I'm doing some renovating work an old house at the mo, and have turned my
attention to the electrics... Today I've been endeavouring to check the
various earth cables and bonding arrangements. I've found two old green
6mm(?) earth lead which emerge from the plaster adjacent to the (ancient)
fusebox and connect to a terminal block, from which I'd expect to find at
least one wire heading for the fusebox, and another heading for the house
earth, whatever that is. But as far as I can see(*), nothing; so presumably
there's no earthing in the house at all. All I can find is a small,
uninsulated, twisted wire dangling down from the terminal block, with an eye
in one end, which once upon a time will have been connected somewhere I
suppose.

This lot clearly needs some work to sort out; but I am confused about what
earthing provision there _should_ be. I've read the FAQ again, but am not
clear how I find out what sort of earthing system I have, or should have.
Is it up to the electric co to provide one, ie can I whinge at them? Or do
I need to fit an earthing rod? If so, where do you put them - this is a
solid floor house, and the front (which is where the meters are) is directly
on to the pavement.

Thanks for any pointers.

David


*It's incredibly difficult to see anything; some knobhead has installed the
gas meter directly in front of the electric meter and board (presumably too
close for regs); and then somebody else, equally cerebrally-challenged, has
built a large fitted cupboard enclosing the whole lot, in the corner of the
room. Best I can do is point my digital camera round the back of the gas
meter and then examine the pictures!

Best I can do is point my digital camera round the back of the gas
meter and then examine the pictures!

If you would...

Christian.

In message ,
"Christian McArdle" wrote:

Best I can do is point my digital camera round the back of the gas
meter and then examine the pictures!

If you would...


In case that was too obscure, what Christian is saying is that it would
help us enormously if you could take a few shots of the installation (an
overview and one or two closeups perhaps), stick them up on a website
somewhere and then post the link in this thread.

As you say, sounds like you have an interesting situation and need to
get sorted.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... I believe I will take this opportunity to remove my ears.

"Martin Angove" wrote in message
...
In message ,
"Christian McArdle" wrote:

Best I can do is point my digital camera round the back of the gas
meter and then examine the pictures!

If you would...


In case that was too obscure, what Christian is saying is that it would
help us enormously if you could take a few shots of the installation (an
overview and one or two closeups perhaps), stick them up on a website
somewhere and then post the link in this thread.

Yup, I realised! OK, after a protracted session of Noddy does HTML, please
have a look at http://tinyurl.com/67ggt where I've done my best. Any advice
appreciated (and I don't mean 'rip it out and start again'; I think that
goes without saying! It's the earthing question I'm most concerned about.)

Thanks a lot
David

"Lobster" wrote in message
...
"Martin Angove" wrote in message
...
In message ,
"Christian McArdle" wrote:

Best I can do is point my digital camera round the back of the gas
meter and then examine the pictures!

If you would...


In case that was too obscure, what Christian is saying is that it would
help us enormously if you could take a few shots of the installation (an
overview and one or two closeups perhaps), stick them up on a website
somewhere and then post the link in this thread.

Yup, I realised! OK, after a protracted session of Noddy does HTML,
please
have a look at http://tinyurl.com/67ggt where I've done my best. Any
advice
appreciated (and I don't mean 'rip it out and start again'; I think that
goes without saying! It's the earthing question I'm most concerned
about.)

Thanks a lot
David



WOW WEEEEEE !!!!!! Rip it out and start again mate!!! If you have an
electrical fire at the consumer unit (God Forbid), or a lightning strike to
the power supply outside, you won't know anything about it. It would be
over for you by the time you got out your seat.

You now need at least a 10mm sq' Green / Yellow sleeved conductor from the
consumer side of both the water and gas supplies, and that means even over
the short distances you have between the gas and electrical service in the
cupboard. These two leads can be connected to a separate block beside the
consumer unit and then one other lead directly from the block to your
consumer unit earthing bar.

You'll also need a sixteen millimetre (16mm) sq' Green / Yellow from the
earthing bar of the consumer unit to the main supply cable of the electrical
service headend, which is under the black main fuse block, and properly
clamped to the outer braiding of the supply cable.

For one thing, the electrical supply should be at a minimum of 500mm spacing
away from any gas supply equipment, and vice versa of course. Next, the gas
and electrical supplies should be fully accessible in case of emergency.

The last thing to have been installed inside that cupboard was the gas
meter, and it sure weren't fitted by a CORGI engineer. The soldering gives
that show away, unless that is, the engineer was going in blind like you had
to with the camera.

By the look of it you'll have to, and I mean have to, move either the gas
meter or the electrics to one side of the cupboard, and leave the other
service supply at the other side. This looks to be the only way you're
going to get the 500mm spacing between them in the area you've got to work
in.

Rip it out and start again mate. For your own safety.

"BigWallop" wrote in message
...

"Lobster" wrote in message
...

Yup, I realised! OK, after a protracted session of Noddy does HTML,
please
have a look at http://tinyurl.com/67ggt where I've done my best. Any
advice
appreciated (and I don't mean 'rip it out and start again'; I think that
goes without saying! It's the earthing question I'm most concerned
about.)

