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MERLIN 4
Appendix A Cont’d
Where an electric security fence passes below bare power line conductors,
the highest metallic element shall be effectively earthed for a distance of not
less than 5m on either side of the crossing point.
This height applies either side of the orthogonal projection of the outermost
conductors of the power line on the ground surface, for a distance of
-
2m for power lines operating at a nominal voltage not exceeding 1 000
V
-
15m for power lines operating at a nominal voltage exceeding 1 000V
Electric security fences and their ancillary equipment shall be installed,
operated and maintained in a manner that minimizes danger to persons, and
reduces the risk of persons receiving an electric shock unless they attempt to
penetrate the physical barrier, or are in a secure area without authority.
Exposed conductive parts of the physical barrier shall be effectively earthed.
A spacing of 2.5 m shall be maintained between uninsulated electric fence
conductors or uninsulated connecting leads supplied from different energizers.
This spacing may be less where conductors or connecting leads are covered
by insulating sleeving, or consist of insulated cables, rated to at least 10kV.
This requirement need not apply where the separately energized conductors
are separated by a physical barrier, which does not have any openings
greater than 50mm.
A vertical separation of not less than 2m shall be maintained between pulsed
conductors fed from different energizers.
Ensure that all ancillary equipment connected to the electric security fence
circuit provides a degree of isolation between the fence circuit and the supply
mains equivalent to that provided by the energiser. Protection from the
weather shall be provided from the ancillary equipment unless this equipment
is certified by the manufacturer as being suitable for use outdoors, and is of a
type with a minimum degree of protection IPX4.
Rev 1.0
