Earthing in power sockets within Stud Wall

[redbike]

I have removed several sockets located in stud walls in my 70's house. In one, the mains lead (T&E) earth went only to the earth on the metal box, not the socket itself. On three others, the earth went to the socket and the metal box earth was not used at all.

My understanding is that with any metal socket box, an earth wire must be onnected between the box and the socket.

In contrast, with a dry lining box, there is no means or need to earth the box.

Please confirm.

 

[riveralt]

For any socket the earth core must go to the appropriate terminal in the socket.
There is nothing in regulations that states that you must also attach a flylead from the socket earth to the metal backbox - some consider it best practice however.

 

[vibrobullit407]

In agreement riveralt. As long as there is a fixed lug in the back box the box screw will act as the fly lead. If both lugs are adjustable then a fly lead is required!

 

[ban-all-sheds]

the mains lead (T&E) earth went only to the earth on the metal box, not the socket itself.

Be very afraid.

The kind of dribbling idiot who could do that can't be relied on to have ever done anything properly, yet you and everybody else in the house are trusting your lives to the fact that he has.

You need to get the entire installation checked out asap.

 

[mfarrow]

Agreed that it needs to go to the accessory.

The regulations do not permit the faceplate screws to be used as part of the circuit protective conductor. This isn't explicit, but is implied by the regulation that requires the conduit systems to have a flying lead between the accessory and the backbox.

Two reason's I suspect for this - firstly, as with wiring a plugtop, you shouldn't build in a requirement to disconnect the cpc first on what is effectively a Class 1 device. Secondly, on grid systems there is a risk that the yoke screws are loose underneath the faceplate and may not provide a sufficiently los resistance oath to earth.

 

[redbike]

Thanks for the advice guys, greatly appreciated. Next question coming up...