2. GENERAL CLASSIFICATIONS OF ELECTRIC
WORK
• The installation shall be carried out in conformity with the requirements of the
Indian Electricity Act,1910,the Indian Electricity Rules,1956 as amended up to
date,and the Regulation of the Electric Supply Authority concerned.
• The work shall be done according to the specifications described below and is
conformity to the latest issue of the relevant Indian Standards Code of
Practice.
• Only approved material be engineer-incharge shall be used.
• The work,in all cases,shall be started only after the samples have been
approved by the engineer-incharge.The contractor shall have to supply a board
containing samples of all materials,fittingsetc.,if so desired.The board will be
displayed at the site till the completion of work.
• The work shall be carried out under the supervision of a person holding a
certificate of competency issued by the state govt. for the types of works
envolved . the name and other particulars of the person should be submitted
to the engineer incharge before the commencement of the work .
3. GENERAL SPECIFICATIONS
• After completion of errection , the portion of the building , road , land and
other properties damaged during the errection of installation shall be
repaired properly to original finish and colour by contractor .
• All the tests prescribedshall be carried out by the contractor in the
presence of assistant engineer incharge and test results submitted in the
specified performa given in appendix .
• After completion of the work completion certificate submitted by the
contractor sign by the supervisor under whose supervision the work has
been carried out and the contractor in the specified performa
• The contractor shall submit complete wiring diagram of the insulation in
case of internal wiring works , schematic diag. of equipments and
connections for sub station and switch gear works and route layout plans
in cases of over head line and under ground cable on completion of work .
• The wiring diag. shall be submitted on the building plan the branch
distribution board and the branch circuits shall be numbered serially and
indicated on the diagram
• The route layout plan shall be drawn on the site plan of the building
4. SPECIFICATIONS OF INTERNAL
ELECTRIC WIRING
• Definition of a point-A point shall include complete wiring from branch
distribution board to the outlet via switch.The outlet shall be a ceiling rose
in case of ceiling and exhaust fan points,light points for fluorescent tube
fittings and pendant fittings etc.
• Type of wiring-The wiring shall be carried out either on batten with tough
rubber sheathed or P.V.C insulated and P.V.C sheathed cable or in conduit
on surface or concealed in wall with V.I.R or P.V.C insulated wire.
• Layout of wiring-The wiring shall be done on distribution system with
main and branch distribution boards at convenient physical and electrical
load centres and without isolated fuses.
• The balancing of circuits in three phase installations shall be arranged
before hand.
• Medium pressure wiring and associated apparatus shall comply,in all
respects with the requirements of Indian Electricity Rules AcT
5. • Voltage and frequency of supply-All current consuming devices shall be
suitable for the voltage and frequency of the supply to which these are to
be connected
• Cables and flexible cords-The conductors of cables ,except flexible cables
or cords shall be of copper or aluminium as specified.
• Main switches and switch boards – all main switch gear shall be metal
clad and shall be installed in dry condition as near to the point of supply .
• Main and branch distribution board – the main and branch distribution
fused boards shall be of metal clad tile they should be of weather proof
type for exposed to weather and damp situation and flame proof type.
• Wiring of distribution boards – the load coming on distribution board shall
be divided as far as possible evenly between the no. oof ways of the
boards on spare circuit shall be left for future extension .
• Selection of size of conductors – the size of conductors of circuit shall be
so selected thatthe drop in voltage from consumer terminals at any and
every point on the installation does not exceed 3% of the voltage at
consumer terminal
6. SPECIFICATIONS FOR EARTHING
• Earthing shall generally be in accordance with the requirements of indian
electricity rules 1956 as emminded from time to time and revilant
regulations of electricity supply authority concern .
• All earth connections shall be visible for inspection.
• All medium voltage equipments shall be earthed by two separate and
distinct connection through an earthed electrode
• In the case of high and extra high voltages and neutral points shall be
earthed by not less than two separate and distinct connections with earth
each having its own electrode.
• All materials, fittings used in earthing shall confirmed to the Indian
standard specification wherever they exist.
• No earth electrode shall have aohmicresistence greater than five ohms as
measured by an approved by earth testing apparatus.
• Use of plate electrode is recommended only where the current carrying
capacity is prime consideration
7. POINT WIRING
• Point wiring shall include all works necessary for complete wiring of a
• switch circuit of any length from the tapping point on the distribution
• circuit to the following through the switch.
• a) Ceiling rose or connector (in the case of ceiling/exhaust fan point).
• b) