SP 30 : 2011

SECTION 19 OFFICE BUILDINGS, SHOPPING AND COMMERCIAL CENTRES

AND INSTITUTIONS
1 SCOPE instruction and education (including
incidental recreation), etc.
This Indian Standard (Part 3/Sec 19) of this Code
covers requirements for electrical installations in NOTE — Larger assembly buildings recreational
occupancies are covered in Part 3/Section 20 of this
office buildings, shopping and commercial centres Code.
and educational and similar institutional buildings.
5 GENERAL CHARACTERISTICS OF
2 REFERENCES
INSTALLATIONS
The Indian Standards given below contain provisions
5.0 General guidelines on the assessment of
which through reference in this text, constitute
characteristics of installations in buildings are
provision of this standard. At the time of publication,
given in Part 1/Section 8 of this Code. For the
the editions indicated were valid. All standards are
purpose of installations falling under the scope of
subject to revision, and parties to agreements based on
this Section the characteristics defined below
this standard are encouraged to investigate the
generally apply.
possibility of applying the most recent editions of the
standards. 5.1 Environment
IS No. Title
The following environmental factors shall apply to
3646 (Part 2) : 1966 Code of practice for interior
office buildings, shopping and commercial centres
illumination: Part 2 Schedule for and educational/institutional buildings.
values of illumination and glare
index Environment Characteristics Remarks
8061 : 1976 Code of practice for design, (1) (2) (3)
installation and maintenance of Presence of Probability of
service lines upto and including water presence of water is
650 V negligible
15707 : 2006 Testing, evaluation, installation Presence of The quantity or
and maintenance of ac electricity foreign solid nature of dust or
meters — Code of practice bodies foreign solid bodies
3 TERMINOLOGY is not significant
For the purpose of this Section, the definitions given
in Part 1/Section 2 of this Code shall apply.
5.2 Utilization
4 CLASSIFICATION
The following aspects of utilization shall apply:
The electrical installations covered in this Section, are
those in buildings intended for the following Utilization Characteristics Remarks
purposes: (1) (2) (3)
a) Office Buildings/Business Buildings — Utilization Characteristics Remarks
These include buildings for the transaction of (1) (2) (3)
business, for the keeping of accounts and conditions of shopping arcades,
records and similar purposes, professional
evacuation etc
establishments, offices, banks, research
establishments, data processing installations, Nature of No significant Small shops
etc. processed of risks
stored
b) Shopping/Commercial Centres/Mercantile
material
Buildings —These include buildings used as
shops, stores, market, for display and sale of Existence of In view of large
merchandise, wholesale or retail, fire risk volume of paper
departmental stores, etc. and furniture, for
example, office
c) Educational Buildings — These include
buildings,
buildings used for schools, colleges and
daycare purposes for more than 8 hours per furniture shops,
week involving assembly of people for etc.
 Environment Characteristics Remarks
(1) (2) (3)
Presence of The quantity and Locations where
SP 30 : 2011 some chemical
corrosive or nature of
polluting corrosive or products are
substances polluting handled in small
quantities, (for engineer on the various aspects of installations design.
substances is not example, From the point of view of the design of the various
significant laboratories in installations, the following shall be considered:
schools and
colleges) will be a) Maximum demand and diversity;
categorized as
b) Type of distribution system, mains and
AF3. For office
and other submains;
buildings covered c) Nature of supply (current, frequency,
by this Section nominal voltages);
situated by the
sea or in d) Prospective short-circuit current at the
industrial zones, supplyintake point;
producing serious e) Division of the installation;
pollution, the
categorization f) Nature of the external influences (see5);
AF2 applies (see g) Maintainability of the installations;
Part 3/Section 8)
h) Nature and details of building services;
Mechanical Impact and
stresses vibration of low 1) Lighting,
severity 2) Air-conditioning, and
Seismic effect Depends on the 3) Lifts.
and lighting location of the j) Other details as relevant such as, pumps for
building fire fighting, lighting, fire-alarm systems,
Capability of Uninstructed A major percentage telephones, call-bells, clock systems, etc;
persons persons of occupants
Children Applies to schools k) Telephone circuits including extensions and
Persons Applies to areas adequately intercom facilities;
such as building advised or m) CCTV for information display and security;
substations and for supervised by n) Computer installation facility where
operating and skilled persons applicable; and
maintenance staff p) Metering system for different loads.
Contact of Persons in non-
NOTE — Fire protection system shall include such
persons conducting
details such as locations of detectors, zonal indicators,
situations central control console, public address system for fire
Conditions of Low density Small offices and fighting, cable runs and their segregation from the other
evacuation occupation, easy shops cable system.
during conditions of q) Parking area
emergency evacuation. A complete drawing of layout of the electrical
High density Departmental installation shall be prepared together with associated
stores occupation, difficult conditions floor plans indicating the details mentioned in (a) to
of evacuation (Q). This wiring diagram shall include outlets for
lights, sockets, bells, ceiling fans, exhaust fans,
location of sectionalized control switches, distribution
High density High rise office boards, etc. In special occupancies such as school or
occupation, commercial centres,
college laboratories, the dc circuits be identifiable in
difficult underground
the layout diagram.( including protective devices like
MCBs,or RCD where ever required. )

