Question about routing cables?!

claire_r · Jun 25, 2009

Hey all, =0)

I know the regs say about routing cables either vertically or horizontally of accesories or 150mm from the edge of a wall but is that the be all and end all with 17th edition or is it a recommendation? If the circuits are rcd protected, which they should be if you are rewiring, then does it matter where you put the cables? Best practice or law?

Thanks everyone

(ps : still wish I was at glastonbury boooo at electrician wages hehe)

Spudnik · Jun 25, 2009

You must still stick to the zones.

RCD are for ADDITIONAL protection.

claire_r · Jun 25, 2009

even if metal capped?

ps hello jason

Spudnik · Jun 25, 2009

claire_r said:
even if metal capped?

ps hello jason

Hi Claire,

Yup.

the only other alternative is steel conduit.

Mark.W · Jun 26, 2009

The Spark I was working with on Wednesday was using PVC capping for the switch cables!
The wall chase was only about about 30mm deep, and the circuit was protected by an RCD, so how does that stand with the regs?

I was under the impression that any cables buried in a wall less than 50mm should be in metal conduit and protected by an RCD!!

electricAl · Jun 26, 2009

Brightspark said:
I was under the impression that any cables buried in a wall less than 50mm should be in metal conduit and protected by an RCD!!

Swap the "and" for an "or"

Then you`re basically there

But, if the latter, they do need to be in the prescribed zones

Mark.W · Jun 26, 2009

Thanks electricAl !!

Can we use metal capping instead of conduit if no RCD? or does it have to be metal conduit?

ajelec10 · Jun 26, 2009

Metal capping can not be used for two reasons
1. it is not deemed to be sufficient machanical protection (ie its not thick enough)
2. The steel machanical protection requires adequate earthing witch you can not do with capping
steel conduit is thicker and would be connected to the earth back box via a bush and coupler
Regards
AJ

Lou7 · Jun 29, 2009

Buy yourself a coil of flexishield, bit expensive but no RCD required, comes in all sizes even 3c+e 2.5, 4c+e 2.5

It's good stuff, use it for sw drops.

plus earth is equal size.

chocolate · Jun 29, 2009

Hi all,

Metal capping ?????? Surely a need to earth this if installed with cables ? Doesn't it become an exposed conductive part 9 something metallic that was installed as part of the installatoion ) and so needs to have a connection to earth ? Unlike conduit which is linked to trunking or metal flush boxes via brass bushes and couplers, metal capping has no such luxury !!!! Am interested to hear feedback on this !!!!!

In addition, does this apply also if when rewiring properties, the original metal conduit used for switch drops is adopted ?????

Darkwood · Jun 29, 2009

chocolate said:
Hi all,

Metal capping ?????? Surely a need to earth this if installed with cables ? Doesn't it become an exposed conductive part 9 something metallic that was installed as part of the installatoion ) and so needs to have a connection to earth ? Unlike conduit which is linked to trunking or metal flush boxes via brass bushes and couplers, metal capping has no such luxury !!!! Am interested to hear feedback on this !!!!!

In addition, does this apply also if when rewiring properties, the original metal conduit used for switch drops is adopted ?????

Regarding your second query, just think of it as though you drill the conduit with a masonary bit or try hammering a nail through it if the conduit is strong enough to resist a accident of this nature then it will surfice but be weary as old conduits are usually light gauge and not up to the job also as more often then not their extend into the loft or under the floor therefore earthing is an issue as these old runs are usually broken up.