Plastic Mounting Boxes - With or Without Earth Terminal?

[333rocky333]

Hello!

I'm planning a ring circuit and was wondering if there any guidelines about when you need a earth terminal in a plastic mounting box. The plaster on the walls is too thin to take a 25 mm metal box so I was hoping to attach plastic boxes directly to the masonry and then make good. This should make the sockets a bit more tidy and secure than if I just surface mount them.

Cheers

If you do make sure they are level as there is no adjustment on the lugs.
I have seen it done and it is ok just looks like a 15 mm surface patress

 

[GaryMo]

In the Snags and Solutions book by the NICEIC they state you don't need to earth the backbox providing there's a fixed lug present.

This was discussed before and an nic man said they like to see it even though it is not written,everyone i know does It, and if I find a socket without I will do that also.

Your 'nic man' is like all of us, he has an opinion.

Hope you don't do any work in new houses otherwise you'll be needing JohnD's Paypal details

 

[333rocky333]

!

BTW, I always earth metal backboxes

I dont do domestic
What is the norm now then in houses , I read that you take the earth to the front and thats it now
You say you earth yours ,how by taking one of the 1.5 core to the box and then to the front and part of the ring.

Back in the day we would put the short earthwire in the box before fitting in the wall, then when second fixing just simply connect three direct into the front, even easier now with the two earth lug sockets

 

[Spark123]

What is wrong with using a bit of 1.5mm for the link to the back box? 2.5mm T&E has a 1.5mm CPC, just a bit stripped out of there is as good as anything.
Connect all the circuit earths to the socket front and run a link to the back box, the back box earth terminals are not brilliant at the best of times.

 

[GaryMo]

The current trend in new houses is to take both CPC's to the socket face with no link to the backbox.

I always take both CPC's to the socket face but also connect a 1.5mm link to the backbox.
I don't do new houses though and if I did I doubt i'd be fast enough to earn the right money. Speeding up would mean lowering standards which I'm not prepared to do.

 

[Mad_Doctor_X]

Thanks for the tips!
The house is late 19th so I'm not sure I'd be happy hacking out the brickwork, especially as I need to take about 1 cm out of a shared wall (it's a terrace). I'd need all the permissions then and it's just asking for trouble!

So am I right in saying that although mounting plastic boxes directly to the bricks is unusual, there is nothing wrong/dangerous with it? That's in both the hypothetical and legal (the regs) sense!!

Thanks again

 

[GaryMo]

So am I right in saying that although mounting plastic boxes directly to the bricks is unusual, there is nothing wrong/dangerous with it? That's in both the hypothetical and legal (the regs) sense!!

Go for it, nothing there to stop you.

Bear in mind that most houses have joining walls and I've yet to ask permission of a neighbour before knocking backboxes in.