I've been helping a friend sort out some of the electric's in their
house.

They are at the stage of installing a new CU, bringing all the earth
bonding up to scratch and then sorting out the main earth connection.

They are installing the new CU in a new location to a bit to get more
space (to the other side of the wall from the meter and current
fusebox).

Main earth bonding to the incoming gas and water services is being
renewed, but we weren't sure where to terminate this - run it back to
the CU or install some sort of earth terminal near the meter and then
run the bonding cables, and the earth from the CU back to there. The
latter makes more sense to me, but I can't see it really matters.

Re the earth connection, currently the installation has been earthed
via the lead mains water pipe, once the works are done, he intends to
get the earth connection made properly by the supply co. The supply
presumably dates back to the late 1930's when the house was built and
that the earth would likely be TN-S (underground supply, in town).

Does he just make all his connections, then contact supply co. to come
and make the final earth connection?
--
Chris French, Leeds

Main earth bonding to the incoming gas and water services is being
renewed, but we weren't sure where to terminate this - run it back to
the CU or install some sort of earth terminal near the meter and then
run the bonding cables, and the earth from the CU back to there. The
latter makes more sense to me, but I can't see it really matters.

I'd use a separate earth block near the incoming cut out.

Does he just make all his connections, then contact supply co. to come
and make the final earth connection?

Yes, provided the supply company has agreed to provide one. Otherwise, it is
earth rod and 100mA time delay RCD time.

Christian.

Christian McArdle wrote:
Main earth bonding to the incoming gas and water services is being
renewed, but we weren't sure where to terminate this - run it back to
the CU or install some sort of earth terminal near the meter and then
run the bonding cables, and the earth from the CU back to there. The
latter makes more sense to me, but I can't see it really matters.

I'd use a separate earth block near the incoming cut out.

The Regs/OSG have a firm opinion - a Main Earthing Terminal outside the
CU is strongly preferred, if not mandated: it allows for better testing
and inspection, and I guess makes it marginally less likely that the
main bonding conductors will be disturbed during add-n-move work in the
CU/dis-board. One more practicality consideration is that the terminals
on externally-mounted earth blocks (widely available in 5-way and 8-way
sizes, from memory) is that each Hole is big enough for a 10mmsq
conductor at least, more usually a 16mmsq (the outer ones at least are
sized for 16mmsq+).

As for putting the main earthing terminal close to CU or close to
incoming supply - I don't think there's an overriding argument (or reg)
either way: practical factors such as proximity of the other services
you're bonding to will usually make one or other preferred in those
rarish cases where incoming supply and CU aren't within a couple of
metres of each other...

Stefek

In message , Christian
McArdle writes
Does he just make all his connections, then contact supply co. to come
and make the final earth connection?

Yes, provided the supply company has agreed to provide one. Otherwise, it is
earth rod and 100mA time delay RCD time.

He had one go a while back, but couldn't get them to talk any sense.

He explained (or tried to) what he was planning on doing, and any
specific requirements etc. from them, but all the person he spoke to
could do was witter on about getting an electrician in, that the
electric's in the house were nothing to do with them. I don't think they
really understood what he as talking about.

--
Chris French, Leeds

In message ,
Stefek Zaba wrote:

The Regs/OSG have a firm opinion - a Main Earthing Terminal outside the
CU is strongly preferred, if not mandated:

See 542-04-02, I don't see this as in any way mandating an external
terminal, though having one would often make this requirement easier to
fulfil.

The biggest problem I have when doing this is the mandatory "Safety
Electrical Connection" label - I'm probably missing a trick, but the
only source of these I have at the moment is to nick them from pipe
clamps which then leaves me with a pile of unuseable clamps.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... Don't worry, I'm fluent in weirdo...

In message ,
chris French wrote:

In message , Christian
McArdle writes
Does he just make all his connections, then contact supply co. to come
and make the final earth connection?

Yes, provided the supply company has agreed to provide one. Otherwise, it is
earth rod and 100mA time delay RCD time.

He had one go a while back, but couldn't get them to talk any sense.

He explained (or tried to) what he was planning on doing, and any
specific requirements etc. from them, but all the person he spoke to
could do was witter on about getting an electrician in, that the
electric's in the house were nothing to do with them. I don't think they
really understood what he as talking about.


