12.8.1 All electrical equipment should be so designed,
constructed and installed that it is suitable for any voltage which
may be supplied to it and does not constitute any danger or cause
injury to personnel under normal operation conditions.
12.8.2 Effective means should be provided so that
power may be shut from each and every circuit and sub-circuit as may
be necessary to prevent danger.
12.8.3 Electrical equipment should be so designed
that the possibility of accidentally touching live parts, rotating
or moving parts as well as heated surfaces which might cause burns
or initiate fire is minimized.
12.8.4 Electrical equipment should be adequately
secured. The probability of fire or dangerous consequences arising
from damage to electrical equipment should be reduced to an acceptable
minimum.
12.8.5 All exposed metal parts of electrical equipment
which are not intended to be "live", but which are liable under fault
conditions to become "live" should be earthed (grounded) unless:
The Administration may require the earthing of electrical equipment
specified in sub-paragraphs (a) and (b) above as well as portable
equipment, if it is installed or intended for use in exceptionally
damp spaces.
12.8.6 Main and emergency switchboards should
be so designed and installed as to give easy access to apparatus and
equipment arranged inside the switchboards. The sides, backs and fronts
of switchboards should be suitably guarded. Exposed live parts having
voltages to earth (ground) exceeding 55 volt should not be installed
on the front of such switchboards. There should be non-conducting
mats or gratings at the switchboard fronts where necessary and practicable.
Switchboards operating on voltages in excess of 55 volt should have
a suitable notice warning persons working on the equipment of the
hazard.
12.8.7 The rating or appropriate setting of the
overload protective device for each circuit should be permanently
indicated at the location of the protection device on the switchboard.
12.8.8 Lighting fittings should be so arranged
as to prevent the wiring and other surrounding materials from becoming
excessively hot.
12.8.9 In all spaces where flammable mixtures
are liable to collect, no electrical equipment should be installed
unless the Administration is satisfied that it is:
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(a) essential for operational purposes;
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(b) appropriate to the space concerned; and
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(c) appropriately certified for safe usage in
the dusts, vapours or gases likely to be encountered in the process
of operation.
12.8.10 Accumulator batteries should be suitably
housed, and compartments used for their accommodation should be properly
constructed and efficiently ventilated. Starting accumulator batteries
of main and auxiliary engines may be arranged in machinery spaces
in gas-tight boxes ventilated separately to the open air. Where the
starting batteries are arranged according to 12.3.1
and 12.3.2 and have additional capacity satisfying the requirements
of 12.3.4 and 12.3.5, the Administration
may in special cases permit that these starting batteries be used
as emergency power source required by 12.3.1.
In these special cases arrangements shall be such that under normal
operations the batteries cannot be discharged to a point where the
load and time period requirements specified in 12.3 cannot be assured.
12.8.11 Electrical and other equipment which may
constitute a source of ignition of flammable vapours should not be
permitted in the accumulator battery spaces.