I'm doing up a house that I own at the moment after a tenant left it
in a less than perfect condition at the conclusion of a long-term let.

He's managed to rip a light switch clean off the wall. The switch is
for two wall up-lighters and the original wiring was a mess when I
found it.

Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard. Anyway, two of the cables go to the first light (the
terminal block behind the light has two live wires and two neutral
wires going into it.) The second (furthest away) light only has one
live and one neutral cable going to it.

I bought a new light switch. It's the only switch for the lights and
the terminals on the switch are marked L1, L2 and Common.

I think that I need to put the feed live (from the mains) into the
Common terminal. I think I then put the live wires from the other two
cables into the L1 terminal on the switch and connect the neutral
wires together in a terminal block so that they are unbroken from the
mains. Is this correct? How do I know which live cable should go to
Common as there is no black sheathed cable - only three brown cables
to choose from?

I know that I should call an electrician etc. but the nearest sparky
is 100 miles away and this should really be a simple job. Any advice
on what to do would be much appreciated.

Evan Brown wrote:
Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

That's the new standard, though I keep having to stop
myself calling them blue and red.

How do I know which live cable should go to
Common as there is no black sheathed cable - only three brown cables
to choose from?

What I would do - as an experienced electrician, and I'm
not recommending you do this unless you know you can
do it safely and competently - is ensure the wires are
all electrically seperated (eg by connecting them to
seperate terminals of a 6-way connector block), turn the
power on, and then test between brown & blue on each
pair to find the incoming feed. Had to do that just a
couple of days ago to find which cables coming into
two pairs of sockets were the legs of the ring back to
the CU.

JGH

"jgharston" wrote in message
...
Evan Brown wrote:
Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

That's the new standard, though I keep having to stop
myself calling them blue and red.

How do I know which live cable should go to
Common as there is no black sheathed cable - only three brown cables
to choose from?

What I would do - as an experienced electrician, and I'm
not recommending you do this unless you know you can
do it safely and competently - is ensure the wires are
all electrically seperated (eg by connecting them to
seperate terminals of a 6-way connector block), turn the
power on, and then test between brown & blue on each
pair to find the incoming feed. Had to do that just a
couple of days ago to find which cables coming into
two pairs of sockets were the legs of the ring back to
the CU.

JGH

He should pay for a electrician.
All like take and no like pay.
I wonder if the gentleman is aware that may require fire protection in his
building?

On Mar 16, 7:46*pm, "Mr Pounder"
wrote:
"jgharston" wrote in message

...



Evan Brown wrote:
Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

That's the new standard, though I keep having to stop
myself calling them blue and red.

How do I know which live cable should go to
Common as there is no black sheathed cable - only three brown cables
to choose from?

What I would do - as an experienced electrician, and I'm
not recommending you do this unless you know you can
do it safely and competently - is ensure the wires are
all electrically seperated (eg by connecting them to
seperate terminals of a 6-way connector block), turn the
power on, and then test between brown & blue on each
pair to find the incoming feed. Had to do that just a
couple of days ago to find which cables coming into
two pairs of sockets were the legs of the ring back to
the CU.

JGH

He should pay for a electrician.
All like take and no like pay.
I wonder if the gentleman is aware that may require fire protection in his
building?



Ah, an archetypal Usenet moron replies. I take it you've lined up all
your paper clips and alphebetised your CD collection already and have
now run out of things to do. Why not go for a drive so that you can
give other road users the benefit of your unmatched experience and
skill through the illegal use of your horn?

There are no tradesmen within 100 miles of my property and last week I
paid a locksmith £327 just to replace two cylinder locks in a set of
French windows. £200 of that charge was for travel.

The wiring in the house has been in for fifteen years and was a self-
install job from the start - I know the guy who used to live in the
house and who did the work himself.

I'm not interested in your opinion unless it relates directly to the
substance of the question that I asked and I take any advice given
entirely at my own risk.

On 16/03/2011 18:42, Evan Brown wrote:
[...]

Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

Brown & blue ('harmonised colours') have been allowed since 2004 and
mandatory since 2006. The cables are, I hope, actually 3-core with the
earths sleeved green/yellow and connected together in the switch's back box.

I think that I need to put the feed live (from the mains) into the
Common terminal. I think I then put the live wires from the other two
cables into the L1 terminal on the switch and connect the neutral
wires together in a terminal block so that they are unbroken from the
mains. Is this correct?

