David Robinson explained :
I always have, because I've always seen it done, but I wondered about
this when reading...
http://www.esc.org.uk/pdfs/business-...ry/BPG4_08.pdf

On page 15 (bottom right) it says that not earthing a metallic back
box is a code 4 ("not up to current regs") only if the back box
doesn't have a fixed lug that comes into contact with an earthed
eyelet on the accessory.

Is a socket an "accessory"? Does the fixing screw count as making
contact between the eyelet and the box?

If so, I can't see why people bother with running an earth wire to the
back box (all the sockets I've ever bought connect the earth to the
eyelet) so why is this common practice? Have I misunderstood the
above, or is this covered elsewhere in the regs?

(Obviously you have to earth a light switch back box, because there's
no earth on a switch - this is specifically about sockets)

The idea is to ensure both socket and both are properly earthed, even
when the screws are taken out and the accessory hanging on its wires.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

I always have, because I've always seen it done, but I wondered about
this when reading...
http://www.esc.org.uk/pdfs/business-...ry/BPG4_08.pdf

On page 15 (bottom right) it says that not earthing a metallic back
box is a code 4 ("not up to current regs") only if the back box
doesn't have a fixed lug that comes into contact with an earthed
eyelet on the accessory.

Is a socket an "accessory"? Does the fixing screw count as making
contact between the eyelet and the box?

If so, I can't see why people bother with running an earth wire to the
back box (all the sockets I've ever bought connect the earth to the
eyelet) so why is this common practice? Have I misunderstood the
above, or is this covered elsewhere in the regs?

(Obviously you have to earth a light switch back box, because there's
no earth on a switch - this is specifically about sockets)

Cheers,
David.

David Robinson :
I always have, because I've always seen it done, but I wondered about
this when reading...
http://www.esc.org.uk/pdfs/business-...ty/electrical-
industry/BPG4_08.pdf

On page 15 (bottom right) it says that not earthing a metallic back
box is a code 4 ("not up to current regs") only if the back box
doesn't have a fixed lug that comes into contact with an earthed
eyelet on the accessory.

I'm no expert but my understanding is...

Is a socket an "accessory"?

Yes.

Does the fixing screw count as making
contact between the eyelet and the box?

Yes but eyelets aren't generally earthed so that doesn't count.

--
Mike Barnes

On Nov 22, 5:02*pm, Mike Barnes wrote:
David Robinson :

I always have, because I've always seen it done, but I wondered about
this when reading...
http://www.esc.org.uk/pdfs/business-...ty/electrical-
industry/BPG4_08.pdf

On page 15 (bottom right) it says that not earthing a metallic back
box is a code 4 ("not up to current regs") only if the back box
doesn't have a fixed lug that comes into contact with an earthed
eyelet on the accessory.

I'm no expert but my understanding is...

Is a socket an "accessory"?

Yes.

Does the fixing screw count as making
contact between the eyelet and the box?

Yes but eyelets aren't generally earthed so that doesn't count.

--
Mike Barnes

I think the eyelets are earthed. Some of the earth terminals on
boxes nowadays look extremely dodgy to me. Sort of folded metal
instead of the brass thing we used to get.

In article
,
David Robinson wrote:
Is a socket an "accessory"? Does the fixing screw count as making
contact between the eyelet and the box?

No. Not enough pressure for a reliable contact.

--
*Reality? Is that where the pizza delivery guy comes from?

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

David Robinson wrote:
I always have, because I've always seen it done, but I wondered about
this when reading...
http://www.esc.org.uk/pdfs/business-...ry/BPG4_08.pdf

On page 15 (bottom right) it says that not earthing a metallic back
box is a code 4 ("not up to current regs") only if the back box
doesn't have a fixed lug that comes into contact with an earthed
eyelet on the accessory.

Is a socket an "accessory"? Does the fixing screw count as making
contact between the eyelet and the box?

Yes the fixing screw makes the earth between the eyelet and the backbox if
it is a fixed lug.

If so, I can't see why people bother with running an earth wire to the
back box (all the sockets I've ever bought connect the earth to the
eyelet) so why is this common practice? Have I misunderstood the
above, or is this covered elsewhere in the regs?

People like to make too much work for themselves or follow old regs (such as
bonding a kitchen sink)

--
Adam

On Nov 22, 6:20*pm, "Dave Plowman (News)"
wrote:

No. Not enough pressure for a reliable contact.

The sockets in our 2007 new-build house are all wired like that i.e.
no seperate earth to the back box, only that obtained via the fixing
screw to the earthed socket wiring plate. I would be surprised if this
wiring was non regs-compliant.

It is my understanding that if the back box has at least one fixed
lug, and the socket earth is present at both screw positions (they
usually are these days), then this is perfectly acceptable.

Mathew

Mathew Newton wrote:
On Nov 22, 6:20 pm, "Dave Plowman (News)"
wrote:

No. Not enough pressure for a reliable contact.

