather like a Cat5 wiring closet, and (important point
for selling) it's easy to strip out the home automation control
and revert to manual operation.

All switch drop cables are triple and earth, which allows either
to get a neutral to the switch or to add a second switch in the
future. Again, many of the lighting points are triple and earth,
for future flexibility.

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

On 02/06/10 10:36, David Robinson wrote:
I fear I'm over thinking it, but any way of wiring a lighting circuit
seems to come with disadvantages...

1. standard UK loop-in power at each light fitting
advantages: standard, have unswitched power available at fitting for
future e.g. ceiling fan/light etc
disadvantages: many modern light fittings don't have enough terminals,
or much space to add them

Agreed - don't like this as it bones you if SWMBO gets one of those Ikea
fittings with sod all space for terminals.

Pity they don't do a flush ceiling rose but you could DIY one with a
round dry lining box and terminal strip...

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless it
says so) which would result in a rather noticeable bang followed by no
lights.


3. junction boxes in the ceiling
advantages: single wire to each light fitting and each switch
disadvantages: junction boxes are supposed to be accessible, but most
won't be in practice. won't have unswitched power anywhere except
junction box

Hager-Ashley maintenance free JBs with spring terminals. The jury is
still out on their longevity but the regs allow these, because the
manufacturer rates them as fit for purpose. But I personally wouldn't
stick then under tiles or laminate just in case! Under floorboards is
fine, and under easily liftable floorboards, you could use a screwed JB
anyway.

4. wire singles: neutral looped into fittings, live looped into
switches
advantages: saves copper! fewer wires in general
disadvantages: induction loop interference, can you still buy cheap
singles, won't have unswitched power anywhere

And you'd need either full *continuous*[1] conduit/trunking or double
insulated singles. Unenclosed single-insulated singles (wibble) are NOT
allowed anywhere.

[1] That means continuous, no 1" gap by the light because it was too hard...

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

As all my lighting is run mostly on one level, with a dormer conversion,
I've made up 4 large junction boxes with DIN rain and DIN terminals. One
in each quadrant of the house, in the corner voids behind the dormer
room walls (where there are large accessible voids).

Not for everyone - costs more (could have used lots of regular JBs for
the same effect, but I want somewhere to stick relays for a bit of
remote control) and needs more cable. However, not *that* much more in
my case due to the layout.

6. mix and match the above as convenient
advantages: ?
disadvantages: confusing. will probably end up without unswitched
power where I need it!

Another option - permanant power to all lights and fit radio controlled
units to each one. No cables to the switches. Cool, but costs a fortune.
getting more popular though - check out Homebase and B&Q - they seem to
be increasing the range of these units.


I know in the past I lived in a house with standard loop-in wiring to
each light fitting, and had to put junction boxes in the ceiling to
nicely accommodate several new light fittings with only LNE terminals.

Thoughts?

Cheers,
David.


--
Tim Watts

Hung parliament? Rather have a hanged parliament.

On 2 June, 10:36, David Robinson
wrote:
I fear I'm over thinking it, but any way of wiring a lighting circuit
seems to come with disadvantages...

1. standard UK loop-in power at each light fitting
advantages: standard, have unswitched power available at fitting for
future e.g. ceiling fan/light etc
disadvantages: many modern light fittings don't have enough terminals,
or much space to add them

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

3. junction boxes in the ceiling
advantages: single wire to each light fitting and each switch
disadvantages: junction boxes are supposed to be accessible, but most
won't be in practice. won't have unswitched power anywhere except
junction box

4. wire singles: neutral looped into fittings, live looped into
switches
advantages: saves copper! fewer wires in general
disadvantages: induction loop interference, can you still buy cheap
singles, won't have unswitched power anywhere

5. any other options?

6. mix and match the above as convenient
advantages: ?
disadvantages: confusing. will probably end up without unswitched
power where I need it!

I know in the past I lived in a house with standard loop-in wiring to
each light fitting, and had to put junction boxes in the ceiling to
nicely accommodate several new light fittings with only LNE terminals.

Thoughts?

Cheers,
David.

My lighting is (will be) all wall fittings or lighting outlet sockets.
(fortunately my wall fittings are large enough to change the terminal
block inside for something with more ways).

I'm doing loop-in to *most* of them, with 3-core droppers to the
switches (for the same reasons you suggest).

But I will have to do some loop through connections in back boxes -
I'm planning to use single crimps with heatshrink sleeving.

When I rewired a house for home automation, I ran all the switch
and lighting point wires back to central connection points (actually
consumer unit shells, because the DIN rail made it easy to mount
X10 dimmers and relays). It's easy to change the way things are
switched, rather like a Cat5 wiring closet,

Cool!

