"TheScullster" wrote in message
. uk...
Hi all

I have been considering how to satisfy 17th Edition wrt cooker cable.
As I see it there are three options:
1 Fit RCBO in place of MCB for cooker feed
2 Use earthed steel conduit protection
3 Bury cable 50mm below wall surface.

That got me to thinking about the stability of the wall if option 3 is
used.
Allowing for plaster covering, but also the cable thickness means you will
be chasing to a depth of half the inner leaf thickness.
Also, with cable coming from above, the chase will extend 1/2 to 3/4 the
height of one storey.

So, the question is, is option 3 above actually directed at modern
domestic
installations where the inner leaf is only 100mm thick?
In the case of my kitchen, the inner blocks actually have an insulation
filled cavity "within" the block itself. So the effect of chasing to 50mm
depth (and into this cavity) is even more damaging.

Phil


There are already products
http://www.sparkyselectrical.co.uk/i...ing25wide.html
that have been around since cables were first buried under plaster. Cut
your chase to brick depth and fix your cable. Place the metal capping over
it with a few wide head nails at the edges (or drill and screw it), just to
hold it in place until you make good the plaster work.

If you really want to fulfill every regulation in the book, then you can
drill one end of the capping and fix an earth bond from it to the new socket
/ appliance point. But that is not absolutely needed. All you really want,
is to stop anyone banging a nail through the cable, which the capping has
already been designed to do.

And it's a lot cheaper in the long run, because you're not going to all the
trouble of trying to fix the other options you talk about above.

Have a look in your local wholesaler for it.