another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the upstairs
to get at the light wiring, as i wanted to change the switch layout in the
living rooms (was origionaly a normal bungalow, but when changed to a
dormer, the living room's light switch ended up behind where a corner sofa
naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living and
dining room lights were using the neuteral from the upstairs sockets, live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the wiring?
thinking about the RCD, but i'd have expected it to be tripping all the time
due to the neuteral from the lights going back down a rcd protected
neuteral, but it didnt and doesnt, works off the test button fine,

theres also a circuit in the breaker box that has me stumped, before the RCD
there's the 6 amp breaker for the lights (1950's bungalow, single lighting
ring for the entire house) and also a 16 amp breaker, this one feeds a spur,
but where it goes and what it does i don't know, any ideas to what would
want to be unprotected by an rcd that's not a lighting circuit??

the driveway flood light runs off the garage lighting circuit, the garage
has a breaker box which is run as a spur from a 32 amp breaker after the
rcd,
there an unused 32 amp rcd (was still connected up, but found the cable in
the floor upstairs taped up) that i've found out was for a lecky shower, but
again that was after the RCD as expected,

The kitchen only has 2 sockets in it, and they run from the ring main
breaker,
there's never been an electric cooker here, and 16 amps is too low for that,
no outbuildings or owt,

i just can't think what would want a 16 amp non rcd protected breaker,
the place has an alarm, but it's run from the ring main and hence is rcd
protected, combi boiler is powered by the ring main too.

gazz wrote:
another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the upstairs
to get at the light wiring, as i wanted to change the switch layout in the
living rooms (was origionaly a normal bungalow, but when changed to a
dormer, the living room's light switch ended up behind where a corner sofa
naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living and
dining room lights were using the neuteral from the upstairs sockets, live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the wiring?
thinking about the RCD, but i'd have expected it to be tripping all the time
due to the neuteral from the lights going back down a rcd protected
neuteral, but it didnt and doesnt, works off the test button fine,

if the 2 ccts feeeding the lighting are both run off the same rcd, the
rcd would behave. If not, it looks like you would have another
problem.



theres also a circuit in the breaker box that has me stumped, before the RCD
there's the 6 amp breaker for the lights (1950's bungalow, single lighting
ring for the entire house) and also a 16 amp breaker, this one feeds a spur,
but where it goes and what it does i don't know, any ideas to what would
want to be unprotected by an rcd that's not a lighting circuit??

immersion, outdoor feed, garage, etc. Just turn all except that one
off and see what you've still got running.


NT

wrote in message
...
gazz wrote:
another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the
upstairs
to get at the light wiring, as i wanted to change the switch layout in
the
living rooms (was origionaly a normal bungalow, but when changed to a
dormer, the living room's light switch ended up behind where a corner
sofa
naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living
and
dining room lights were using the neuteral from the upstairs sockets,
live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why
these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the
wiring?
thinking about the RCD, but i'd have expected it to be tripping all the
time
due to the neuteral from the lights going back down a rcd protected
neuteral, but it didnt and doesnt, works off the test button fine,

if the 2 ccts feeeding the lighting are both run off the same rcd, the
rcd would behave. If not, it looks like you would have another
problem.



theres also a circuit in the breaker box that has me stumped, before the
RCD
there's the 6 amp breaker for the lights (1950's bungalow, single
lighting
ring for the entire house) and also a 16 amp breaker, this one feeds a
spur,
but where it goes and what it does i don't know, any ideas to what would
want to be unprotected by an rcd that's not a lighting circuit??

immersion, outdoor feed, garage, etc. Just turn all except that one
off and see what you've still got running.


NT

Independent socket in the garage for a freezer maybe ? Sometimes prone to
nuisance tripping, and maybe some previous owner was away a lot ?

