Metal for plastic switch replacement...

[macman]

I'm just about to swap out the old plastic switch here for a new metal one.
Could someone please confirm that I need to run an additional earth lead from the switch to the back box, which is already earthed. See pic.
I've seen other posts but I really want to be completely sure before I do this! And I promise to switch off power at the CU before fitting it!

Thanks in advance, MM

 

[EFLImpudence]

You could do that - or connect the existing earth wire to the switch.

 

[macman]

You could do that - or connect the existing earth wire to the switch.

Ok thanks for the reply - but don't I need to ensure a proper earth from switch to back box, rather than just rely on the two screws earthing the whole lot? I guess I'm looking for a definitive "do it this way" kind of advice!

 

[EFLImpudence]

It is not a requirement to also earth the back box but a lot of people like to do it so it is up to you.

The only definitive thing is the metal switch must be earthed.

 

[terryplumb]

"Do it this way kind of advice".....
Connect the earth conductors to the switch plate earth terminal ,and add a flying earth link from that terminal to the galvanized back box earth terminal as well. Current regulations don't require the link to the galvanized box ,if it has a fixed lug and metal screws. But previous regs did ,and most sparks that I work with still do it the former way ,I guess old habits die hard !!!

 

[EFLImpudence]

Current regulations don't require the link to the galvanized box ,if it has a fixed lug and metal screws.

I think you will struggle to find a regulation which states that because there isn't one.
The fact is that a buried back-box is not an exposed-conductive part and so does not require earthing.

But previous regs did,

Are you sure that it is not another myth like the 15th required bonding to everything - and your first line.

and most sparks that I work with still do it the former way ,I guess old habits die hard !!!

They do - even if there was no actual reason for it in the first place.

 

[macman]

Guys, thanks for your input, it's much appreciated.