No Earth in dry lining, and extending wires!

[Athy]

Hi! We have knocked out our porch and built a false wall by the stairs of... MDF... We want to relocate the light-switches that were on the porch wall onto the new false wall.. However, when we took up the floorboards upstairs and poked the wires down through a new hole, they were only a foot long from the ceiling.

We need to extend the wires - 2 x One Way (for porch light and lounge light) 1 x Two Way (upstairs landing light). Can we put them all in one switch or are we better with two? We have bought Joining blocks is this safe in an MDF wall? We have bought a couple of Dry-Lining boxes but they have no earth screw in them... How do we earth them? We intend to get metal switches...

Many many questions I know, but please HELP!

 

[Steve]

Can I ask what you think the point of earthing plastic boxes is? A lot of these dont come with earth screws. But with metal switches, the faceplate will have an earth terminal.

Buy a 3G 2W switch.

All connections must be accessible - I suggest another dry lining box in the wall, with a blanking plate. If not, renew the cables from origin, or in the loft - this is accessible.

 

[Jaymack]

Since the cables will be hidden and not accessible for inspection, the cable cores should be extended using crimped or soldered joints, the crimping is carried out using the correct ratchet tools and ferrules, soldering should be done by someone with experience in soldering. The use of terminal blocks in this context is against the regulations. Dry lining boxes do not require an earth connection. The routing of the cables within the walls requires to comply with the regulations, there are designated areas for cables inside walls. The final installation should be fully tested by a competent electrician: - Insulation, Polarity, Source Impedance and Protection characteristics etc.

 

[Athy]

Sorry Yes of course I understand now about the plastic box thingy, its just that the ones we took out of the old wall were metal and had a little screw in the back of them, and these new plastic ones have a hole where it looks like the screw is missing thats all... Being new to all this we just dont know certain things thats all

Being also new to electrics, i think we'd rather try to join the wires (one is a ring main tho) rather than replace the whole piece...

 

[Athy]

Hmmm... okay... Trouble is, most posts that are slightly similiar about extending the wires say about a 30amp Junction Box... (I have spent hours here trying to find answers)... Will these not suffice? And what about being in a wooden wall? Is that silly?

 

[Steve]

You cannot enclose a 30A JB in a wall. It must be accessible. Like I said, use terminal blocks inside another dry lining box in the wall where the joint needs to be, and face it with a blank plate.

 

[Athy]

Yes I think we will do that, they will be up high so it wont matter anyways, and on the stairs side of the new wall...

Should we use a dry-lining box for each wire separately? Then all come down into the one switch?

And what do we do with the earth wires? If we have metal switches, the earth wire in there, where does that go?