WOW WEEEEEE !!!!!! Rip it out and start again mate!!! If you have an
electrical fire at the consumer unit (God Forbid), or a lightning strike
to
the power supply outside, you won't know anything about it. It would be
over for you by the time you got out your seat.

Yeah, cool isn't it! Have no fear, 'rip out' is definitely the plan...!

You'll also need a sixteen millimetre (16mm) sq' Green / Yellow from the
earthing bar of the consumer unit to the main supply cable of the
electrical
service headend, which is under the black main fuse block, and properly
clamped to the outer braiding of the supply cable.

This bit was really the reason for my post, cos I'm not clear about the main
'supply' earth. The other issues I'm Ok with. So I take it that it's
possible to confirm that mine is definitely a TN-S system (he says, having
just looked at the FAQ again!)? If I scrape away the black crap which seems
to cover the electrical service headend, I should find braid there, then?
(As you'll appreciate, this is well-nigh impossible to get at to even check,
right now).

By the look of it you'll have to, and I mean have to, move either the gas
meter or the electrics to one side of the cupboard, and leave the other
service supply at the other side. This looks to be the only way you're
going to get the 500mm spacing between them in the area you've got to work
in.

Yes, fortunately the cupboard is L-shaped (goes round the corner to the
right), so it will be quite easy to get the gas meter moved round there.

Thanks for the reply
David

"Lobster" wrote
| Yup, I realised! OK, after a protracted session of Noddy does
| HTML,

www.irfanview.com will produce an HTML gallery of thumbnails with links to
your original images. For linux, try mkgallery

| please have a look at http://tinyurl.com/67ggt

a.k.a.
http://www.angelfire.com/falcon/eric...rcupboard.html

| where I've done my best. Any advice appreciated (and I don't
| mean 'rip it out and start again'; I think that goes without
| saying! It's the earthing question I'm most concerned about.)

I'd worry more about the gas than the electrics. I've seen better soldering
by blind heroin addicts.

Owain

In article ,
Owain wrote:
I'd worry more about the gas than the electrics. I've seen better
soldering by blind heroin addicts.

Not too neat, is it?. But could still be perfectly safe.

--
*Is it true that cannibals don't eat clowns because they taste funny?

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

"Lobster" wrote
| ... I've found two old green 6mm(?) earth lead which emerge from the
| plaster adjacent to the (ancient) fusebox and connect to a terminal
| block,

Those might disappear off to water and gas pipes somewhere.

| from which I'd expect to find at least one wire heading for
| the fusebox, and another heading for the house earth, whatever that
| is. But as far as I can see(*), nothing; so presumably there's no
| earthing in the house at all. All I can find is a small, uninsulated,
| twisted wire dangling down from the terminal block, with an eye
| in one end, which once upon a time will have been connected somewhere
| I suppose.

to the fusebox, especially if it is (or an even older one was) metalclad.

It is also possible that there's an earth (ie bonding) from a socket in the
kitchen to the cold water main, and that, brought back through the circuit
protective conductor to the fusebox, was considered sufficient to earth the
whole installation.

Owain

"Owain" wrote in message
...
"Lobster" wrote
| ... I've found two old green 6mm(?) earth lead which emerge from the
| plaster adjacent to the (ancient) fusebox and connect to a terminal
| block,

Those might disappear off to water and gas pipes somewhere.

Indeed; one such lead is in fact attached to CW piping below the kitchen
sink (which is close to the water main, located at the opposite end of the
house) but I haven't confirmed continuity to one of those near the fusebox
yet.

It is also possible that there's an earth (ie bonding) from a socket in
the
kitchen to the cold water main, and that, brought back through the circuit
protective conductor to the fusebox, was considered sufficient to earth
the
whole installation.

Yes that does fit the evidence! If so, I suppose the place is marginally
less of a death trap than I thought, but either way, it will be sorted.

Thanks
David

On 4 Nov 2004 "Lobster" wrote:

"Owain" wrote:
"Lobster" wrote
| ... I've found two old green 6mm(?) earth lead which emerge from
| the plaster adjacent to the (ancient) fusebox and connect to a
| terminal block,

Those might disappear off to water and gas pipes somewhere.

Indeed; one such lead is in fact attached to CW piping below the
kitchen sink (which is close to the water main, located at the
opposite end of the house) but I haven't confirmed continuity to one
of those near the fusebox yet.

It is also possible that there's an earth (ie bonding) from a socket
in the kitchen to the cold water main, and that, brought back through
the circuit protective conductor to the fusebox, was considered
sufficient to earth the whole installation.

Yes that does fit the evidence! If so, I suppose the place is marginally
less of a death trap than I thought, but either way, it will be sorted.

It used to be common practice to bond the house earth to the rising
water main. However with water companies increasingly using plastic
piping this is no longer reliable. It's now necessary to bond the
house's water system to an independent earth.

--
Richard Porter
Mail to username ricp at domain minijem.plus.com
"You can't have Windows without pains."

