Metal light switches wiring

[Tentontousand]

Thought I'd ask this before I burn down my home. I'm changing all the plastic light switches to metal fittings and as wondering if I needed to earth the switch plate itself if the back box is earthed?

IMG_20190112_110013

• Tentontousand
• 12 Jan 2019

 

[bernardgreen]

Earth the front plate as that is the metal that will be touched.

Cable earths to the front plate and a link wire from there to the back box

Earthing the back box requires continuity from back box to the metal front plate via the screws holding the plate to the box. Loosening over time and /or corrosion can break that continuity and leave the plate un-earthed

 

[Tentontousand]

Earth the front plate as that is the metal that will be touched.

Cable earths to the front plate and a link wire from there to the back box

Earthing the back box requires continuity from back box to the metal front plate via the screws holding the plate to the box. Loosening over time and /or corrosion can break that continuity and leave the plate un-earthed

Okay so should I remove the box earthing over to the front plate? Or do they both need to be earthed?

 

[bernardgreen]

Or do they both need to be earthed?

Important that ALL Earths in cable are connected together and to the front plate.

Earthing the back box with a link wire from the front plate earth is highly reccomended as a fault could make the back box Live if the continuity through the fixing screws fails.

You MUST also ensure there is continuity of the Earth from each switch to the Main Earth Terminal at the consumer unit itherwise you cannot have a metal front plate

 

[Tentontousand]

Important that ALL Earths in cable are connected together and to the front plate.

Earthing the back box with a link wire from the front plate earth is highly reccomended as a fault could make the back box Live if the continuity through the fixing screws fails.

You MUST also ensure there is continuity of the Earth from each switch to the Main Earth Terminal at the consumer unit itherwise you cannot have a metal front plate

Okay I'll get some copper wiring and fly between the plate and box.

Does this image show that there is continuity with the earth on the consumer unit? All starting to go over my head now

 

[bernardgreen]

Does this image show that there is continuity with the earth

Continuity can only be checked with a continuity tester.
The image suggests there is an Earth from the cutout to the consumer unit.

Does the bonding ( earthing ) of the gas and water (?) pipes connect to the Earth in the consumer unit ? There does not appear to be that essential connection.

 

[Taylortwocities]

Does the bonding ( earthing ) of the gas and water (?) pipes connect to the Earth in the consumer unit ? There does not appear to be that essential connection.

Indeed, they seem to disappear into the floor. I would have though that they should connect to the MET in the CU.

 

[bernardgreen]

they should connect to the MET in the CU

They should. or to an external MET that is coonected to the Earth bar in the CU.

It also looks like a new consumer unit (steel 18th Ed. ? ) yet old ( red / black ) cables so I wonder when and by whom the CU was installed, Lack of bonding suggests the installer did not fully check his work.

Might be worth smollians getting an EIC ( Electrical Installation Condition ) report or similar on the installation.

 

[Tentontousand]

They should. or to an external MET that is coonected to the Earth bar in the CU.

It also looks like a new consumer unit (steel 18th Ed. ? ) yet old ( red / black ) cables so I wonder when and by whom the CU was installed, Lack of bonding suggests the installer did not fully check his work.

Might be worth smollians getting an EIC ( Electrical Installation Condition ) report or similar on the installation.

Hmm I'm not actually sure where that earth goes. The CU was installed Dec 2017 but I'll get an EIC report just to be safe. Do you know how much they usually cost?

This sentence was grabbed from the CU installation certificate;

"Existing Installation was old fuse wire type board. Meter Tails undersized for 100Amp DNO fuse. Main Earth to DNO supply was inadequate at
4mm. New Consumer Unit installed with Split load 2x RCD and upgraded Earth to 16mm and Live Conductors to 25mm to DNO supply. and 10mm
Protective Bonding Conductor to Gas pipe"

 

[Tentontousand]

Also FYI these wires circled red aren't a part of the CU. Its a kettle lead and an ethernet cable.

 

[Tentontousand]

Is a 1.5mm stranded earth cable okay to use as a fly between the back box and the metal face plate?

 

[EFLImpudence]

Yes.

 

[conny]

Shouldn't those earth bonding wires be connected before that branch?