On Nov 17, 11:19*pm, "BigWallop"
wrote:
"Martin Carroll" wrote in message

...



In article , Andy Burns
writes
Martin Carroll wrote:

Why not? *AIUI as long as a cable runs in a line horizontally or
vertically to an accessory or within 150mm of top of wall or angle
formed by two walls.

Used to be, now 17th edition requires either

cable is buried more than 50mm

or

cable is not buried at all

or

conductors are fully enclosed by an earth (e.g. T&E within earthed metal
capping, or a cable such as SWA, or BS8436 cable with foil screen, or
pyro etc)

or

protected by 30mA RCD or RCBO

or

something else I missed?

In the 17th Edition OSG, (page 60)

A cable installed in a wall or partition must:

i * *be at least 50mm from surface
ii * have earthed armouring.....
iii *be enclosed in earthed steel conduit....
iv * be provided with mechanical protection......
v * *be installed either horizontally.........

In domestic and similar installations, cables not installed as per i,
ii, iii or iv but complying with v shall be protected by 30mA RCD.

So as long as there is an RCD in CU protecting the circuit cable can be
unprotected in the "safe" zones.

Cheers

Martin

To comply with the 30mA RCD ruling, you won't be able to run a fan heater or
anything else of that nature on the final ring. *In fact, one PC may be
enough to trip a 30mA RCD because of the feedback to earth from the
switching PSU. *Try it, though.

First it was burning transformers with 10% overload, now SMPSs that
will trip 30mA RCDs.

What next?

MBQ