6.1 Branch Circuits

6.1.1 The general design of wiring of branch circuits

shall conform to those laid down in Part 1/Section 9
of this Code. However, for special cases such as for
communication networks, fire-alarm system and
6 SUPPLY CHARACTERISTICS AND wiring for data-processing equipment, the
PARAMETERS recommendations of the manufacturer shall apply.

6.0 Exchange of Information 6.1.2 The branch circuit calculations shall be done
according to the general provisions laid down in Part
6.0.1 Proper coordination shall be ensured between 3/ Section 1 of this Code. However, the specific
the architect, building contractor and the electrical demands of the lighting, appliance and motor loads as
 SP 30 : 2011

well as special loads encountered in the types of serve feeders to various load centres, such as air-
buildings covered in this Section shall be taken into conditioning plant, elevators, water pumps, etc. Other
account. loads are taken to local distribution boards.
6.1.3 In offices and showrooms, the interior 6.3.2 The transformer power rating for the supply of
decoration normally include false ceiling, carpets and the building shall be sufficient to cater to the highest
curtails. Any wiring laid above the false ceiling should simultaneous power requirements of the building.
be adequately protected such as by drawing the wires Typical proportions of power usage are given as
in metallic conduits/ GI Cable trays and nor run in follows:
open. Wires shall not be covered by carpets. They Part of Electrical Part of the Total Diversity
shall be run at skirting level and encased for Installation Power Requirement Factor
mechanical protection. Percent
In modern offices cables/wires shall be laid in floor (1) (2) (3)
raceways made of GI/PVC with adequate
Ventilation, heating 45 1.0
compartments alongwith junction boxes/ floor boxes
(air-conditioning)
6.1.4 Adequate number of socket-outlets shall be
Power plant (drives) 5 0.65
provided for electrically operated office machines
Lighting 30 0.95
such as computers, desktop printers,xerox machines
andscanners electrical typewriter, etc, to avoid Lifts 20 1.0
running of wires and use of multiple outlets from one
socket. 6.3.3 The location and layout of building substation
Power circuit ( that is 16A/20A points /sockets and shall conform to the general rules laid down in Part 2
outlets ) should be separate from the lighting circuit of this Code. The substation room shall be well
and protection provided for the same should be ventilated and inaccessible to birds and reasonably
separate ( like MCCBs,/RCD. ) reptile-, rodent- and insect-proof. Only authorized
persons be allowed to enter the substation for
6.1.5 Areas where corrosive or polluting substance are
operations/maintenance of any kind. Cables leading
present intermittently or continuously, such as school
from the substation to the main building shall
laboratories and other buildings located in high
preferably be carried underground through ducts or
industrial pollution zones, socket-outlets shall
pipes of adequate dimensions. Such pipes shall be
preferably be of metal clad weatherproof type with
properly sealed at both ends to reduce the possibility
covers. The cable trays here could be of hot dip
of rain water flowing through the pipes and flooding
galvanized / SS material( suitable IP protection DBs
the trenches.
to be used as per application / surrounding condition
reference ). 6.3.3.1 Buildings should be protected by suitable
lightening and surge protectors/arresters.
6.1.6 Lighting circuits shall preferably be combined in
switched groups so that lighting can be limited to 6.3.4Emergency Supply
desks which are occupied. Each lighting circuit shall
Wherever emergency supply is considered necessary,
be protected by MCBs of suitable rating.
it can be in the form of separate and independent
6.2Service Lines feeder from the undertaking terminated in equipment
The general provisions laid down in IS 8061 shall isolated from the regular supply line. In case of
apply. standby supply from diesel generator set, it will be
installed as per the general rules laid down in Part 2 of
6.3 Building Substations this Code. Automatic transfer switch can be used for
the changeover.
6.3.0General
6.3.4.1 In office buildings, certain safety and essential
The designer of power supply for office buildings and services shall be supplied even in the case of mains
commercial centres shall take into account the great failure. These are governed by the rules and
concentration of power demand of the electrical loads. regulations of the respective authorities. Essential
Air-conditioning in office buildings absorbs an services include amongst others, water-pressure
especially high proportion of the total power used. pumps, ventilation installations, essential lighting and
Consequently, such occupancies have to be provided lifts. also emergency lights on exit door to be installed
with their own substation with vertical and horizontal .The power requirement of these essential loads is
forms of power distribution. generally about 25 percent of the total power
6.3.1 If the load demand is high, requiring supply at requirement of the building.
high voltage, accommodation for substation 6.3.5Switchboards and Panel Boards
equipment will be required. Main switch room will
SP 30 : 2011