Not quite, but it does sound as if you have the 'switch feed' type of
wiring. To help confirm so, check the following:

- this is a one-gang, one-way switch (one switch for the two lights, and
no other switch(es) control the same lights);

- at the light with two cables they are simply connected in parallel,
brown to brown and blue to blue - this will be an incoming switched
feed to the first light (from the switch) and an outgoing feed to the
second light;

- at the switch, the three blues are, or were, connected together with
an insulated terminal.

Assuming the above is the case the three cables at the switch will be an
incoming mains feed (brown line, blue neutral), an outgoing ditto to
another switch, and a switched feed for the lights.

You need to find which cable is the one that feeds the lights. Isolate
the circuit and turn off all other lights on it. Ensure that at least
one of the lights in question has an intact filament 'bulb' in it, not a
CFL. A continuity check with a multimeter on a resistance range will
then find the desired cable - you'll read the cold resistance of the
lamp(s). (Confirm by removing lamps, if necessary). The other two
cables will read open-circuit (or possibly a higher resistance if
there's a shaver transformer or similar on the circuit).

The connections required are then:

- 2 lines, incoming and outgoing feeds, to one side of the switch (COM
or L1);

- 1 line, identified as switched feed to lights in question, to other
side of switch (L1 or COM);

- 3 neutrals, connect together with a terminal block, ensure no bare
copper is showing, i.e. no risk of neutral-earth (or any other) shorts.

Restore power and test. If the switch works upside-down, swap L1
connection(s) to L2.

HTH
--
Andy

Evan Brown wrote:
On Mar 16, 7:46 pm, "Mr Pounder"
wrote:
"jgharston" wrote in message

...



Evan Brown wrote:
Currently I have three two-core cables at the switch - all are
colour coded blue and brown for neutral and live which I think is
non- standard.

That's the new standard, though I keep having to stop
myself calling them blue and red.

How do I know which live cable should go to
Common as there is no black sheathed cable - only three brown
cables to choose from?

What I would do - as an experienced electrician, and I'm
not recommending you do this unless you know you can
do it safely and competently - is ensure the wires are
all electrically seperated (eg by connecting them to
seperate terminals of a 6-way connector block), turn the
power on, and then test between brown & blue on each
pair to find the incoming feed. Had to do that just a
couple of days ago to find which cables coming into
two pairs of sockets were the legs of the ring back to
the CU.

JGH

He should pay for a electrician.
All like take and no like pay.
I wonder if the gentleman is aware that may require fire protection
in his building?



Ah, an archetypal Usenet moron replies. I take it you've lined up all
your paper clips and alphebetised your CD collection already and have
now run out of things to do. Why not go for a drive so that you can
give other road users the benefit of your unmatched experience and
skill through the illegal use of your horn?

There are no tradesmen within 100 miles of my property and last week I
paid a locksmith £327 just to replace two cylinder locks in a set of
French windows. £200 of that charge was for travel.

The wiring in the house has been in for fifteen years and was a self-
install job from the start - I know the guy who used to live in the
house and who did the work himself.

Odd colours for a 15 year old cable. Is it twin and earth cable or flex?

What test equipment do you have (multimeter etc)?

Cheers
--
Adam

In article a11ad630-45fd-4014-83be-
,
says...
I'm not interested in your opinion unless it relates directly to the
substance of the question that I asked and I take any advice given
entirely at my own risk.


Er - this is usenet - you'll get opinions of all shapes and flavours,
many unrelated to the original question and some tangential to the point
of obscurity. Unless you like being very frustrated, I'd get used to it,
if I were you.

As to the wiring...your best bet is to work it out from first principles
on a bit of paper. The fundamentals are that the flow (yeah, I know it's
AC) goes from the circuit breaker through the switch and the bulb to the
neutral. Sometimes the switch is before the bulb.

Since the chances of any self-installed wiring following a set colour
scheme are slim, it really is going to be down to chasing wires through
and making a few educated guesses which you then test to see which was
right.

--
Skipweasel - never knowingly understood.

John Rumm wrote:
Evan Brown wrote:
Currently I have three two-core cables at the switch
Anyway, two of the cables go to the first light
That does not seem quite right...

Yes, re-reading there's something odd there.
"I have three two-core cables at the switch"
"Two of the cables go to the first light"

I think I subconciosly edited that to "two of the
cables go to the lights, ie:

SUPPLY /
BRN -------o/ o--+-BRN----------------*
BLU ---------@--+-|-BLU----------------* LIGHT
| |
| +-BRN----------------*
+---BLU----------------* LIGHT

which my testing method would identify the supply, the two others
are the lights. Similar to:
I could understand one feed cable into the switch and two switched
outputs - one to each light. However you would only have one cable
terminating at each light.