You need to find out who the actual supplier is - i.e. the people
responsible for the infrastructure in the area, not the people he pays
the bill to. Around here (South Wales) it is Western Power Distribution
and their number is in the phone book. In Derby it used to be East
Midlands Electricity and their number is still in the phonebook (use the
"new supplies" one) but the actual company involved is something else
altogether now - a name I've forgotten.

Western Power will often provide a PME terminal for free, if the local
supply is capable. The people who have just done this for me in Derby
wanted forms filling in and a fee of £75.

I suppose what I'm saying is that it is a case of finding the right
people to speak to.

HTH

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... I'm dangerous when I know what I'm doing.

Main earth bonding to the incoming gas and water services is being
renewed, but we weren't sure where to terminate this - run it back to
the CU or install some sort of earth terminal near the meter and then
run the bonding cables, and the earth from the CU back to there. The
latter makes more sense to me, but I can't see it really matters.

I'd use a separate earth block near the incoming cut out.

The Regs/OSG have a firm opinion - a Main Earthing Terminal outside the
CU is strongly preferred, if not mandated: it allows for better testing
and inspection, and I guess makes it marginally less likely that the
main bonding conductors will be disturbed during add-n-move work in the
CU/dis-board. One more practicality consideration is that the terminals
on externally-mounted earth blocks (widely available in 5-way and 8-way
sizes, from memory) is that each Hole is big enough for a 10mmsq
conductor at least, more usually a 16mmsq (the outer ones at least are
sized for 16mmsq+).

I am about to replace my CU (well have been getting round to it for a few
weeks now!) - if you have an earth block outside the CU does this
effectively go between the incoming earth and the earth rail in the CU (i.e.
wire main incomer - earth block, earth block - CU, earth block - gas
main, earth block - water main etc)?

I am about to replace my CU (well have been getting round to it for a few
weeks now!) - if you have an earth block outside the CU does this
effectively go between the incoming earth and the earth rail in the CU
(i.e.
wire main incomer - earth block, earth block - CU, earth block - gas
main, earth block - water main etc)?

Yes. All main equipotential bonding, incoming earths and the consumer unit
earths are connected here. If doing the lot from scratch, ensure you install
to TN-C-S (PME) specs, even if you don't have PME available. Otherwise, when
the electricity company upgrades you, you're shafted.

Christian.

In message , Martin Angove
writes
In message ,
chris French wrote:

In message , Christian
McArdle writes
Does he just make all his connections, then contact supply co. to come
and make the final earth connection?

Yes, provided the supply company has agreed to provide one. Otherwise, it is
earth rod and 100mA time delay RCD time.

He had one go a while back, but couldn't get them to talk any sense.


You need to find out who the actual supplier is - i.e. the people
responsible for the infrastructure in the area, not the people he pays
the bill to.

Yep, we realised that- it'd Yorkshire Electricity (or whatever they are
called now)


I suppose what I'm saying is that it is a case of finding the right
people to speak to.

Yes, that's the conclusion we came too. I think the person he spoke to
didn't quite understand what was being asked, and instead of admitting
such and passing us on, tried to give an answer they thought was right
--
Chris French, Leeds

I'm in exactly the same situation (in Leeds) - but am one step further on as
I have installed the new CU and bonding etc.

I contacted British Gas (my electricity supplier) who - eventually -
understood that I needed a proper earth system and agreed (verbally) that it
was their responsibility and they would do it for free. At one point they
even described it as "an electrical emergency" - which was putting it a
little melodramatically.

Anyway, they sent someone out to sort it out (this was before I had the
consumer unit and bonding done) and they looked at it and said "there's
nothing I can do - there's nothing to attach the new earth to". Fair point,
I suppose, as I hadn't got an earth block at that point and they weren't
going to provide me with one. So I waited until I'd done it myself, and then
got them back out again. (Incidentally, it's Meter Plus who they send to do
their work).

This time, they said "can't do anything for you - you've got an old knockout
[I think that's his terminology] and that needs replacing before I can do
anything. Anyway, I wouldn't do it for my pay 'cause they expect you to work
on the system live". Fair point again, but I still don't have an earth. He
said he'd pass on the request for the new "knockout" to be installed,
estimated 7-8 weeks. Then, he'll send someone else to do the earth.

So, it seems they will do it, but as for when, your guess is as good as
mine.

Tom

"Martin Angove" wrote in message
...
In message ,
chris French wrote:

In message , Christian
McArdle writes
Does he just make all his connections, then contact supply co. to
come
and make the final earth connection?