All current carrying equipment shall be totally 6.5.1.3Mercantile buildings (Group F)

enclosed, dust-and vermin-proof and if mounted
Besides fire-fighting equipment, automatic sprinkles
outdoor, shall be of weatherproof construction or
and automatic fire alarm systems are recommended
housed in weatherproof kiosk or cabin. Switchboards
for wholesale establishments, warehouses, transport
shall be of open type or cubicle type. Cubicle type
booking agencies, etc, as well as for shopping areas
boards shall be with hinged doors interlocked with
inside buildings with area more than 500 m2 on each
switch-operating mechanisms. All switches shall bear
floor. For other premises and shopping lines with
labels indicating their functions. Switchboards shall
central corridors open to sky, automatic fire-alarm
be located away from areas likely to be crowded by
systems shall be installed. Underground shopping
the public.Suitable IP protected DBs to be use in the
centres shall be provided with automatic sprinkles.
installation.
6.3.6 Selection of equipment shall be made according 6.6 Building Services
to the guidelines laid down in Part 1/Section 16 of this 6.6.1Lighting
Code. For the purposes of office buildings, shopping
and commercial centers, miniature circuit-breakers of 6.6.1.1 The general rules laid down in Part 1/Section
adequate capacity shall be preferred to switch fuse 15 of this Code shall apply. The choice of lamps,
units. They can also be effectively used in place of lighting fittings and general lighting design together
fuses in a distribution board. with power requirement shall be planned based on the
recommended values of illumination and limiting
6.4 Metering values of glare index given in Table 1.Maximum use
In multi-storied buildings, a number of offices and of LED lighting should be preferred for energy
commercial centers occupy various areas. Electrical conservation
load for each of them would have to be metered 6.6.1.2 In commercial premises, a fairly high level of
separately; the meter-room normally is situated in the glare free lighting on working planes and subdued
ground floor (see IS 15707 for further guidance). lighting in circulation areas are necessarywith suitable
protection like MCBs andRCDs . Aesthetics and
6.5 System Protection
interior decoration also play a part. Lighting design in
6.5.0General showrooms includes high level of lighting in the
vertical and horizontal planes, depending on the
The general rules for protection for safety laid down
merchandise exhibited and their layout. Colour
in Part 1/Section 22 of this Code shall apply.
temperature characteristics of the light source shall
Reference is also drawn to SP 7 on guidelines for fire
also be taken into account in the case of showroom
protection of buildings. The general rules given below
lighting.
shall apply.
6.5.1 The type of buildings covered in this Section fell 6.6.1.3 External lighting like street lighting and
under Group B (educational buildings). Group E building façade lighting maybe be connected through
(business buildings) and Group F (mercantile suitable Timers/ Time switches to have auto switching
buildings) from the point of view of fire safety based on time.
classification (see SP 7). Typical firefighting
6.6.2Air-conditioning
installation requirements are also covered therein. The
electrical needs for the appropriate type of installation 6.6.2.1 The general rules laid down in Part 1/Section
shall, therefore, be decided accordingly. 15 of this Code shall apply. The design of the
airconditioning system, shall take into account the
6.5.1.1Educational buildings (Group B)
requirements stipulated in the following clauses.
Educational buildings above 2-storeys having an area
6.6.2.2 Each Split Unit AC shall be wired separately
of more than 500 m2 per floor shall have besides
from the DB with separate MCB for each for short
firefighting equipment, manually operated electrical
circuit and overload protection
fire alarm and automatic fire alarm systems.
6.6.2.3 In case of large air-conditioning installations
6.5.1.2Business buildings (Group E)
(500 tonne and above) it is advisable to have a
Besides fire-fighting equipment, automatic fire alarm separate isolated equipment room together with
systems are recommended for offices, banks, electrical controls. All equipment rooms shall have
professional establishments, parking areaetc, where provision for mechanical ventilation.
the buildings are more than 2 storey with floor area
above 500 m2 per floor, and for laboratories with 6.6.3Lifts and Escalators
delicate instruments as well as computer installations. 6.6.3.1 The general rules laid down in Part 1/ Section
15, of this Code shall apply. However, the design of
 SP 30 : 2011