However...
the terminal block behind the light has two live wires and two
neutral wires going into it.) The second (furthest away) light
only has one live and one neutral cable going to it.

That suggests this:

SUPPLY /
BRN ---+-o/ o----BRN--------------+--*
BLU -+-|---@------BLU------------+-|--* LIGHT
| | | |
| +--BRN---- TO NEXT | +--------------*
+----BLU---- CIRCUIT +----------------* LIGHT

ie, this:
I could also understand one into the switch and one out, with the out
feeding the first light, and that having a second cable to feed the
second. That would match what you see at the lights but not the switch.

Which needs John's more involved testing to identify the
switched light feed and the loop-out feed to the next
circuit.

JGH

On Mar 16, 6:42*pm, Evan Brown wrote:
I'm doing up a house that I own at the moment after a tenant left it
in a less than perfect condition at the conclusion of a long-term let.

He's managed to rip a light switch clean off the wall. The switch is
for two wall up-lighters and the original wiring was a mess when I
found it.

Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard. Anyway, two of the cables go to the first light (the
terminal block behind the light has two live wires and two neutral
wires going into it.) The second (furthest away) light only has one
live and one neutral cable going to it.

I bought a new light switch. It's the only switch for the lights and
the terminals on the switch are marked L1, L2 and Common.

I think that I need to put the feed live (from the mains) into the
Common terminal. I think I then put the live wires from the other two
cables into the L1 terminal on the switch and connect the neutral
wires together in a terminal block so that they are unbroken from the
mains. Is this correct? How do I know which live cable should go to
Common as there is no black sheathed cable - only three brown cables
to choose from?

I know that I should call an electrician etc. but the nearest sparky
is 100 miles away and this should really be a simple job. Any advice
on what to do would be much appreciated.


Something is wrong with this picture. At an absolute minimum, one of
the cables to the switch should have an earth wire.

Imho its necessary that you find out what's going on with the cables
before connecting them up. If you don't make the effort to determine
this,
- you're connecting up a circuit that you know is non-compliant with
wiring regulations
- a switch ripped of the wall is a good hint that when wired up it
didnt work, or possibly worse

What I would do: I'd expose the light fitting wiring and use a
multimeter to trace the wires to/from the lights. I'd then use the
multimeter to find out what's going on with the other cable/flex or 2.
Ideally you should then replace the feed with 3 core and wire it all
up.

Switches with common, L1 and L2 work as an ordinary on off switch when
you use common & L1. It dosent matter which terminal is which.

You need a multimeter, assuming you can do this without endangering
anyone.
http://wiki.diyfaq.org.uk/index.php?title=Multimeter


NT

"Mr Pounder" wrote in message
...

Evan Brown wrote:
Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

He should pay for a electrician.
All like take and no like pay.
I wonder if the gentleman is aware that may require fire protection in his
building?

Why?

A HMO might require fire-doors and such but this sounds an ordinary tenanted
property.

--
Bartc

Evan Brown wrote:

On Mar 16, 7:46*pm, "Mr Pounder"
wrote:
"jgharston" wrote in message

...



Evan Brown wrote:
Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

The wiring in the house has been in for fifteen years and was a self-
install job from the start - I know the guy who used to live in the
house and who did the work himself.

That can't be right - the brown/blue colour code for fixed wiring came
in between 2004 and 2006 (see
http://wiki.diyfaq.org.uk/index.php?...armo nisation )
so this wiring can't be more than 7 years old.

Mike

On Thu, 17 Mar 2011 17:56:14 -0500, Mike Humphrey
wrote:

Evan Brown wrote:

On Mar 16, 7:46*pm, "Mr Pounder"
wrote:
"jgharston" wrote in message

...



Evan Brown wrote:
Currently I have three two-core cables at the switch - all are colour
coded blue and brown for neutral and live which I think is non-
standard.

The wiring in the house has been in for fifteen years and was a self-
install job from the start - I know the guy who used to live in the
house and who did the work himself.

That can't be right - the brown/blue colour code for fixed wiring came
in between 2004 and 2006 (see
http://wiki.diyfaq.org.uk/index.php?...armo nisation )
so this wiring can't be more than 7 years old.

Unless this 'fixed' wiring is flex...

--