Yes, provided the supply company has agreed to provide one. Otherwise,
it is
earth rod and 100mA time delay RCD time.

He had one go a while back, but couldn't get them to talk any sense.

He explained (or tried to) what he was planning on doing, and any
specific requirements etc. from them, but all the person he spoke to
could do was witter on about getting an electrician in, that the
electric's in the house were nothing to do with them. I don't think they
really understood what he as talking about.


You need to find out who the actual supplier is - i.e. the people
responsible for the infrastructure in the area, not the people he pays
the bill to. Around here (South Wales) it is Western Power Distribution
and their number is in the phone book. In Derby it used to be East
Midlands Electricity and their number is still in the phonebook (use the
"new supplies" one) but the actual company involved is something else
altogether now - a name I've forgotten.

Western Power will often provide a PME terminal for free, if the local
supply is capable. The people who have just done this for me in Derby
wanted forms filling in and a fee of £75.

I suppose what I'm saying is that it is a case of finding the right
people to speak to.

HTH

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
... I'm dangerous when I know what I'm doing.

In article ,
Martin Angove wrote:
The biggest problem I have when doing this is the mandatory "Safety
Electrical Connection" label - I'm probably missing a trick, but the
only source of these I have at the moment is to nick them from pipe
clamps which then leaves me with a pile of unuseable clamps.


I've always thought the label on an earth clamp rather strange - what
other purpose would a clamp on a pipe with a cable coming from it serve?

--
*Bills travel through the mail at twice the speed of cheques *

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

"Tom W" wrote
| I contacted British Gas (my electricity supplier) who - eventually -
| understood that I needed a proper earth system and agreed (verbally)
| that it was their responsibility

Which it isn't. The electricity supplier is not required to provide you with
an earth

| This time, they said "can't do anything for you - you've got an old
| knockout [I think that's his terminology]

Would that be a "cutout" (service fuse assembly)?

| and that needs replacing before I can do anything. Anyway, I wouldn't
| do it for my pay 'cause they expect you to work on the system live".
| Fair point again,

Well, if he doesn't like the job there's always McDonalds. And he shouldn't
be live working unless he has been specifically trained.

Owain

"Dave Plowman (News)" wrote
| Martin Angove wrote:
| The biggest problem I have when doing this is the mandatory
| "Safety Electrical Connection" label - I'm probably missing
| a trick, but the only source of these I have at the moment
| is to nick them from pipe clamps which then leaves me with
| a pile of unuseable clamps.

Sell them on fetishgear.com as a form of body jewellery?

| I've always thought the label on an earth clamp rather strange
| - what other purpose would a clamp on a pipe with a cable coming
| from it serve?

Differentiate between safety electrical earth and a functional earth for
telecomms or grandma's wireless?

Owain

Dave Plowman (News) wrote:

I've always thought the label on an earth clamp rather strange - what
other purpose would a clamp on a pipe with a cable coming from it serve?

It's mandated by BS 951 which goes back to 1948, if not before.
Plumbers in those days...

--
Andy

"Andy Wade" wrote
| Dave Plowman (News) wrote:
| I've always thought the label on an earth clamp rather strange
| - what other purpose would a clamp on a pipe with a cable coming
| from it serve?
| It's mandated by BS 951 which goes back to 1948, if not before.

Probably to indicate the (bare copper) earth wasn't anything to do with the
wireless, then.

| Plumbers in those days...

Were plentiful, available, honest and cheap?

Owain

In message , Christian
McArdle writes
I am about to replace my CU (well have been getting round to it for a few
weeks now!) - if you have an earth block outside the CU does this
effectively go between the incoming earth and the earth rail in the CU
(i.e.
wire main incomer - earth block, earth block - CU, earth block - gas
main, earth block - water main etc)?

Yes. All main equipotential bonding, incoming earths and the consumer unit
earths are connected here. If doing the lot from scratch, ensure you install
to TN-C-S (PME) specs, even if you don't have PME available. Otherwise, when
the electricity company upgrades you, you're shafted.


Oh go on, save me the effort of looking it up :-) what does that mean in
practice?
--
Chris French, Leeds

Oh go on, save me the effort of looking it up :-) what does that mean in
practice?

Using meaty earth cable. The OSG states the size of earthing conductors for
each type of earthing. Always install those recommended for TN-C-S, whatever
type of earthing you actually have.