lifts shall take into account the following

recommendations:
Table 1 Recommended Values of Illumination and Glare Index
(Clause 6.6.1.1)
Sl No. Building Illumination Limiting Glare Index
lux
(1) (2) (3) (4)

i) Banks:
a) Counters, typing ac counting book areas 300 19
b) Public areas 150 19
ii) Libraries:
a) Shelves 70-150 —
b) Reading rooms (newspaper, magazines) 150-300 19
c) Reading tables 300-700 22
d) Book repair and binding 300-700 22
e) Cataloging, sorting, stock rooms 150-300 19
iii) Offices:
a) Entrance halls and reception area 150 —
b) Conference rooms, executive offices 300 19
c) General offices 300 19
d) Business machine operation 450 19
e) Drawing offices 450 16
f) Corridors and lift cars 70 —
g) Stairs 100 —
h) Lift landings 100 —
j) Telephone exchanges;
1) Manual exchange rooms (on desk) 200 16
2) Main distribution frame room 150 25
iv) Schools and colleges:
a) Assembly halls:
1) General 150 16
2) When used for exams 300 16
3) Platforms 300 16
b) Class and lecture rooms: 1)
Desks 300 16
2) Black board 200-300 —
c) Embroidery and sewing rooms 700 10
d) Art rooms 450 16
e) Libraries (seeSl No. ii above.)

f) Manual training [see appropriate trades in IS 3646 (Part 2)]

g) Offices 300 19
h) Staff rooms, common rooms 150 19
j) Corridors 70 —
k) Stairs 100 —
v) Shops and stores1):
a) General areas 150-300 22
b) Stock rooms 1) 200 25

Does not cover display (showroom lighting).

SP 30 : 2011

6.6.3.2Occupant load 6.6.3.3Passenger handling capacity (H)

