In article ,
TheScullster wrote:
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.

If those are truly the only options it makes me wonder what planet these
'legislators' are on.

A leakage operated device is often bad news for anything with certain
types of heating elements

Proper steel conduit is expensive and requires skill and special tools to
install.

Chasing two inches into the average wall for a whole cable run will likely
weaken it.

--
*El nino made me do it

Dave Plowman London SW
To e-mail, change noise into sound.