The sockets in our 2007 new-build house are all wired like that i.e.
no seperate earth to the back box, only that obtained via the fixing
screw to the earthed socket wiring plate. I would be surprised if this
wiring was non regs-compliant.

It is my understanding that if the back box has at least one fixed
lug, and the socket earth is present at both screw positions (they
usually are these days), then this is perfectly acceptable.


Have a read of

http://www.gtectraining.co.uk/images/back%20boxes.pdf


--
Adam

On Nov 22, 7:52*pm, "ARWadsworth"
wrote:

Have a read of

http://www.gtectraining.co.uk/images/back%20boxes.pdf

Thanks Adam - a useful reference.

Mathew

In article ,
ARWadsworth wrote:
Is a socket an "accessory"? Does the fixing screw count as making
contact between the eyelet and the box?

Yes the fixing screw makes the earth between the eyelet and the backbox
if it is a fixed lug.

Do all boxes have one fixed lug these days? My favourites had both
adjustable.

If so, I can't see why people bother with running an earth wire to the
back box (all the sockets I've ever bought connect the earth to the
eyelet) so why is this common practice? Have I misunderstood the
above, or is this covered elsewhere in the regs?

People like to make too much work for themselves or follow old regs
(such as bonding a kitchen sink)

I've always fitted this extra earth wire. And grommets. ;-)

--
*El nino made me do it

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

Dave Plowman (News) wrote:
In article ,
ARWadsworth wrote:
Is a socket an "accessory"? Does the fixing screw count as making
contact between the eyelet and the box?

Yes the fixing screw makes the earth between the eyelet and the
backbox if it is a fixed lug.

Do all boxes have one fixed lug these days? My favourites had both
adjustable.

That is so 1960's.

If so, I can't see why people bother with running an earth wire to
the back box (all the sockets I've ever bought connect the earth to
the eyelet) so why is this common practice? Have I misunderstood the
above, or is this covered elsewhere in the regs?

People like to make too much work for themselves or follow old regs
(such as bonding a kitchen sink)

I've always fitted this extra earth wire. And grommets. ;-)

Next you will bragging about fitting earth sleeving to the cpc:-)

Not fitting the earth tail is allowed (a minimum standard). That does not
stop a good DIYer fitting the earth lead if they feel happier doing so.

--
Adam

In article ,
ARWadsworth wrote:
Do all boxes have one fixed lug these days? My favourites had both
adjustable.

That is so 1960's.

Yup. To go with a '60s spirit level. A proper sparks one - if it read
wrong just turn it round...

If so, I can't see why people bother with running an earth wire to
the back box (all the sockets I've ever bought connect the earth to
the eyelet) so why is this common practice? Have I misunderstood the
above, or is this covered elsewhere in the regs?

People like to make too much work for themselves or follow old regs
(such as bonding a kitchen sink)

I've always fitted this extra earth wire. And grommets. ;-)

Next you will bragging about fitting earth sleeving to the cpc:-)

Not fitting the earth tail is allowed (a minimum standard). That does
not stop a good DIYer fitting the earth lead if they feel happier doing
so.

I can understand someone fitting thousands for a living keeping things as
simple and fast as possible.

--
*OK, so what's the speed of dark? *

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

On Nov 22, 4:50*pm, David Robinson
wrote:

If so, I can't see why people bother with running an earth wire to the
back box (all the sockets I've ever bought connect the earth to the
eyelet) so why is this common practice?

What do the regs say about Metalclad sockets mounted on a surface,
particularly where a row of them are joined together with conduit
nipples. Obviously one has to be earthed with a tail, as do the
sockets themselves, but do all the back boxes have to be tailed
individually, or is their interconnection through the conduit nipples
seen as adequate?

On 23/11/2010 02:11, Andy Dingley wrote:
he regs say about Metalclad sockets mounted on a surface,
particularly where a row of them are joined together with conduit
nipples. Obviously one has to be earthed with a tail, as do the
sockets themselves, but do all the back boxes have to be tailed
individually, or is their interconnection through the conduit nipples
seen as adequate?

If metal conduit is acting as the CPC it would be sufficient, regs-wise,
simply to have a tail between the earth terminal of each box and its
socket. Good workmanship is of course required to ensure earth
continuity between the boxes, as for the rest of the conduit system.

If the primary CPC is a wire in the conduit the regs don't have anything
specific to say, other that all exposed-conductive-parts must be
earthed, including the conduit itself. I would daisy chain the CPC
between the socket earth terminals (as for L & N) and add a separate
box-earthing tail in each box.

--
Andy

On Nov 22, 10:16*pm, Mathew Newton wrote:
On Nov 22, 7:52*pm, "ARWadsworth"
wrote:

Have a read of

http://www.gtectraining.co.uk/images/back%20boxes.pdf

Thanks Adam - a useful reference.

+1.

I might add some anyway where the plasterer has gunked the eyelets up,
but otherwise this has put my mind at rest.

Cheers,
David.