"Owain" wrote in message ...
"Lobster" wrote
| ... I've found two old green 6mm(?) earth lead which emerge from the
| plaster adjacent to the (ancient) fusebox and connect to a terminal
| block,

Those might disappear off to water and gas pipes somewhere.

or they might be disconnected, who knows. Have seen that one before.


It is also possible that there's an earth (ie bonding) from a socket in the
kitchen to the cold water main, and that, brought back through the circuit
protective conductor to the fusebox, was considered sufficient to earth the
whole installation.


You say the house has been rewired recently, but to be honest thats
hard to believe from the pics of the fusebox. Partial rewiring might
have been done, but the idea that someone managed to gain enough
access to that old fusebox is stretching it. And again, if they didnt
replace an old and inaccessible 4-way wire fuse only box, or even
upgrade it to mcbs, youve got to wonder what they were thinking.

Does the bathroom have equipotential bonding? Is there an electric
shower? Electric cooker? Is there an earth wire running down the side
of the house exterior?

Clearly youve got to start again, at least in the CU area, but before
doing that youve got to get access. I dont know whats going on with
the cupboard but you'll have to make at the minimum another access
door so you can actually get to things, both to do the work, and for
future householder access.

If I knew who'd done the gas job I'd be calling them back to refit it
sensibly at no further cost. On second thoughts..... maybe not!

If it were mine I might start by checking resistance from house wiring
earth to real earth, as it would at least give a very quick idea of
how unsatisfactory things are. If R is high you would have a high risk
install there. If R is nice and low that would at least be reassuring
on that fairly major point.

I also would check and test all existing circuits, with a setup like
that I wouldnt want to make assumptions.


NT

"N. Thornton" wrote in message
om...

You say the house has been rewired recently, but to be honest thats
hard to believe from the pics of the fusebox. Partial rewiring might
have been done, but the idea that someone managed to gain enough
access to that old fusebox is stretching it. And again, if they didnt
replace an old and inaccessible 4-way wire fuse only box, or even
upgrade it to mcbs, youve got to wonder what they were thinking.

You may be right - I can't remember (or find!) what I said about rewiring,
but it certainly wouldn't have been that
recent; I just meant that it was more recent than the fusebox suggests. I
would certainly
guess that the gas meter was added later though.

I certainly have lots of checking to do; I agree.

If it were mine I might start by checking resistance from house wiring
earth to real earth, as it would at least give a very quick idea of
how unsatisfactory things are. If R is high you would have a high risk
install there. If R is nice and low that would at least be reassuring
on that fairly major point.

What do you define as 'real earth' - are you refering to the incoming cable
sheath? Or an earth rod somewhere (which would be difficult as there's no
'soft' ground anywhere nearby.

Thanks
David

"Lobster" wrote in message ...
"N. Thornton" wrote in message
om...

You say the house has been rewired recently, but to be honest thats
hard to believe from the pics of the fusebox. Partial rewiring might
have been done, but the idea that someone managed to gain enough
access to that old fusebox is stretching it. And again, if they didnt
replace an old and inaccessible 4-way wire fuse only box, or even
upgrade it to mcbs, youve got to wonder what they were thinking.

You may be right - I can't remember (or find!) what I said about rewiring,
but it certainly wouldn't have been that
recent; I just meant that it was more recent than the fusebox suggests.

4 way Wylexes are typical 70s kit, and were widely installed in the
80s as well. Those old Wylexes arent as old as they first appear. In
the 70s they were partly wooden, and many people have misjudged their
age.

I
would certainly
guess that the gas meter was added later though.

ha, I hope so! If the leccy were added _sfter_ the gas there would be
more reason to worry


I certainly have lots of checking to do; I agree.

If it were mine I might start by checking resistance from house wiring
earth to real earth, as it would at least give a very quick idea of
how unsatisfactory things are. If R is high you would have a high risk
install there. If R is nice and low that would at least be reassuring
on that fairly major point.

What do you define as 'real earth' - are you refering to the incoming cable
sheath? Or an earth rod somewhere (which would be difficult as there's no
'soft' ground anywhere nearby.

Local earth rod, which you probably have in the form of an incoming
metal water mains pipe. Confirming low R doesnt mean all is well, but
it at least would eliminate the biggest possible risk of all, the lack
of any functional earth.

Unfortunately having an earth connection doesnt automatically imply it
will work as a safety feature. If earth R is too high, with no RCD the
fuse wires would sit there forever more before anything blows, with
the whole earth circuit live - but its not very likely to be anything
like that bad.


NT

Lobster wrote:

What do you define as 'real earth' - are you refering to the incoming cable
sheath? Or an earth rod somewhere (which would be difficult as there's no
'soft' ground anywhere nearby.

From the photos it looks as if there _might_ be an earth connection
made to the sheath of the supply cable - i.e. a TN-S earth. Now that
the gas meter is out of the way can you post a photo showing the supply
head - basically the same as 2.jpg but without the gas meter.

Other points:

- there appears no main bonding conductor to the gas service. Add this
once the Corgi man has done his bit. It needs to be 10mm^2 and goes
between the gas pipe on your side of the meter and the main earth
terminal; ditto for water if main bonding is missing;

- clean everything up;

- replace the fuse cover on the Wylex CU.

--
Andy