Cable Routes and Protection
Some basic rules for the installation of cables to protect them from damage in domestic properties.
Cables in a wall or partition
A cable concealed in a wall or partition must
a) be at least 50mm from the surface [note 1], or
b) have earthed armouring or an earthed metal sheath (eg SWA, a BS 8436 cable or MICC cable), or
c) be enclosed in earthed steel conduit or trunking, or
d) be provided with mechanical protection (3mm steel is deemed sufficient to meet this requirement), or
e) be installed in a safe zone .
The 17th edition also requires cables in the safe zone to have 30mA RCD protection if not installed as per a, b, c or d.
Note 1 - If the wall or partition is made from or partially made from metal then the cable will require RCD protection or be installed as b), c) or d) above
The 18th edition makes use of RCD protection mandatory for sockets and lighting circuits.