Earthing on plastic plug sockets

[brayleyboy]

I hope somebody can help.

Over the weekend I have replaced some pretty old plastic plug sockets with some new plastic ones i bought at screwfix. The old double sockets had one terminal each for live/neutral/earth. Each terminal was wired up to the relevant wire from both the circuit cables (i.e. both live cables into live etc.) which is what i expected.

The new sockets still have one live/neutral terminal so I have wired these up in the same way. However the new socket has 2 earth terminals. At present I have just wired up both earth wires to one of the earth terminals, but should the earth from 1 circuit cable be wired up to one terminal, and the the earth from the other circuit cable to the other?

The question I have is, is it essential that I change it, and if so does it matter which earth goes to which terminal? Also there doesnt seem to be an earth cable attached to the metal back box, is this essential?

I have not yet replaced the fuse for the circuit with the sockets in, and would welcome some advice.

Many thanks

[ultimatehandyman]

I hope somebody can help.

Over the weekend I have replaced some pretty old plastic plug sockets with some new plastic ones i bought at screwfix. The old double sockets had one terminal each for live/neutral/earth. Each terminal was wired up to the relevant wire from both the circuit cables (i.e. both live cables into live etc.) which is what i expected.

The new sockets still have one live/neutral terminal so I have wired these up in the same way. However the new socket has 2 earth terminals. At present I have just wired up both earth wires to one of the earth terminals, but should the earth from 1 circuit cable be wired up to one terminal, and the the earth from the other circuit cable to the other?

The question I have is, is it essential that I change it, and if so does it matter which earth goes to which terminal? Also there doesnt seem to be an earth cable attached to the metal back box, is this essential?

I have not yet replaced the fuse for the circuit with the sockets in, and would welcome some advice.

Many thanks

You should really put one of the earth wires into each of the earthing terminals as this is how it is shown in the IEE on site guide. You should also really put an earthing wire from the socket to the backbox, this is known as supplementary earthing.

You can see how to do this on this page that shows how to change a light switch..- http://www.ultimatehandyman.co.uk/repla ... switch.htm


It's worth doing it the correct way. I have no idea why the earth wires should go into each terminal as most of the sockets I have changed have always been wired to just one terminal. I am sure there is some reason for it.

[brayleyboy]

Thanks for the quick reply. I will change the way they are wired.

Although I would be interested to know why it makes a difference if anybody knows.

Does it matter which earth I put into which terminal? And which earth terminal I use to supplementary bond to the back box? or both?

Also can I buy earth wire at B&Q/Focus etc and is there a special type for this? Also one of my sockets doesnt have the green/yellow sleaving on the earth wires, where can I get that?

Thanks

[skiking]

B&Q sell both the sleaving and earth wire

[ultimatehandyman]

Sparkydude will know the reason for putting one wire in each terminal, perhaps it is a fail safe incase one drops out, there is always the other one?

It doesn't matter which earth wire goes to which terminal, or which one you put the supplementary earthing wire into.

You should be able to get some earthing wire from B&Q although you will pay through the nose for it. A specialist electrical shop would be better as they will sell you one meter etc. The green and yellow sleeving can be bought at most places and costs pence.

Normally the earthing wire for the supplementery bonding is cut from the cable that is being used to supply the circuit, a piece is cut and then sheathed with green and yellow sleeving. I think for sockets it should be 1.5mm wire.

[uncle buck]

Putting both earth wires in the same terminal is perfectly acceptable.

[brayleyboy]

Thanks for all the info

i feel confident doing this work, however can anyone confirm whether I would be breaking any regulations doing it myself?

Also I dont believe the back boxes have specific earthing terminals for supplementary earth, is it ok to use one of the spare fixing brackets (for use with the old style face plates with two screws at the top and two at the bottom)?

Thanks

[ultimatehandyman]

Like for like replacement of electrical items is allower under the new part p rules, unless they have changed them again

Iv'e never seen any boxes without the earthing terminal, but I can't see a problem attaching the earth wire to where you suggest.

[sparkydude]

theres no reason why both earths should not go ointo one terminal, it is just the way that some manafacturers make their sockets. The MK sockets we use only have one earth terminalin the socket and this is fine. but we do use double sockets with two earth termianls for sockets feeding computer equipment and these circuits have their own high impedance earth ring main so for these circuits you need the two earth terminals as its a bit tight to get two 4mm earths and the two 2.5 earths from the circuit into the one terminal LOL.

As UHM says just make sure you have a supplementary bond from the socket earth termianl to the back box earth terminal if fitted.

Nick

[brayleyboy]

Many thanks for all fo your help everyone. My mind has been put at rest.

I will add the supplementary bonding.

Cheers