18-02-2013, 10:27 AM
NATIONAL BUILDING CODE OF INDIA
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SCOPE
This Section covers the essential requirements for
electrical installations in buildings to ensure efficient
use of electricity including safety from fire and shock.
This Section also includes general requirements
relating to lightning protection of buildings.
Exposed Metal — All metal parts of an
installation which areeasily accessible other than:
a) parts separated from live parts by double
insulation;
b) metal name-plates, screw heads, covers, or
plates, which are supported on or attached or
connected to substantial non-conducting
material only in such a manner that they do
not become alive in the event of failure of
insulation of live parts and whose means of
fixing do not come in contact with any internal
metal; and
c) parts which are separated from live parts by
other metal parts which are themselves
earthed or have double insulation.
Conventional Symbols
The architectural symbols that are to be used in all
drawings, wiring plans, etc, for electrical installations
in buildings shall be as given in Annex A.
For other graphical symbols used in electrotechnology,
reference may be made to good practice [8-2(1)].
GENERAL REQUIREMENTS
Conformity with Electricity Act 2003 and Rules
Amended Up-to-date
The installation shall generally be carried out in
conformity with the requirements of The Electrici~
Act, 2003 as amended up-to-date and the Indian
Electrici~ Rules, 1956 framed thereunder and also the
relevant regulations of the Electric Supply Authority
concerned as amended from time to time. Extracts from
the Indian Electricity Rules, 1956, referred to in this
section, are given in Annex B.
Execution of Work
Unless otherwise exempted under the appropriate rule
of the Indian Electrici~ Rules, the work of electrical
installations shall be carried out by a licensed electrical
contractor and under the direct supervision of a person
holding a certificate of competency and by persons
holding a valid permit issued and recognized by any
State government.
General
The design and planning of an electrical wiring
installation involve consideration of all prevailing
conditions, and is usually influenced by the type and
requirement of the consumer. A competent electrical
design engineer should be involved at the planning
stage with a view to providing for an installation that
will prove adequate for its intended purpose, and safe
and efficient in its use. The information given in 3 shall
also be kept in view.
Requirements of Room
1)
2)
3)
The areas given above in respect of the
different categories of rooms holds good
if they are provided with windows and
independent access doors in accordance
with local regulations.
All the rooms shall be provided with
partitions up to the ceiling and shall have
proper ventilation. Special care should
be taken to ventilate the transformer
rooms and where necessary louvers at
lower level and exhaust fans at higher
level shall be provided at suitable
locations.
In order to prevent storm water entering
the transformer and switch rooms
through the soak-pits, the floor level, the
substation shall be at least 15 cm above
Location of Switch Room
In large installations other than where a substation is
provided, a separate switch room shall be provided;
this shall be located as closely as possible to the
electrical load centre preferably near the entrance of
the building on the ground floor or on the first
basement level, and suitable ducts shall be laid with
minimum number of bends from the points of entry
of the main supply cable to the position of the main
switchgear. The switch room shall also be placed in
such a position that rising ducts may readily be
provided therefrom to the upper floors of the building
in one straight vertical run. In larger buildings, more
than one rising duct may be required and then
horizontal ducts may also be required for running
cables from the switch room to the foot of each rising
main. Such cable ducts shall be either be reserved for
the electrical services only or provided with a means
of segregation for medium and low voltage
installations, such as call-bell systems; telephone
installations, fire detection and alarm system,
announcement or public address system. Cables for
essential emergency services such as those related to
fire detection, alarm, announcement should use either
metal conduit in addition to physical segregation from
power cables or use fire survival cables.