Code of Practice for the Electricity (Wiring) Regulations - 2009 Edition

(a) the ambient temperature does not exceed 35°C;
(b) no more than one circuit of single core cables or one multicore cable
are to be grouped together;
(c) for cables clipped direct on surface, the spacing between groups of
single core cables or multicore cables is not less than twice the
diameter of the largest cable in the adjacent group of cables;
(d ) the protective device is not a semi-enclosed fuse; and
(e) the cables are not in contact with any thermal insulation.
13B Basic Protection
(1) Protection by electrical insulation
(a) Live conductors should be completely covered with insulation which:
(i) is durably withstanding the mechanical, electrical, thermal and
chemical stresses to which it may be subjected in service; and
(ii) can only be removed by destruction.
(b) Where insulation is applied during the erection of the installation,
the quality of the insulation should be verified by tests equivalent to
those specified in recognised standards for similar type-tested
equipment.
(c) Non-impregnated paper, asbestos, fabric, wood or press-hemp
should not be used for insulating purposes.
(d ) Where insulating tapes are permitted to be used in low voltage
installations, they should have a minimum thickness of 0.21 mm.
(2) Protection by other means
Other means of basic protection as stipulated in IEC 60364 or BS7671 are
acceptable.
13C Joints and Connections
(a) Every connection at a cable termination or joint should:
(i) be mechanically and electrically sound;
(ii) be protected against moisture, mechanical damage and any
vibration liable to occur;
(iii) not impose any appreciable mechanical strain on the fixings of the
connection;
(iv) not cause any harmful damage to the cable conductor;
(v) be appropriate to the size and type of conductors with which they
are to be used; and
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