It normally doesn't matter as they are on a common rail. However go with the functional earth in this case & you only need to wire the mounting box if it's metal
What "man jobs" have you done today?
- Thread starter jaybee
- Start date
My own thinking is that you wire into the Functional Earth.
The other earth sounds like you use a small bit of wire to connect the face plate earth to the earth of the mounting box itself and this may then earth the mounting box, via this connection, to the functional earth kind of like a pass through.
Soldato
- Joined
- 28 Dec 2017
- Posts
- 9,228
- Location
- Beds
Photos needed. Your cables travelling through the walls each have 1x blue, 1x brown and 1x bare earth wire. Sounds like your installers have twisted the two earth wires together then sleeved in G/Y but worth confirming.
Then assess whether you have metal or plastic back boxes. Metal ones need an earth wire, often called a pigtail, adding in which joins the the faceplate.
*need is a strong word, it's a good idea to ensure the back box stays earthed while the faceplate is off. But I think regs don't enforce it so long as the back box is earthed when the screws are done up.
Last edited:
The backbox in the wall is metal. Aren't they all?
This is the wiring we are dealing with (just pulled the old plastic faceplate off the wall)
Our other electrician actually fitted a brand new socket in the bedroom and this is what he did, sounds like what you're saying - it's going into the functional earth of the new faceplate:
This is the new socket, seems to have a common rail if I'm understanding correctly?
And instructions
@LuckyBenski pics for ya.
Last edited:
Soldato
- Joined
- 28 Dec 2017
- Posts
- 9,228
- Location
- Beds
Personally I'd send the earth from the wiring to the faceplate and let the back box earth not be in the "main chain" of earthing. The socket earth is more important.
Plastic back boxes are for hollow walls like plasterboard
Plastic back boxes are for hollow walls like plasterboard
Thanks @LuckyBenski . Seems like we can't easily find a good answer on this because even electricians argue about it.
I just found this short video which was interesting/helpful; https://www.youtube.com/watch?v=Kmu0MkE9fTc
Seems the fixed/adjustable lugs on the backboxes is the key. We have one fixed and one adjustable lugs on both the existing/old backboxes and the new one that our electrician fitted.
I just found this short video which was interesting/helpful; https://www.youtube.com/watch?v=Kmu0MkE9fTc
Seems the fixed/adjustable lugs on the backboxes is the key. We have one fixed and one adjustable lugs on both the existing/old backboxes and the new one that our electrician fitted.
For what it's worth I agree with Lucky. Earth's into socket from ring main and then a further earth out of the socket into the back boxPersonally I'd send the earth from the wiring to the faceplate and let the back box earth not be in the "main chain" of earthing. The socket earth is more important.
Plastic back boxes are for hollow walls like plasterboard
Soldato
- Joined
- 28 Dec 2017
- Posts
- 9,228
- Location
- Beds
Exactly, the back box isn't earthed while the faceplate is removed. So there'd still need to be another fault to cause a dangerous scenario, but it's still good practise to remove potential risks.
Near miss boys.
Limited/next to nothing. It is like air crash investigation; you need a series of bad decisions to be at risk. For e.g. if they didn't earth the backbox, and didn't put a grommet, and the wire had been split around the join, the backbox could be live if the decorator pulled the face plate.... or something.
Last edited:
Soldato
- Joined
- 25 Sep 2012
- Posts
- 3,213
More like pretty much a hit. Assume you going to repair that? Also yikes at how shallow that cable is.Near miss boys.
Limited/next to nothing. It is like air crash investigation; you need a series of bad decisions to be at risk. For e.g. if they didn't earth the backbox, and didn't put a grommet, and the wire had been split around the join, the backbox could be live if the decorator pulled the face plate.... or something.
Soldato
- Joined
- 28 Dec 2017
- Posts
- 9,228
- Location
- Beds
Bloody hell!Near miss boys.
Near miss boys.
Near miss? You just lost battleships mate x
It is one of three discoveries:
I yolo'ed this one^. Dead.
This one is taped and clipped so I haven't had the courage to lick it yet
I guess some wall lights were retrofitted once upon a time!
No copper no problem
No copper no problem
You were a blonde one away from angry pixies!
Near miss boys.
^and this is why we have wiring regulations.
The saying "near miss" always reminds me of the comedian George Carlin and how silly the saying is
The above is true, such as when the wiring is installed or pulled through. If such a thing was to occur you wouldn't want to rely on the threads of the faceplate screws to pass a good enough fault current to trip the circuit.
Near miss boys.
It’s stuff like this that makes you appreciate dot and dab plasterboard more.
