Cables to be installed in ducts or pipes in the ground
are not required by BS 7671 to have armouring and/or
a metal sheath, if the duct or pipe is sufficiently
strong to resist likely mechanical damage. In case of
doubt, a cable fulfilling the requirements of
Regulation 522-06-03 should be provided.
Protective conductors which are buried directly in the
ground must comply with the requirements of
Regulation 542-03-01.
All buried cables must be marked by cable covers or a
suitable marker tape, and buried conduits or ducts
must also be suitably identified. A warning tape
above the duct or conduit run would be suitable.
Cables, conduits and ducts must be buried deep
enough to avoid being damaged by any disturbance
of the ground reasonably likely to occur. This could
include gardening/horticultural works, excavating for
any local buried service pipes etc. Generally, it is better
to locate cables etc. clear of such possible works.
A depth of burial of less than 500 mm is usually
inadvisable as shallow laid cables may be
inadvertently damaged by general gardening etc.
Cables that cannot be buried at a reasonable depth
should be specifically protected, e.g. by ducts encased
in concrete, or installed along an alternative route.
Before any excavation is undertaken for cable or
other works HSE guidance booklet HSG47 "Avoiding
danger from underground services" should be
studied, as it provides valuable advice on safety
aspects.
It is important to be able to identify exactly where
hidden services are located and accurate records,
including drawings, should be made before trenches
are backfilled. Cable routes should be located on
drawings by dimensions from some fixed object that is
not expected to change for a considerable time, (e.g. a
building). Road and pathway features may be relatively
easily changed. Scale drawings are of little value unless
very detailed. Concrete route markers may be installed
at changes of direction of cable routes and at regular
intervals along routes.
PS Where is the fcuking kek to the front door wabbit