Plug socket replacement - not sure original socket is earthed correctly?

[robbo1987]

Hi all,

so one of my plug sockets has become faulty, the switch is stuck in the on position so i'm looking to replace the socket. the socket itself is white plastic but with a chrome screwless bezel over the front of it and i'll be looking to replace with something similar.

i've just switched everything off and just had a look behind the original socket before i buy a new one , and i've noticed that there is an earth cable, but there is no earth cable attached to the metal pattress box. should there be?

hopefully the attached pictures are clear enough, but basically when i replace the socket should i also be getting an extra length of earth wire from the earth point on the socket into the earthing point on the bottom left of the pattress box?

 

[mikehammer69]

There should be . It's a lazy method that uses the screws to earth the backbox

 

[EFLImpudence]

i've just switched everything off and just had a look behind the original socket before i buy a new one , and i've noticed that there is an earth cable, but there is no earth cable attached to the metal pattress box. should there be?

It's a good idea but not actually a requirement.

 

[Murdochcat]

There should be . It's a lazy method that uses the screws to earth the backbox

Not sure in agree with this

 

[endecotp]

Connecting the earth wires to the back box and relying on the screws to earth the socket is not allowed.

Connecting the earth wires to the socket and relying on the screws to earth the back box is allowed.

Connecting the earth wires to the socket and adding a wire to the back box earth terminal is belt-and-braces.

 

[pete01]

I always fit a fly lead I use 1.5mm green and yellow single.

 

[robbo1987]

Thanks all,

So in essence i can replace it with the wiring as is and that would be "ok" but best practice would be to just add an earth onto the back box.

Will just pick a bit of cable up in that case when i buy the new socket in that case.

 

[SUNRAY]

It's a good idea but not actually a requirement.

Connecting the earth wires to the back box and relying on the screws to earth the socket is not allowed.

Connecting the earth wires to the socket and relying on the screws to earth the back box is allowed.

Connecting the earth wires to the socket and adding a wire to the back box earth terminal is belt-and-braces.

I always fit a fly lead I use 1.5mm green and yellow single.

Thanks all,

So in essence i can replace it with the wiring as is and that would be "ok" but best practice would be to just add an earth onto the back box.

I always like to see the fly lead linking both too but as has been said - not essential

Will just pick a bit of cable up in that case when i buy the new socket in that case.

✔

 

[Risteard]

I always like to see the fly lead linking both too but as has been said - not essential

The superior National Rules for Electrical Installations in the south of Ireland actually do have an explicit requirement for it, and rightly so.

 

[FrodoOne]

The superior National Rules for Electrical Installations in the south of Ireland actually do have an explicit requirement for it, and rightly so.

The "superior" design of Socket-Outlets in Australia/New Zealand.
where there is no metal Yoke to be Earthed
and
no metal Box
means that there is no need (or ability) to connect the PE conductor to anything except the Earth terminals of the socket-outlet concerned.

(https://en.wikipedia.org/wiki/AS/NZS_3112#/media/File:Dual_3_Pin_Power_Outlet_-_Construction.jpg )

 

[ebee]

Not sure in agree with this

I am sure that I do agree with that! Having seen, for some reason a couple of times, the fixing screws for the socket have been replaced with nylon screws therefore no continuity from socket to backbox.
Although it might have been some event in the distant past to mitigate the lack of earths on lighting circuits there was no apparent evidence of such, it is not unknown for some people to have the small kernel of an idea to improve safety in one situation and then apply similar "improvements" in situations not appropriate. Some myths might get born that way.

Plus, sometimes such screws are deliberately slackened for say decorating, then not tightened, would you like to rely on such a connection one day?

 

[blup]

Using a fly lead offers protection when removing a socket face plate on an existing installation

 

[plugwash]

The "superior" design of Socket-Outlets in Australia/New Zealand

ROFLMAO

 

[endecotp]

sometimes such screws are deliberately slackened for say decorating, then not tightened, would you like to rely on such a connection one day?

Well, in what sense do you "rely on" the back box being earthed? I mean, what will happen if the back box loses its earth? It is (normally?) somewhat inaccessible, i.e. you can't (normally?) touch it, unlike e.g. the metal chassis of an appliance. And if you can poke your finger into a gap you might reach a live terminal before you get to the back box.

 

[ebee]

Well, in what sense do you "rely on" the back box being earthed? I mean, what will happen if the back box loses its earth? It is (normally?) somewhat inaccessible, i.e. you can't (normally?) touch it, unlike e.g. the metal chassis of an appliance. And if you can poke your finger into a gap you might reach a live terminal before you get to the back box.

Yes you are correct in that I agree but damp-ish plaster around a Live metal back box in the wall for one thing is a good idea to avoid as is access to a part of the box touchable by dry plaster being exposed as does happen in real life, both are shock risks.
A line conductor touching a back box that is solidly earthed is surely prefered to a "floating" (Electrically potential) is surely a better way to encourage automatic disconnection of supply during a fault.
Personally my own opinion but I would rather have the back boxes nicely earthed even below the touchable surrounding wall material than not, for the sake of a short fly lead I would rather have it than not have it, even a nip or a sting can cause an unexpected involuntary movement that at times is capable of causing broken legs and aching muscles , spilt paint or hot tea, not exactly common but easily avoided and yes things do happen sometimes.