Christian.

Martin Angove wrote in message ...

You need to find out who the actual supplier is - i.e. the people
responsible for the infrastructure in the area, not the people he pays
the bill to. Around here (South Wales) it is Western Power Distribution
and their number is in the phone book. In Derby it used to be East
Midlands Electricity and their number is still in the phonebook (use the
"new supplies" one) but the actual company involved is something else
altogether now - a name I've forgotten.

This is certainly drifting off on a tangent, but I believe that East
Midlands Electricity is now Powergen.

How do I know this?

Five-ish years ago I was working in Stafford, and East Midlands
Electricity ran an advert on the TV to promote the change of name.
I'll never forget that advert, it went something like this:

- Fade up to show a close-up of an old chap screwing in a light bulb.
- Zoom out to show him screwing in the next light bulb in a large
grid; and the next bulb; and the next..
- Pan to show the sky in the background. The sky goes dark, then
light, then dark, then light. A few days pass, and this poor chap
still hasn't finished fitting these light bulbs.
- Finally there is a shot of the last light bulb to be fitted. The
light bulbs are turned on and the chap leans back with a contented
sigh.
- Zoom out to show his completed effort. It's a large matrix display
of lamps on top of a large building (presumably their headquarters),
and it reads "EAST MIDLANDS ELECTRICITY"

- Cut to voice-over and caption, saying:
"East Midlands Electricity . . . is now changing its name to Powergen"

- Cut to old man, sighing, starting to unscrew all the light bulbs...!
:-)


At the time I remember thinking it was a superb advert. I wonder if
anybody has kept a copy on video somewhere? It surely deserves to be
preserved for posterity!

Cheers,

Jonathan

In message ,
(Jonathan) wrote:


This is certainly drifting off on a tangent, but I believe that East
Midlands Electricity is now Powergen.


Nah, they're something else. One of those wishy-washy,
doesn't-sound-like-an-electricity-company names. But when I looked it up
in the phonebook it was there under EME.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... Hackers do it with bugs.

In message ,
chris French wrote:

In message , Martin Angove
writes
In message ,
chris French wrote:

In message , Christian
McArdle writes
Does he just make all his connections, then contact supply co. to come
and make the final earth connection?

Yes, provided the supply company has agreed to provide one. Otherwise, it is
earth rod and 100mA time delay RCD time.

He had one go a while back, but couldn't get them to talk any sense.


You need to find out who the actual supplier is - i.e. the people
responsible for the infrastructure in the area, not the people he pays
the bill to.

Yep, we realised that- it'd Yorkshire Electricity (or whatever they are
called now)


I suppose what I'm saying is that it is a case of finding the right
people to speak to.

Yes, that's the conclusion we came too. I think the person he spoke to
didn't quite understand what was being asked, and instead of admitting
such and passing us on, tried to give an answer they thought was right

In Derby I needed specifically to telephone the "New Supplies" number in
the phonebook. Does YE have a similar number? If not, try bandying the
phrases "PME", "TN-C-S" or "TN-S" around. Sometimes jargon like this
rings a bell in what passes for the brain of the telephone answerer and
causes them to remember some long-past training they undertook.

HTH.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... Please Tell Me if you Don't Get This Message

In message ,
"Tom W" wrote:

I'm in exactly the same situation (in Leeds) - but am one step further on as
I have installed the new CU and bonding etc.

I contacted British Gas (my electricity supplier)
[...]

Anyway, they sent someone out to sort it out (this was before I had the
consumer unit and bonding done) and they looked at it and said "there's
nothing I can do - there's nothing to attach the new earth to". Fair point,
I suppose, as I hadn't got an earth block at that point and they weren't
going to provide me with one.

That's interesting. Down here with Western Power they *won't* attach
your earth. Instead they attach a short "tail" to the cutout and put a
chunky black box on the end with chunky terminals in it. There's room in
there for (if you need it) three additional cables of up to 25mm2 (I'm
guessing there, but 16mm2 is a very easy fit). In other words, it
matters not whether you've already done the rest of the work, PME can be
"made available" for you to use when you're ready.

Up in Derby, they connected my dangling G&Y without bother.

Of course, for PME they have to do the external loop impedance test
first - if the reading is too high they physically can't give you an
earth and you'll have to make other arrangements.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... "Bother", said Pooh, as received his telephone bill