Metal Light Switch - Metal Back Box earth cable

[sjw64]

Hi

Im replacing my plastic light switchs with brushed metal ones and I need (I think) to earth them to the metal box.

Can anyone point me to what cable I need on eBay/Screwfix etc.

Only need about a metre but unsure what type of cable.

Thanks

 

[rjm2k]

you need to provide more info and maybe post a photo of the inside of one of your switches. do you have an earth wire available in the cables going to your switches and if so is it actually connected to earth?

 

[sjw64]

you need to provide more info and maybe post a photo of the inside of one of your switches. do you have an earth wire available in the cables going to your switches and if so is it actually connected to earth?

Thanks

There is an earth cable attached to the metal box (not too clear in this photo - no sleeve - Ive got some that I will be putting on).

Untitled

• sjw64
• 18 Jun 2013
• 2

I will be putting in new boxes as well

The new metal switches have an earth screw at the back
http://www.diy.com/nav/fix/electric...tches/Single-Light-Switch-10AX-2-Way-12628661

 

[rjm2k]

afaik you can just connect the existing earth to the terminal on the switch, some people like to have a fly lead to the back box but as long as at least one of the back box lugs is fixed there isn't a need as the box is earthed via the screws on the switch.

would be worth verifying the earth is actually connected though and pvc sleeving for the bare earth

 

[winston1]

I will be putting in new boxes as well

Why?

 

[Click-Sure]

If your sticking with the same boxes you'll need to have a flylead between the switch and the back box, notice the tabs on that box are plastic.

1.5mm green&yellow 'conduit singles' should be fine.

 

[sparkwright]

It's a good idea to earth the back box and the faceplate.

I hate the idea of not earthing faceplates directly, and relying on the fixed metal lug of an earthed back box.

Absolutely hate it.

If someone was to loosen the faceplate whilst decorating, as people do, the faceplate won't be earthed.

Good idea to change those back boxes, I imagine they don't have a proper earth terminal, and possibly not deep enough, especially if you ever have dimmer switches.

 

[PrenticeBoyofDerry]

If using metal backboxes, the requirement to earth them would depend on whether the fixing lugs for the faceplate were rigid or adjustable.
If you are installing metallic faceplates it would be very wise to confirm that you have a path to earth via the circuit protective conductors at the switches, this is not a visual test but would ideally require continuity and earth loop impedance to be measured.

With regards to the cable required, you can use the bare copper of twin and earth and you could also strip back the other twin conductors, then sleeve them with green and yellow PVC sleeving.
You could also use single earth conductors.

http://www.screwfix.com/p/pvc-sleeving-3mm-x-100m-green-yellow/18132
http://www.screwfix.com/p/tower-conduit-wiring-cable-6491x-1-core-1-5mm-x-100m-green-yellow/61678