On 02/06/2010 11:11, Andrew Gabriel wrote:
When I rewired a house for home automation, I ran all the switch
and lighting point wires back to central connection points (actually
consumer unit shells, because the DIN rail made it easy to mount
X10 dimmers and relays). It's easy to change the way things are
switched, rather like a Cat5 wiring closet, and (important point
for selling) it's easy to strip out the home automation control
and revert to manual operation.

How would you handle multiway switching in such a scheme?

On 02/06/10 12:26, Jim wrote:
On 02/06/2010 11:11, Andrew Gabriel wrote:
When I rewired a house for home automation, I ran all the switch
and lighting point wires back to central connection points (actually
consumer unit shells, because the DIN rail made it easy to mount
X10 dimmers and relays). It's easy to change the way things are
switched, rather like a Cat5 wiring closet, and (important point
for selling) it's easy to strip out the home automation control
and revert to manual operation.

How would you handle multiway switching in such a scheme?

Multiple X10 senders (switch) for one address (light)?

--
Tim Watts

Hung parliament? Rather have a hanged parliament.

On Jun 2, 10:54*am, NT wrote:
On Jun 2, 10:36*am, David Robinson
wrote:

I fear I'm over thinking it, but any way of wiring a lighting circuit
seems to come with disadvantages...

1. standard UK loop-in power at each light fitting
advantages: standard, have unswitched power available at fitting for
future e.g. ceiling fan/light etc

Fan feed is a fairly big point imho, I'd look to include unswitched
live at the ceiling lighting points whatever scheme is used.

disadvantages: many modern light fittings don't have enough terminals,
or much space to add them

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

If you did it would suffer one of the 2 downsides of the Carter
system, which was outlawed in the 1930s. Ie that a switch failure is
liable to short out the supply, its a fire risk.

3. junction boxes in the ceiling
advantages: single wire to each light fitting and each switch
disadvantages: junction boxes are supposed to be accessible, but most
won't be in practice.

With a tool they could be, ie by unscrewing the light fitting first.
Also one can solder inside the jbox, fit the wires in the screw
connectors as normal, but leaving long tails, and solder those. The
screw cons then provide mechanical restraint for the solder joints.

won't have unswitched power anywhere except
junction box

you can have it anywhere you want by using an extra cable core.

4. wire singles: neutral looped into fittings, live looped into
switches
advantages: saves copper! fewer wires in general
disadvantages: induction loop interference, can you still buy cheap
singles, won't have unswitched power anywhere

again you get L, swL and N anywhere you want by fitting the necessary
singles to provide it.

5. any other options?

well, yes ... I doubt its what you'd want though.

6. mix and match the above as convenient
advantages: ?
disadvantages: confusing. will probably end up without unswitched
power where I need it!

I know in the past I lived in a house with standard loop-in wiring to
each light fitting, and had to put junction boxes in the ceiling to
nicely accommodate several new light fittings with only LNE terminals.

Thoughts?

Cheers,
David.

NT


Couple more options:

Mains to the light fittings, with the cable to lightswitch being cat5,
run on 12v with a relay
- you can then use anything at all for the switches, which much opens
up the decorative possibilities
- you can also add no end of extra switch ways later if desired

A ring circuit for lighting gives increased safety and reliability.

Its sometimes worth adding extra cable cores, so that later there is
the option to add a greater number of switch ways, enabling easy
switching between differing lighting levels.


NT

In article ,
Jim writes:
On 02/06/2010 11:11, Andrew Gabriel wrote:
When I rewired a house for home automation, I ran all the switch
and lighting point wires back to central connection points (actually
consumer unit shells, because the DIN rail made it easy to mount
X10 dimmers and relays). It's easy to change the way things are
switched, rather like a Cat5 wiring closet, and (important point
for selling) it's easy to strip out the home automation control
and revert to manual operation.

How would you handle multiway switching in such a scheme?

With home automation, all the switches are momentary action
anyway, so I simply wire multiple switches to one of the computer
inputs.

If I strip out the home automation, I can fit impulse relays
in the consumer unit shell and continue to drive with the
existing momentary action switches.

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

Thanks for all the answers...

On 2 June, 11:15, Tim Watts wrote:
On 02/06/10 10:36, David Robinson wrote:

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless it
says so) which would result in a rather noticeable bang followed by no
lights.

Special thanks to you Tim and also to NT for pointing out problems
with this!

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

Fine upstairs (JBs grouped in loft) but _really_ painful for
downstairs lights.

