Two Red Wires into Earth Terminal on back box (Two Gang)

[ben123d]

I am changing a two gang light switch from a older plastic version to a metal one.

Moving the earths from the back box to the earth terminal on the light switch / plate, but on the two gang on the landing there are two red wires going into the earth terminal in the back box.

Do these get moved to the earth terminal on the light switch or remain where they are?

 

[oldbutnotdead]

You may find that those 2 red cores are live and some lazy installer has used the terminal in the plastic box instead of going back to their van and getting a piece of choc block. Or I've misunderstood and the landing switch has a metal backbox?

Before doing anything you should check that the CPCs (the bare conductors) or anything else you think is ground are actually connected to ground- with your old plastic switchgear lack of earth is not a problem, with your metal switch bad things could happen.

EDIT Good practise to link from the earth terminal on the switch to the earth terminal on the backbox

 

[ben123d]

It's a metal back box and metal switch. Just tested both wires with a multi meter and it's showing nothing for both. I assume they have just been 'parked' in the box terminal

 

[oldbutnotdead]

OK. So is there any other sort of earth wire at the landing switch?- if not, you can't use your new metal switch. Out of interest, what did you test the red wires against?

 

[ben123d]

OK. So is there any other sort of earth wire at the landing switch?- if not, you can't use your new metal switch. Out of interest, what did you test the red wires against?

I tested against the back box. Got a reading off the live going into L1, but nothing off the two reds going into the earth terminal on the back box.

Apologies, should have been clearer in the original post. There are two earths also going into the back box earth terminal.

I have now sleeved both and put into the earth on the switch plate. I have a put a fly earth from switch plate to back box. I have left the two 'dead' red wires in the earth terminal on the back box.

Just switch the lights back on at the consumer unit and tried the switch, no problems. I have also tried the downstairs switch controlling the same lights, no problems (i.e. I'm still alive and not tripping).

 

[EFLImpudence]

Putting wires in an earth terminal is a way of terminating them safely and showing that they are unused and not live.

Put them in the switch terminal with the earth wires.