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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Running Cables in walls https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1096405718 Message started by DoWellSon on Sep 28^th, 2004, 10:08pm

Title: Running Cables in walls
Post by DoWellSon on Sep 28^th, 2004, 10:08pm

Reading the OSG Sec 7 pg 53, regarding permitted cable routes. I'm a little unsure of the intent of running horizontally.
Can you run cable horizontally between two sockets? The wording seems to indicate that the only time you need metal conduit is for diagonally and less than 50mm below surface. I ask as haven't seen it run horizontally between sockets and was under the impression it was a no no. Any thoughts?

Title: Re: Running Cables in walls
Post by JerryD on Sep 28^th, 2004, 10:53pm

I was also under the impression that this was a no no but the OSG clearly says this is ok. �You must run horizontally or vertically from the faceplate.

Diagonally is still a no no unless it is deeper than 50mm or is enclosed in earthed metal trunking or conduit.

So a 100mm thick partition wall is not suitable for the 50mm deep rule as far as I can see.

Title: Re: Running Cables in walls
Post by plugwash on Sep 29^th, 2004, 1:33am

horrizontally from an accesory is a permitted route by regs but most sparkys consider it bad practice nonetheless

kinda like running a shower cuircuit with no rcd the regs allow it but that doesn't mean most sparkys think it is a good idea

Title: Re: Running Cables in walls
Post by DoWellSon on Sep 29^th, 2004, 8:51am

Thanks - just wanted clarification. I read it that you could but agree it appears to be bad practice.

Title: Re: Running Cables in walls
Post by fubar on Sep 30^th, 2004, 2:43pm

wrote on Sep 29^th, 2004, 1:33am:

horrizontally from an accesory is a permitted route by regs but most sparkys consider it bad practice nonetheless

Partly because it encourages people who don't know better to run horizontally into the corner and then along the adjacent wall. Very bad as the 90 degree change of direction would have a tiny bend radius that would be well outside the permitted bend radius and could cause heating of the cable or even break the conductors - either of which coud cause a fire.

And partly because a deep channel could seriously weaken the structural integrity of a solid wall.

Title: Re: Running Cables in walls
Post by sparkyjonny on Oct 17^th, 2004, 7:42pm

Hi everyone - just moved over from Screwfix - fed up of it being down all the time!
Does anyone know what NICEICs recommendations for running under a bay window or in a dwarf wall on a conservatory is? I know horizontal runs would be acceptable if there is an accessory mounted on each angle of the wall, but what about if a customer wants a socket on a section of dwarf wall without any on the adjacent sections? - i'm thinking of the common rectangular conservatory with half a hexagon on the end. Is it just a case of either underground or earthed capping? Or is the top of the dwarf wall or bottom section of wall beneath a bay window classable a standard wall, so cables can be routed all the way around within the top 150mm?
Cheers guys.

Title: Re: Running Cables in walls
Post by JerryD on Oct 17^th, 2004, 7:48pm

The permitted zone is 150mm down from the ceiling, so you can't run it horizontally in the dwarf wall as you suggest. �Run it under the floor or in an earthed conduit.

I know the regs say 'within 150m from the top of the wall' but from the osg picture it looks like they mean from the ceiling.

Title: Re: Running Cables in walls
Post by Lectrician on Oct 17^th, 2004, 9:17pm

That good old question - we use SWA in concervatories under the floor screed. Use 35mm deep boxes in the wall, and terminate the swa via conduit couplers and serrated washers/bushes into the galv back box.

Title: Re: Running Cables in walls
Post by sparkyjonny on Oct 18^th, 2004, 9:38am

Like that idea Lectrician. I assume SWA could also be run horizontally, as the earthed armour gives it the same level of protection (if not more) than that offered by earthed steel capping? May need a channel chasing into the brickwork though...

Title: Re: Running Cables in walls
Post by L.Spark on Oct 18^th, 2004, 12:08pm

SWA provides 'mechanical protection' same as steel capping does

Title: Re: Running Cables in walls
Post by plugwash on Oct 18^th, 2004, 1:36pm

if you want something thinner than SWA which can be chased in directly out of zones you could consider MICC

from what i c an gather the stuff is trikier to work with and pricier than SWA though

Title: Re: Running Cables in walls
Post by sparkyjonny on Oct 18^th, 2004, 4:53pm

Yeah - the size is tempting, but heard that its a nightmare to terminate unless you're experienced. Anyone had experience of pyro?

Title: Re: Running Cables in walls
Post by supersparky on Oct 18^th, 2004, 5:03pm

yup, never ever try and rush the making off process ::)
and make sure ya test it after terminating- would be a bitch to find it fails after its all plastered up ;)

ss

Title: Re: Running Cables in walls
Post by L.Spark on Oct 18^th, 2004, 5:07pm

Unless you have done it before, don't ;)

SWA much quicker, works out cheaper too, 3-core, so armour is not sole earth, and then doesnt matter if the gland is not the best.

Title: Re: Running Cables in walls
Post by The_Trician on Oct 18^th, 2004, 6:21pm

SWA much quicker, works out cheaper too, 3-core, so armour is not sole earth, and then doesnt matter if the gland is not the best.[/quote]

Armour must be earthed properly L/S, otherwise it could remain LIVE under fault conditions, regardless of whether an integral core is used as the cpc instead.

No good earthing via an extra cable core if there is a risk that the armouring could become live without being detected, so gland termination should be done properly regardless mate.

TT

Title: Re: Running Cables in walls
Post by L.Spark on Oct 18^th, 2004, 8:37pm

You know what I meant, if it's done with a copper core, then it would effectively have double earthing, because both earths would have to be connected together.