Arfa

"gazz" wrote in message
...
another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the
upstairs to get at the light wiring, as i wanted to change the switch
layout in the living rooms (was origionaly a normal bungalow, but when
changed to a dormer, the living room's light switch ended up behind where
a corner sofa naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living and
dining room lights were using the neuteral from the upstairs sockets, live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the
wiring? thinking about the RCD, but i'd have expected it to be tripping
all the time due to the neuteral from the lights going back down a rcd
protected neuteral, but it didnt and doesnt, works off the test button
fine,

I would expect it to trip too, are you sure the live to the lights doesn't
come off the ring too?

If it doesn't appear to and it still doesn't trip you have some other
obscure fault.

On 5 Aug, 09:49, "dennis@home" wrote:
"gazz" wrote in message

...



another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the
upstairs to get at the light wiring, as i wanted to change the switch
layout in the living rooms (was origionaly a normal bungalow, but when
changed to a dormer, the living room's light switch ended up behind where
a corner sofa naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living and
dining room lights were using the neuteral from the upstairs sockets, live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the
wiring? thinking about the RCD, but i'd have expected it to be tripping
all the time due to the neuteral from the lights going back down a rcd
protected neuteral, but it didnt and doesnt, works off the test button
fine,

I would expect it to trip too, are you sure the live to the lights doesn't
come off the ring too?

If it doesn't appear to and it still doesn't trip you have some other
obscure fault.

I would confirm that from experience. I regret to say that I did a
similar bodge many years ago when SWNBO started off saying she didn't
want a two way switch for a particular light and then changed her
mind !! And I stupidly didn't wire it to allow for the female mind,
and so had to borrow a neutral from 'somewhere else'.

When I changed the CU for a modern one recently, the RCD tripped every
time that light was switched on which was not unreasonable when the
'somewhere else' was the upstairs power ring, now protected by the
RCD. So a more acceptable re-wiring had to be undertaken.

The fact that your RCD is not tripping does suggest a further bit of
abomination somewhere.

By the way Gazz, the spelling is 'neutral' not 'neuteral' - that's as
bad as our George W and his 'noockalear' !

Rob

"robgraham" wrote in message
...
On 5 Aug, 09:49, "dennis@home" wrote:
"gazz" wrote in message

...



another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the
upstairs to get at the light wiring, as i wanted to change the switch
layout in the living rooms (was origionaly a normal bungalow, but when
changed to a dormer, the living room's light switch ended up behind
where
a corner sofa naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living
and
dining room lights were using the neuteral from the upstairs sockets,
live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why
these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the
wiring? thinking about the RCD, but i'd have expected it to be tripping
all the time due to the neuteral from the lights going back down a rcd
protected neuteral, but it didnt and doesnt, works off the test button
fine,

I would expect it to trip too, are you sure the live to the lights
doesn't
come off the ring too?

If it doesn't appear to and it still doesn't trip you have some other
obscure fault.

I would confirm that from experience. I regret to say that I did a
similar bodge many years ago when SWNBO started off saying she didn't
want a two way switch for a particular light and then changed her
mind !! And I stupidly didn't wire it to allow for the female mind,
and so had to borrow a neutral from 'somewhere else'.

When I changed the CU for a modern one recently, the RCD tripped every
time that light was switched on which was not unreasonable when the
'somewhere else' was the upstairs power ring, now protected by the
RCD. So a more acceptable re-wiring had to be undertaken.

The fact that your RCD is not tripping does suggest a further bit of
abomination somewhere.

By the way Gazz, the spelling is 'neutral' not 'neuteral' - that's as
bad as our George W and his 'noockalear' !

Rob

You shouldn't borrow a neutral. If you isolated the ring and broke the ring
and a light was switched on you would get a shock.

On Wed, 6 Aug 2008 00:03:34 +0100, "John"
wrote:

You shouldn't borrow a neutral. If you isolated the ring and broke the ring
and a light was switched on you would get a shock.

