Depth of cables ?

[sevetaz]

I qualified under 17th edition and having trouble getting any documentation on the 16th edition, i would appreciate any advice you can give. Currently decorating my kitchen in a rented bungalow. The CU is located in a base unit and the cover can only be opened if i take a drawer out and then obviously remove everything in the cupboard as well, the meter is also in the same cupboard!!, I removed the wall tiles above the CU to find that all the cables from the CU running vertically into loft space, the plaster had been channelled at max of 5mm, cables then clipped into wall and then 9mm plasterboard over the top so max cables are away from surface is just the depth of the plasterboard itself and has no protection over cables. I have asked to be able to move the CU above the wall units using less than 3m meter tails. They are saying that the wiring problems i have found complied with the regs when it was installed (16th edition) although i cant find nothing on the internet as yet i cant believe this can be right.
Is there a min depth under 16th and also should the CU be readily accessible ?

Sorry to add plumbing but this is the same property where i have just found the main stop cock hidden behind a fitted base unit with no access to it so there is little hope !!

Many thanks

Nigel

 

[telectrix]

there is no problem with the cables being as they are, but they should be RCD protected under 17th Ed. regs. this was not necessary under the 16th.

 

[sevetaz]

many thanks for the quick reply quite frightening then really that someone without much savvy could drill straight into them as they are

 

[Deleted member 26818]

The only change between the requirements of the 16th edition and the 17th, is the additional requirement to provide RCD protection to cables run in prescribed zones.

 

[brman]

many thanks for the quick reply quite frightening then really that someone without much savvy could drill straight into them as they are

But didn't you say they were all running vertically from the Cu into the loft? that is a prescribed zone so not somewhere anyone should be drilling anyway. No different in the 17th except the need for the RCD. Doesn't stop you damaging the cables, just helps stop you killing yourself

 

[sevetaz]

yes they are vertical as such they run at 90 deg from the Cu for about a foot before running vertical so you would like to think people would notice that before drilling etc, does make me wonder though as whoever put the wall units up have missed the cables by about an inch putting the brackets up

 

[brman]

yes they are vertical as such they run at 90 deg from the Cu for about a foot before running vertical so you would like to think people would notice that before drilling etc, does make me wonder though as whoever put the wall units up have missed the cables by about an inch putting the brackets up

Ah, not really in the prescribed zone then if they run horizontally first. I wouldn't worry though if they are visible by the CU. I do agree though, although it is pretty common it isn't great when a kitchen fitter is going to just put the screws where he wants for the top cupboards. Most of the time they get away with it!

 

[HandySparks]

Is there a min depth under 16th ...

No minimum depth but, referring to my copy of the Electrician's Guide to the Building Regulations, there is a maximum depth for chases in walls of one third of the wall thickness for vertical runs and one sixth for horizontal.

So, ignoring plaster, for a typical 4 inch thick brick or block, 34mm vertically and 17mm horizontally.

 

[telectrix]

that's only so the wall doesn't collapse after you've butchered it. raise you CU, make everything RCD protected, cables in prescribed zones. just got reservations on the tails. how will they be protected from the meter to the CU?