Downstairs I think I'll just loop into switches, join neutrals using a
chocolate block (one bit of!), and go from switch to fitting with 3-
core + earth to allow me to send unswitched live to fitting later if I
need to.

Shall I leave the initially unused strand of 3-core "floating" (I'm
worried about it touching something live and causing problems), or
parallel it to the switched live both ends, or wire it into the earth
both ends to keep it out of harm's way?

Cheers,
David.

"David Robinson" wrote in message
...
Thanks for all the answers...

On 2 June, 11:15, Tim Watts wrote:
On 02/06/10 10:36, David Robinson wrote:

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless it
says so) which would result in a rather noticeable bang followed by no
lights.

Special thanks to you Tim and also to NT for pointing out problems
with this!

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

Fine upstairs (JBs grouped in loft) but _really_ painful for
downstairs lights.

Downstairs I think I'll just loop into switches, join neutrals using a
chocolate block (one bit of!), and go from switch to fitting with 3-
core + earth to allow me to send unswitched live to fitting later if I
need to.

Shall I leave the initially unused strand of 3-core "floating" (I'm
worried about it touching something live and causing problems), or
parallel it to the switched live both ends, or wire it into the earth
both ends to keep it out of harm's way?

Cheers,
David.

I usually earth spare cores.

Adam

In article ,
Andrew Gabriel wrote:
All switch drop cables are triple and earth, which allows either
to get a neutral to the switch or to add a second switch in the
future. Again, many of the lighting points are triple and earth,
for future flexibility.

Yup. Very useful if you decide to add table lights etc switched from the
same place at a later date.

--
*Who are these kids and why are they calling me Mom?

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

"David Robinson" wrote in message
...
Thanks for all the answers...

On 2 June, 11:15, Tim Watts wrote:
On 02/06/10 10:36, David Robinson wrote:

2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless it
says so) which would result in a rather noticeable bang followed by no
lights.

Special thanks to you Tim and also to NT for pointing out problems
with this!

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

Fine upstairs (JBs grouped in loft) but _really_ painful for
downstairs lights.

Downstairs I think I'll just loop into switches, join neutrals using a
chocolate block (one bit of!), and go from switch to fitting with 3-
core + earth to allow me to send unswitched live to fitting later if I
need to.

Shall I leave the initially unused strand of 3-core "floating" (I'm
worried about it touching something live and causing problems), or
parallel it to the switched live both ends, or wire it into the earth
both ends to keep it out of harm's way?

Cheers,
David.

I usually leave spare cores unstripped and put tape over each end, so it
looks spare, and not a possible replacement to a broken earth.

Toby...

On 2 June, 15:19, David Robinson
wrote:
Thanks for all the answers...

On 2 June, 11:15, Tim Watts wrote:

On 02/06/10 10:36, David Robinson wrote:
2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless it
says so) which would result in a rather noticeable bang followed by no
lights.

Special thanks to you Tim and also to NT for pointing out problems
with this!

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

Fine upstairs (JBs grouped in loft) but _really_ painful for
downstairs lights.

Downstairs I think I'll just loop into switches, join neutrals using a
chocolate block (one bit of!), and go from switch to fitting with 3-
core + earth to allow me to send unswitched live to fitting later if I
need to.

Hang on a second - with standard 3-core + earth (brown, black, grey),
I don't have a blue for neutral.

I'm sure I've used 3-core before with one of those colours carrying
neutral (interlinked smoke alarms being the most obvious; brown =
live, black = neutral, grey - interlink I think) - but where in the
regs does it say that this is allowed?

Specifically, the on-site guide says neutral = blue, and that's it.

Brown obviously works for live, and black and grey obviously work for
switched live - but black or grey for neutral - where does it say I
can do that?!

Cheers,
David.

"David Robinson" wrote in message
...
On 2 June, 15:19, David Robinson
wrote:
Thanks for all the answers...

On 2 June, 11:15, Tim Watts wrote:

On 02/06/10 10:36, David Robinson wrote:
2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless
it
says so) which would result in a rather noticeable bang followed by no
lights.

Special thanks to you Tim and also to NT for pointing out problems
with this!

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

Fine upstairs (JBs grouped in loft) but _really_ painful for
downstairs lights.

Downstairs I think I'll just loop into switches, join neutrals using a
chocolate block (one bit of!), and go from switch to fitting with 3-
core + earth to allow me to send unswitched live to fitting later if I
need to.

Hang on a second - with standard 3-core + earth (brown, black, grey),
I don't have a blue for neutral.

I'm sure I've used 3-core before with one of those colours carrying
neutral (interlinked smoke alarms being the most obvious; brown =
live, black = neutral, grey - interlink I think) - but where in the
regs does it say that this is allowed?