These shall be as follows: These are expressed in terms of percent of the estimated
population that has to be handled in the building in the 5
Sl Occupancy Occupation min peak period as follows:
No. Load Gross Area
in m2/Person Sl Occupancy H
(1) (2) (3) No. (Percent)
i) Educational 4 (1) (2) (3)

ii) Business 10 a) Diversified (mixed) office occupancy 10-15

iii) Mercantile: b) Single purpose office occupancy 15-25
1) Ground floor and sales 3
2) Upper sale floor 6
with design of the building for daylight use of devices
6.6.3.4Car speed — These shall be as follows: such as automatic light sensors shall be encouraged for
Sl Occupancy No. of Car controlling lighting groups near windows for energy
No. saving.
Floors Speed
Served 20 m/s 8.2 Telephones/Intercoms/Internet
(1) (2) (3) (4)
Adequate coordination shall be ensured right
i) Office building 4-5 0.5-0.75 6-12 fromthe planning stages with the telephone
0.75-1.5
authorities to determine the needs for the telephone
13-20 Above 1.5
system catering to the various units in office
ii) Shops and departmental 2-2.5 buildings. For private intercom systems, entirely
stores under the control of the user, it is necessary to pre-
plan the coordination of external and intercom
systems.Suitable single band or dual band routers to
6.6.3.5 For office buildings, it is desirable to have at be installed depending upon number of users, level
least a battery of 2 lifts at two or more convenient of security and throughput.
points. If this is not possible, it is advisable to have at
least two lifts side by side at the main entrance and
one lift each at different sections of the building for
inter-communication. When two lifts are installed side 8.3 Electric Call Bell System
by side, the machine room shall be suitably planned. 8.3.1 The general guidelines laid down in Part
All machines and switchgear may be housed in one 1/Section 15, regarding installation of electric bells
machine room. and call system shall be referred to. Depending on
the final requirements of the type of occupancy, the
6.6.3.6 Each lift should be protected by an RCD of
type of equipment to be used, wiring and other
30mA sensitivity housed in a separate enclosure
details shall be agreed to.
accessible to Service.
8.3.2 A simple call bell system is suitable for
smalloffices whereby service staff may be called
to a particular position by the caller. A visible-
cum-audible indicator/bell panel shall be used.
7 TESTING OF INSTALLATION When call points are too numerous on a single
indicator panel, such as in large offices, multiple
The various tests on the installation shall be carried
call system shall be preferred. The layout in such a
out as laid down in Part 1/Section 13 of this Code.
case would be determined by the size of building
8 MISCELLANEOUS PROVISIONS and staff. Time bell systems shall be installed in
schools to give Start-work and Stop-work signals
8.1 Group Control (digital programmable time switches can be used
The lighting circuits shall preferably be combinedin where ever required, that is, to start or stop the
switched groups as well as coordinated to functional work).
groups of desks in an open plan office. The switching
points may be combined centrally at the entrance
passageways. In order to ensure proper co-ordination
 SP 30 : 2011

8.4 Clock Systems

8.4.1 The general guidelines contained in Part
1/Section 15 shall apply regarding installation and
maintenance of master and slave clock systems.
8.4.2 In simple installations, impulse clocks
designedto operate at the same current may be
connected in one series circuit, with a battery
having sufficient voltage to ensure satisfactory
operation. In a more complex installation like
multi-storeyed office buildings with large number
of slave clocks, the impulse clocks may be
arranged in number of series circuits. Each of
which is connected to a pair of contact on a relay
which is operated from the contacts of master
clock.
8.4.3 Master clock shall be placed in a dust
freelocation, readily accessible for maintenance at
all times.

8.5 Closed Circuit TV

Commercial buildings may require the installations of
CCTVs for one of more of the following purposes:
a) Security, and safety; or
b) Information display.
Educational/institutional buildings may use CCTV as
a teaching aid for pre-recorded educational programs.
Reference shall be made to good practice for
installations of such facilities.

8.6 Emergency Lights for Critical Areas

Battery powered (at least 2 h rating) emergency lights
should be installed at critical and strategic locations
including emergency exit points. These will provide
illumination by self-contained battery source even on
failure of a.c. mains. On resumption of a.c. power
supply, they will switch back to mains automatically
and simultaneous recharge the battery to the required
level.

8.7 Emergency Exit Lighting / Signage

Emergency lighting units are essential products that
must be fully operational in order to ensure the
safety of people in the event of emergency
evacuation.
These should have LED bulbs and be
capable of remaining ON for at least 2 h during an
emergency and shall have IP42 class of protection.
Photo luminescent safety signage should be
provided at different strategic locations.
.

8 NATIONAL ELECTRICAL CODE