That's almost what happened to me a while ago working on some house
lighting in the studio of a theatre with which I'm involved. There
were two lots of lighting worked off two separate fuses in the same
switch-fuse. I was replacing one set of lighting, working by the light
of the other.
I'd pulled the fuse (obviously) of the lights I was working on. As I
disconnected one of the lamps I was suddenly plunged into darkness as
the others went out...I could've got a serious belt if I'd happened to
touch the neutral wire.
There's no excuse whatever for borrowing neutrals. All this was in
steel conduit. It would have been a doddle to provide proper neutrals.
The installation would have been some 10 - 15 years old at the time.

--
Frank Erskine

"Frank Erskine" wrote in message
...
On Wed, 6 Aug 2008 00:03:34 +0100, "John"
wrote:

You shouldn't borrow a neutral. If you isolated the ring and broke the
ring
and a light was switched on you would get a shock.

That's almost what happened to me a while ago working on some house
lighting in the studio of a theatre with which I'm involved. There
were two lots of lighting worked off two separate fuses in the same
switch-fuse. I was replacing one set of lighting, working by the light
of the other.
I'd pulled the fuse (obviously) of the lights I was working on. As I
disconnected one of the lamps I was suddenly plunged into darkness as
the others went out...I could've got a serious belt if I'd happened to
touch the neutral wire.
There's no excuse whatever for borrowing neutrals. All this was in
steel conduit. It would have been a doddle to provide proper neutrals.
The installation would have been some 10 - 15 years old at the time.

--
Frank Erskine

Thanks for confirming this Frank. I uncovered a situation at a my daughter's
house when I was decorating - I was curious to see why there was a plastered
over channel from a wall light to a plug socket. It turned out that the wall
lights got the live from a switch (converted from one gang to two gang) on
the lighting circuit and the neutral from the ring main. Whilst I was
concerned I hadn't fully appreciated to danger until I asked this group.

I now have a large warning label on the fuse box - until I get around to
getting a re-wire.

On Aug 5, 11:10*am, robgraham wrote:
On 5 Aug, 09:49, "dennis@home" wrote:





"gazz" wrote in message

...

another lectrical Q i'm afraid.

This time my bungalow, other day i took the floor boards up in the
upstairs to get at the light wiring, as i wanted to change the switch
layout in the living rooms (was origionaly a normal bungalow, but when
changed to a dormer, the living room's light switch ended up behind where
a corner sofa naturally goes due to a door being blocked up)

anyway, everywhere on the lighting circuit i found junctions (made from
uninsulated terminal block) at various socket cables neuterals, living and
dining room lights were using the neuteral from the upstairs sockets, live
fed via the lighting circuit, which still had a good neuteral but wasnt
used, so feck knows why it was wired like this,

i wired the 2 lights off a double switch 'properly' using the origional
neuterals in the lighting ring, and all works, so i have no idea why these
lights were on a borrowed neuteral from the ring main.

any idea's? and what implications does this have for the rest of the
wiring? thinking about the RCD, but i'd have expected it to be tripping
all the time due to the neuteral from the lights going back down a rcd
protected neuteral, but it didnt and doesnt, works off the test button
fine,

I would expect it to trip too, are you sure the live to the lights doesn't
come off the ring too?

If it doesn't appear to and it still doesn't trip you have some other
obscure fault.

I would confirm that from experience. *I regret to say that I did a
similar bodge many years ago when SWNBO started off saying she didn't
want a two way switch for a particular light and then changed her
mind !! *And I stupidly didn't wire it to allow for the female mind,
and so had to borrow a neutral from 'somewhere else'.

When I changed the CU for a modern one recently, the RCD tripped every
time that light was switched on which was not unreasonable when the
'somewhere else' was the upstairs power ring, now protected by the
RCD. *So a more acceptable re-wiring had to be undertaken.

The fact that your RCD is not tripping does suggest a further bit of
abomination somewhere.

By the way Gazz, the spelling is 'neutral' not 'neuteral' - that's as
bad as our George W and his 'noockalear' !


i think George W actually says "nucular" rather than 'noockalear';
he swaps two syllables rather than adding a new one.

