What is the correct marking procedure when one needs to extend wiring
in an existing old colours circuit with cable in harmonised colours?
I am fairly certain that I know the answers to these usage cases, but
can't find a specific reference describing it.

I think that these examples cover most usage cases of transitioning
wiring where both colour standards are in use.

AIUI, there should also be a label on the CU, warning that the
installation has both colour standards. Does anybody know who sells
these?


Example 1
=========

Addition of a spur to a socket in a ring final circuit where existing
wiring is in old colours.

Example 2
=========

Change of wiring in a lighting circuit. Existing circuit wiring (old
colours) loops in and then out of ceiling rose to the next ceiling
fitting. Wiring in two core T&E from ceiling rose to one way switch.
Switch is being located to a different position, so new cable length
from rose to switch.

Example 3
=========

As (2) but with two way switch so the switch cable is now three core
T&E (black/brown/grey).

Example 4
=========

As (2) or (3) but there is a a fan (bathroom) wired using three core T&E.


Questions
========

A) Should red and black wires from the existing old colour wiring be
sleeved in brown and blue at the fitting where the new wiring is being
added?

B) For examples (2) to (4) should the switched live (colour in cable,
blue), where it arrives back at the ceiling rose be sleeved in brown?

C) For examples (3) and (4) which colours in the section of cable
running from rose to the first two way switch? Presumably that is the
same as (B) if the cable is two core. What if it's three core? In
either case, at the first switch where it transitions anyway to three
core, how should each wire be sleeved?

D) For the section from the rose to the fan isolating switch and from
there to the fan, which cores for which purpose and sleeving colours
for each?

On Wed, 08 Nov 2006 07:31:08 +0000, Andy Hall wrote:


What is the correct marking procedure when one needs to extend wiring in
an existing old colours circuit with cable in harmonised colours? I am
fairly certain that I know the answers to these usage cases, but can't
find a specific reference describing it.

I think that these examples cover most usage cases of transitioning wiring
where both colour standards are in use.

AIUI, there should also be a label on the CU, warning that the
installation has both colour standards. Does anybody know who sells these?


Example 1
=========

Addition of a spur to a socket in a ring final circuit where existing
wiring is in old colours.

Example 2
=========

Change of wiring in a lighting circuit. Existing circuit wiring (old
colours) loops in and then out of ceiling rose to the next ceiling
fitting. Wiring in two core T&E from ceiling rose to one way switch.
Switch is being located to a different position, so new cable length
from rose to switch.

Example 3
=========

As (2) but with two way switch so the switch cable is now three core T&E
(black/brown/grey).

Example 4
=========

As (2) or (3) but there is a a fan (bathroom) wired using three core T&E.


Questions
========

A) Should red and black wires from the existing old colour wiring be
sleeved in brown and blue at the fitting where the new wiring is being
added?

B) For examples (2) to (4) should the switched live (colour in cable,
blue), where it arrives back at the ceiling rose be sleeved in brown?

C) For examples (3) and (4) which colours in the section of cable running
from rose to the first two way switch? Presumably that is the same as (B)
if the cable is two core. What if it's three core? In either case, at the
first switch where it transitions anyway to three core, how should each
wire be sleeved?

D) For the section from the rose to the fan isolating switch and from
there to the fan, which cores for which purpose and sleeving colours for
each?

===============================
Part answer - labels:

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

--
================================
Testing UBUNTU Linux
Everything working so far
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Andy Hall wrote:

What is the correct marking procedure when one needs to extend wiring in
an existing old colours circuit with cable in harmonised colours?

For a single phase installation there is no requirement for marking at
transitions.

AIUI, there should also be a label on the CU,

That is all that is required, except for sleeving cores in lighting
circuits, etc.

Does anybody know who sells these?

Any wholesaler - e.g.
http://www.tlc-direct.co.uk/Main_Ind...els/index.html

[Snip examples]

A) Should red and black wires from the existing old colour wiring be
sleeved in brown and blue at the fitting where the new wiring is being
added?

That's not a requirement, unless it's a 3-phase installation.

B) For examples (2) to (4) should the switched live (colour in cable,
blue), where it arrives back at the ceiling rose be sleeved in brown?

Yes. It should also be sleeved brown where it leaves the switch.

C) For examples (3) and (4) which colours in the section of cable
running from rose to the first two way switch? Presumably that is the
same as (B) if the cable is two core. What if it's three core? In
either case, at the first switch where it transitions anyway to three
core, how should each wire be sleeved?

The black and grey cores need to be sleeved brown at all points of
termination, since they are phase conductors. I would use the brown
core for the permanently 'live' side of the strappers, black for the
commons and grey for the second strapper (sw. L to light) - but that's
not standardised, AFAIK.

D) For the section from the rose to the fan isolating switch and from
there to the fan, which cores for which purpose and sleeving colours

Brown for phase, blue for neutral. The convention here is to use the
grey core (sleeved blue) for neutral, the idea being to dissociate the
colour black from being neutral. That leaves the brown core for
unswitched L and black (sleeved brown) for switched L.

HTH
--
Andy

On 2006-11-08 09:38:40 +0000, Andy Wade said:

Andy Hall wrote:

What is the correct marking procedure when one needs to extend wiring
in an existing old colours circuit with cable in harmonised colours?

For a single phase installation there is no requirement for marking at
transitions.

AIUI, there should also be a label on the CU,

That is all that is required, except for sleeving cores in lighting
circuits, etc.

Does anybody know who sells these?

Any wholesaler - e.g.
http://www.tlc-direct.co.uk/Main_Ind...els/index.html

[Snip

examples]

A) Should red and black wires from the existing old colour wiring be
sleeved in brown and blue at the fitting where the new wiring is being
added?

That's not a requirement, unless it's a 3-phase installation.

B) For examples (2) to (4) should the switched live (colour in cable,
blue), where it arrives back at the ceiling rose be sleeved in brown?

Yes. It should also be sleeved brown where it leaves the switch.

OK, makes sense - in other words, an unswitched or a switched live
marked in brown.



C) For examples (3) and (4) which colours in the section of cable
running from rose to the first two way switch? Presumably that is the
same as (B) if the cable is two core. What if it's three core? In
either case, at the first switch where it transitions anyway to three
core, how should each wire be sleeved?

The black and grey cores need to be sleeved brown at all points of
termination, since they are phase conductors. I would use the brown
core for the permanently 'live' side of the strappers, black for the
commons and grey for the second strapper (sw. L to light) - but that's
not standardised, AFAIK.

OK, but it makes sense.




D) For the section from the rose to the fan isolating switch and from
there to the fan, which cores for which purpose and sleeving colours

Brown for phase, blue for neutral. The convention here is to use the
grey core (sleeved blue) for neutral, the idea being to dissociate the
colour black from being neutral. That leaves the brown core for
unswitched L and black (sleeved brown) for switched L.

OK. That's clear enough.




HTH

Yes indeed, thanks.

Andy Hall wrote:

What is the correct marking procedure when one needs to extend wiring in
an existing old colours circuit with cable in harmonised colours?

I once asked the same question here and IIRC didn't get an answer - so I
won't claim this is necessarily correct procedure, but the strategy I've
adopted is basically to sleeve the individual wires with old- or
harmonised-coloured sleeving according to whether the individual wires
are themselves old or harmonised. So potentially mixing old and
harmonised sleeving within a fitting, if appropriate.

Only works as long as my stocks of red and black sleeving last, of course!

David