Has my power socket got an earth on back plate?

[realaledrinker]

Hope someone can help

In the picture , the top half will be plastered over (just old telephone connection we dont need) but the bottom half is a power socket, they are both on a double back plate , i.e they are one unit

Because half of it will be covered , i want to be sure the bottom half is earthed before using , and i can not see that it is

Can anyone offer advice?

ta


[img]http://i.imgur.com/XyQBVPH.jpg[/img]

 

[realaledrinker]

though it appears to have two fixed lugs so is ok?

 

[PrenticeBoyofDerry]

You have CPC/circuit protective conductors (AKA earth), or should I say you have conductors that are sleeved as CPC (green/yellow), you would not know if they were connected to earth without testing/proving this.
Depending on the new plate you use, would dictate whether you earth between plate and backbox, generally there is no need to fix a tail between plate and box, if you have fixed lugs, but if the new plate is metallic it would be wise to do.

 

[realaledrinker]

Thank you , i appreciate that

I intend to install a plastic mk faceplate , so with fixed lugs , any metal screws wouldnt become live in a fault situation ?

 

[Taylortwocities]

any metal screws wouldnt become live in a fault situation ?

No they won't become live. The earth connection on the front plate provides earthing for the fixing screws when they are in place.

 

[JohnW2]

Depending on the new plate you use, would dictate whether you earth between plate and backbox, generally there is no need to fix a tail between plate and box, if you have fixed lugs, but if the new plate is metallic it would be wise to do.

Are you saying that you would be happy for the box not to be earthed if the plate were plastic?

Kind Regards, John

 

[PrenticeBoyofDerry]

I intend to install a plastic mk faceplate , so with fixed lugs , any metal screws wouldnt become live in a fault situation ?

They could do!
But providing the you have an earth via the CPC present, the backbox and screws become earthed via a metal band, that is factory fitted across the plate's earth terminals and screw positions, which then bonds the backbox and screws to earth.

 

[realaledrinker]

Chaps , if i WAS to earth between new face plate and box , what cable do i need to buy because i read somewhere that earth cable for this purpose shouldnt be stranded?

 

[Taylortwocities]

what cable do i need to buy because i read somewhere that earth cable for this purpose shouldnt be stranded?

Throw that book away then, it is talking cr@p.

A short bit of 1.5mm² conductor (solid OR stranded and sleeved G/Y) is all that you need.

But it is not necessary to earth the back box, because it has got a fixed lug. This makes the box earthed through the front plate fixing screws when they are in place.

 

[PrenticeBoyofDerry]

Are you saying that you would be happy for the box not to be earthed if the plate were plastic?

I am saying that if you have fixed lugs, there is no requirement to do, if the plate has an earth terminal!

 

[PrenticeBoyofDerry]

Chaps , if i WAS to earth between new face plate and box , what cable do i need to buy because i read somewhere that earth cable for this purpose shouldnt be stranded?

Where did you read that?

You only need a short length that should be sleeved, either stranded or solids. You can buy stranded in singles or strip solids out of some twin/earth.
If you only need a small amount, you may have neighbour or friend with a bit kicking about or know a friendly electrician with some. Alternative is visit a local electrical wholesalers, if they will, if not give you a short length, cut a length for you.

 

[realaledrinker]

what cable do i need to buy because i read somewhere that earth cable for this purpose shouldnt be stranded?

Throw that book away then, it is talking cr@p.

A short bit of 1.5mm² conductor (solid OR stranded and sleeved G/Y) is all that you need.

But it is not necessary to earth the back box, because it has got a fixed lug. This makes the box earthed through the front plate fixing screws when they are in place.

http://www.screwfix.com/p/prysmian-6242yh-twin-earth-cable-1-5mm-x-10m-grey/87315

?

 

[JohnW2]

Are you saying that you would be happy for the box not to be earthed if the plate were plastic?

I am saying that if you have fixed lugs, there is no requirement to do, if the plate has an earth terminal!

Fair enough. I was actually (unnecessarily) thinking about accessories more generally (which don't all have earth terminals, hence don't all have earthed screws).

Having said that, as you will be aware, I am personally not all that happy with reliance on faceplate screws to earth a metal backbox. Although one obviously should not be removing a faceplate and pulling it forward whilst a circuit is live, if one does that and the pulling forward causes the live conductor to become disconnected from the accessory (which most of us have seen happen), that lose L conductor could come in contact with the (unearthed) backbox, leaving one confronted by a lot of live metal. For that reason, I personally always have an explicit (wired) earth/CPC connection to any metal backbox.

Kind REgards, John

 

[PrenticeBoyofDerry]

http://www.screwfix.com/p/prysmian-6242yh-twin-earth-cable-1-5mm-x-10m-grey/87315
?

The CPC on 1.5mm T&E will be 1.0mm not 1.5mm. I personally do fit 1.5mm, when required. But 1.0mm will do in this situation.
So likely be a wee bit cheaper purchasing 1.0mm T&E instead as the CPC will still be 1.0mm.

 

[Taylortwocities]

The CPC on 1.5mm T&E will be 1.0mm not 1.5mm. I personally do fit 1.5mm, when required. But 1.0mm will do in this situation.

Prentice, I think you misunderstand.
He linked to the 1.5mm as an example of an earth link conductor.

The (ring final) cables in the picture appear to be 2.5mm. So an earth link of 1.5mm² is what is (or is not) needed.