Robert

is it OK to borrow an earth?

--

"George (dicegeorge)" wrote in message
...
is it OK to borrow an earth?

Not always.

George (dicegeorge) wrote:
is it OK to borrow an earth?

--
a whole one?

George (dicegeorge) wrote:

is it OK to borrow an earth?

Sometimes, but not usually. Every circuit must have a circuit
protective (earth) conductor, its CPC. One CPC can serve several
circuits although normal practice is to run a separate CPC for each
circuit, except where several circuits are run together in metal conduit
or trunking which serves as a common CPC for them all. The CPC for a
ring circuit must also be in the form of a ring, again unless metal
conduit is used.

Where an overcurrent device (fuse or MCB) is providing the earth fault
protection each CPC should follow the same route as the line and neutral
conductors, staying in close proximity to them. Effectively this
applies in all TN-earthed situations, even where RCDs are fitted for
additional protection.

In a TT installation, where RCDs provide the automatic disconnection of
earth faults, the close proximity requirement is removed, so I guess you
could say that borrowed earths here are OK. Don't forget though that
CPCs which aren't part of a cable and aren't protected in conduit or
trunking are subject to a minimum size of 4 mm^2 (as for supplementary
bonding) on grounds of mechanical robustness.

Unlike with neutrals, there's no objection to cross-connection occurring
between the CPCs of different circuits and this often happens in
practice where bathroom supplementary bonding links the power, lighting
and shower CPCs, or where two lighting circuits meet in one back box,
for example. Such cross-connection is generally beneficial since it
reduces earth fault loop impedance and can reduce the fault touch
voltage (like supplementary bonding).

HTH
--
Andy

aha, thanks Andy, so
CPC means circuit protective conductor...

An electrician said something about the existing grey cabling in this house
having a too thin earth wire-
(there are 2 fat wires going to 2 fuse wire boxes to feed distant rooms)
so should i take 4mm earth wire parallel to them and connect both ends,
or is there a better fatter earth wire to add-
as the cost of the wire is trivial compared to the cost of my time?

(I have a little mains tester plug with 3 red lights
and at one circuit there was no red light on the earth
so it was there that i borrowed an earth as a temporary solution)

--

[george]

~ [g] ~
~ ~
~ 07970 378 572 ~
~ www.dicegeorge.com ~
~ (c)2008 ~
~ ~


"Andy Wade" wrote in message
...
George (dicegeorge) wrote:

is it OK to borrow an earth?

Sometimes, but not usually. Every circuit must have a circuit protective
(earth) conductor, its CPC. One CPC can serve several circuits although
normal practice is to run a separate CPC for each circuit, except where
several circuits are run together in metal conduit or trunking which
serves as a common CPC for them all. The CPC for a ring circuit must also
be in the form of a ring, again unless metal conduit is used.

Where an overcurrent device (fuse or MCB) is providing the earth fault
protection each CPC should follow the same route as the line and neutral
conductors, staying in close proximity to them. Effectively this applies
in all TN-earthed situations, even where RCDs are fitted for additional
protection.

In a TT installation, where RCDs provide the automatic disconnection of
earth faults, the close proximity requirement is removed, so I guess you
could say that borrowed earths here are OK. Don't forget though that CPCs
which aren't part of a cable and aren't protected in conduit or trunking
are subject to a minimum size of 4 mm^2 (as for supplementary bonding) on
grounds of mechanical robustness.

Unlike with neutrals, there's no objection to cross-connection occurring
between the CPCs of different circuits and this often happens in practice
where bathroom supplementary bonding links the power, lighting and shower
CPCs, or where two lighting circuits meet in one back box, for example.
Such cross-connection is generally beneficial since it reduces earth fault
loop impedance and can reduce the fault touch voltage (like supplementary
bonding).

HTH
--
Andy