Specifically, the on-site guide says neutral = blue, and that's it.

Brown obviously works for live, and black and grey obviously work for
switched live - but black or grey for neutral - where does it say I
can do that?!

Cheers,
David.

You need some blue sleeving.

Good practice is to sleeve the grey not the black with blue sleeving and use
that as the neutral connection where needed.

Adam

On 02/06/10 18:19, David Robinson wrote:
On 2 June, 15:19, David
wrote:
Thanks for all the answers...

On 2 June, 11:15, Tim wrote:

On 02/06/10 10:36, David Robinson wrote:
2. loop-in power at each switch
advantages: single wire to each light fitting, have unswitched power
available at fitting for future e.g. timer, neon etc
disadvantages: lots of wires to each switch, need extra terminals
behind each switch
(question: can I use the "unused" terminal of a 2-way switch to join
the neutrals, so that when the switch is "off" the two wires going to
the light fitting are shorted?)

No! There's no guarantee that the switch is break-before-make (unless it
says so) which would result in a rather noticeable bang followed by no
lights.

Special thanks to you Tim and also to NT for pointing out problems
with this!

5. any other options?

JBs in a more remote but accessible location? Eg group them in a few
locations and have little access panels in the floor. More cable
required, but easier to maintain.

Fine upstairs (JBs grouped in loft) but _really_ painful for
downstairs lights.

Downstairs I think I'll just loop into switches, join neutrals using a
chocolate block (one bit of!), and go from switch to fitting with 3-
core + earth to allow me to send unswitched live to fitting later if I
need to.

Hang on a second - with standard 3-core + earth (brown, black, grey),
I don't have a blue for neutral.

I'm sure I've used 3-core before with one of those colours carrying
neutral (interlinked smoke alarms being the most obvious; brown =
live, black = neutral, grey - interlink I think) - but where in the
regs does it say that this is allowed?

Specifically, the on-site guide says neutral = blue, and that's it.

Brown obviously works for live, and black and grey obviously work for
switched live - but black or grey for neutral - where does it say I
can do that?!

Cheers,
David.

You sleeve it blue. All the regs are concerned with is that "live"
(meaning live and neutral) conductors are suitably insulated and
protected and that the are identifiable at the ends. The only conductor
that must not be abused is the CPC/earth. You cannot use a green/yellow
marked conductor, nor the bare conductor in T+E cable for any purpose
other than the earth (identification and the fact that the CPC in T+E is
only protected by the sheath and is also usually undersized).

You can use an otherwised marked conductor as a CPC though provided it
is marked (cf using one of the conductors in SWA as well as the armour
to transport the circuit CPC (and possibly bonding or earthing conductor
- the roles are different although a single conductor may combine more
than one role).

--
Tim Watts

Hung parliament? Rather have a hanged parliament.

"David Robinson" wrote in message
...

5. any other options?

All lights on a radial with electronic control at the fittings X10 being the
most common but not the best.
Switches are cordless.

In article ,
"dennis@home" writes:


"David Robinson" wrote in message
...

5. any other options?

All lights on a radial with electronic control at the fittings X10 being the
most common but not the best.
Switches are cordless.

X10 spread this way is common when retrofitting home automation,
but if you're rewiring anyway, I would question it.

Although I mentioned X10 before, very little of my home automation
is done with X10 - actually for main lighting, only one room, and
that's because I wanted a dimmer. Other than that, I use DIN mounted
relays - much cheaper (and more reliable than X10).

I do have some other bits of X10 - tends to get used when I put
something new onto home automation, before I get around to providing
what I regard as the more permanent solution (relay switching).

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

On 2 June, 18:27, "ARWadsworth"
wrote:
"David Robinson" wrote in message

Hang on a second - with standard 3-core + earth (brown, black, grey),
I don't have a blue for neutral.

I'm sure I've used 3-core before with one of those colours carrying
neutral (interlinked smoke alarms being the most obvious; brown =
live, black = neutral, grey - interlink I think) - but where in the
regs does it say that this is allowed?

Specifically, the on-site guide says neutral = blue, and that's it.

Brown obviously works for live, and black and grey obviously work for
switched live - but black or grey for neutral - where does it say I
can do that?!

You need some blue sleeving.

OK - will just swapping the last 1-2cm of the insulation for blue
insulation (stripped from a blue wire elsewhere) do? That's what I've
done in the past to mark the blue as brown in a switch feed (but back
then, no one was checking!).

Good practice is to sleeve the grey not the black with blue sleeving and use
that as the neutral connection where needed.

Why grey not black? (Just interested).

