12.5.1 All electric cables should be at least
of a flame-retardant type and should be installed so as not to impair
their original flame retarding properties.
12.5.2 Cables supplying the services listed in 12.3.4 should not pass through high fire risk
areas such as machinery spaces and their casings, etc. except for
those supplying any such services installed in these spaces. Such
cables should not, so far as practicable, be run on bulkheads or deck
where a fire in an adjacent space would render the cables unserviceable.
12.5.3 Except as permitted by the Administration
in exceptional circumstances, all metal sheaths and armour of cables
should be electrically continuous and should be earthed (grounded).
12.5.4 All cables should be efficiently supported
in such a manner as to avoid chafing or other injury.
12.5.5 Terminations of and joints in cables should
be made in junction boxes. The Administration may accept other arrangements
provided that they retain the original mechanical, fire retarding
and electrical properties of the cable.
12.5.6 Where cables are installed in fire- or
explosion-hazardous areas, special precautions should be taken to
the satisfaction of the Administration to preclude the possibility
of fire or explosion due to faults of cables.
12.5.7 Distribution systems should be so arranged
that the feeders from the main and emergency sources, passing through
a fire hazard area, are separated both vertically and horizontally
as widely as is practicable.
12.5.8 Cross-sectional areas of cables and wires
should be chosen according to permissible electrical loads and rated
operating temperatures taking into account the ambient temperatures
which may be experienced in the proposed areas of operation. The choice
of the cross-sectional areas of low-loaded wires should also take
into account the necessary mechanical strength where materials other
than copper are used for conductors. The Administration should be
satisfied as to their suitability having regard to the marine environment.
12.5.9 All essential services should be supplied
by separate and individually protected circuits.
12.5.10 All circuits should be protected against
short circuit and overload except as referred to in 12.6.1. So far as is practicable, the circuit
protective devices should be co-ordinated so that only the circuit
affected by the overload or short circuit will be removed from service.