Earthing

[Marc Lajevardi]

Afternoon all, just wondering if i need to buy a metal clad back box in order to earth a metal front plate?
Ive got plastic ones in and just want the fronts changed to this..

LAP 13A 2-Gang SP Switched Socket & USB Charger Black Nickel Flat Plate | Switches & Sockets | Screwfix.com

thanks

 

[telectrix]

by plastic, do you mean cavity boxes or pattresses?

 

[malcolmsanford]

Some pattresses do have earthing terminals, and I guess you could fit a metal faceplate to it ................but not sure why you would want to.

Can't remember if dry liner boxes have earth terminals though

 

[hightower]

Dry lining boxes I've just used had no earth terminals.

 

[Simonslimline]

The cpc's terminate in to the earth terminal on the socket.

Whether you have a metal back box or a plastic dry lined box makes no difference at all.

Obviously if you have a metal surface mounted patress, put a flying earth lead to it.

 

[Marc Lajevardi]

by plastic, do you mean cavity boxes or pattresses?

cavity, sorry

 

[Marc Lajevardi]

Dry lining boxes I've just used had no earth terminals.

the ones in mine dont either mate, which is why im wondering if i should swap for metal ones which do

 

[hightower]

I'm not sure of why you think that? Surely a plastic back box is fairly safe, and the faceplate itself will be earthed with your cpc? By swapping tou a metal back box with a tail to your cpc you're no further forward and no better off?

 

[Marc Lajevardi]

The cpc's terminate in to the earth terminal on the socket.

Whether you have a metal back box or a plastic dry lined box makes no difference at all.

Obviously if you have a metal surface mounted patress, put a flying earth lead to it.

so a metal surface with a dry line back box doesn't need earthed?

 

[hightower]

The back box won't, but the faceplate will be connected to your cpc

 

[Marc Lajevardi]

I dont think anything mate, thus the reason for question, it popped into my head as i heard something about having to seperately earth if the plate was metal, so im just putting it to you guys to double check

 

[hightower]

I dont think anything mate, thus the reason for question, it popped into my head as i heard something about having to seperately earth if the plate was metal, so im just putting it to you guys to double check

I'm just a trainee too so don't take this as gospel but unless I'm completely missing something, the CPC of your circuit will provide the earthing you need when connected to the earth terminal of your metal faceplate. Changing to a metal back box with a fly lead would be no different to having a plastic back box, and earthing a plastic back box would be as productive as using chocolate to make a frying pan.

 

[Simonslimline]

Terminate the socket as you would always do with the respective Line, Neutral & CPC connections.

You cannot earth a plastic pattress or a plastic dry line box by the very fact they are plastic.

If you have a metal surface pattress, then this in an exposed conductive part and should be earthed.
A metal recessed back box will have an earth connection on it, good Practice is to take a flying lead to the back box from the accessory. If the back box has a fixed lug then not strictly necessary.
A plastic dry line box cant be earthed anyway due to the fact it is plastic.

 

[Marc Lajevardi]

leave as is then, thanks buddy, aye a know not to try and earth a plastic back box

 

[Marc Lajevardi]

yeah i know i cant earth the plastic ones mate, it was a case of if i should get a metal one, thanks for the advice mate