I was going to use brown for the switched live - but then thought "if/
when I want both switched and unswitched live down this cable, brown
will definately be unswitched live, so grey (or following your advice,
black) will be switched".

Pity there's no proper guide on the use of 3-core colours in various
scenarios, including this one. Am I correct in believing this means it
doesn't actually matter?

Cheers,
David.

On 02/06/10 21:11, David Robinson wrote:
On 2 June, 18:27,
wrote:
"David wrote in message

Hang on a second - with standard 3-core + earth (brown, black, grey),
I don't have a blue for neutral.

I'm sure I've used 3-core before with one of those colours carrying
neutral (interlinked smoke alarms being the most obvious; brown =
live, black = neutral, grey - interlink I think) - but where in the
regs does it say that this is allowed?

Specifically, the on-site guide says neutral = blue, and that's it.

Brown obviously works for live, and black and grey obviously work for
switched live - but black or grey for neutral - where does it say I
can do that?!

You need some blue sleeving.

OK - will just swapping the last 1-2cm of the insulation for blue
insulation (stripped from a blue wire elsewhere) do? That's what I've
done in the past to mark the blue as brown in a switch feed (but back
then, no one was checking!).

Heavens no. You'll have a broken point in the insulation. You can use
blue insulating tape (B&Q) instead of sleeve.

Good practice is to sleeve the grey not the black with blue sleeving and use
that as the neutral connection where needed.

Why grey not black? (Just interested).

Trying to break the association that black is neutral - or that's the
story I heard.

I was going to use brown for the switched live - but then thought "if/
when I want both switched and unswitched live down this cable, brown
will definately be unswitched live, so grey (or following your advice,
black) will be switched".

Pity there's no proper guide on the use of 3-core colours in various
scenarios, including this one. Am I correct in believing this means it
doesn't actually matter?

--
Tim Watts

Hung parliament? Rather have a hanged parliament.

On 2 June, 23:41, Tim Watts wrote:
On 02/06/10 21:11, David Robinson wrote:

OK - will just swapping the last 1-2cm of the insulation for blue
insulation (stripped from a blue wire elsewhere) do? That's what I've
done in the past to mark the blue as brown in a switch feed (but back
then, no one was checking!).

Heavens no. You'll have a broken point in the insulation. You can use
blue insulating tape (B&Q) instead of sleeve.

Good point. Though it was more like 0.5cm, so was almost in the switch
terminal anyway. I don't like insulation tape, but I agree it's safer
in this context.

Good practice is to sleeve the grey not the black with blue sleeving and use
that as the neutral connection where needed.

Why grey not black? (Just interested).

Trying to break the association that black is neutral - or that's the
story I heard.

Interesting. That's quite funny really - in the old colours, I used
the Blue of 3-core for the Neutral on the smoke alarms precisely
because it was neutral in the "other"(at the time, flex only) colours.

(I hate these new colours - but I know I'm 5 years too late to say
it!)

Neutral Grey it is then.

Thanks for all your help.

Cheers,
David.

In article
,
David Robinson wrote:
Trying to break the association that black is neutral - or that's the
story I heard.

Interesting. That's quite funny really - in the old colours, I used
the Blue of 3-core for the Neutral on the smoke alarms precisely
because it was neutral in the "other"(at the time, flex only) colours.

But the three phase colours predated the change in flex colours by many
many years.

(I hate these new colours - but I know I'm 5 years too late to say
it!)

It should have been done years ago when the flex colours changed - you'd
have been used to it by now. ;-)

Neutral Grey it is then.

Thanks for all your help.

Cheers,
David.

--
*Letting a cat out of the bag is easier than putting it back in *

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

On 3 June, 09:58, "Dave Plowman (News)" wrote:
In article
,
* *David Robinson wrote:

(I hate these new colours - but I know I'm 5 years too late to say
it!)

It should have been done years ago when the flex colours changed - you'd
have been used to it by now. ;-)

Nah - they'd still be lousy colours for being able to tell apart in
the dirt/dust/dark!

Cheers,
David.

In article
,
David Robinson wrote:
On 3 June, 09:58, "Dave Plowman (News)" wrote:
In article
,
David Robinson wrote:

(I hate these new colours - but I know I'm 5 years too late to say
it!)

It should have been done years ago when the flex colours changed -
you'd have been used to it by now. ;-)

Nah - they'd still be lousy colours for being able to tell apart in
the dirt/dust/dark!

That was one of the main reasons for changing from red lack and green as
flex colours - a large proportion of the male population can't tell red
and green apart, especially in poor light. Green/yellow should be
identifiable to those with poor colour vision.

--
*And don't start a sentence with a conjunction *

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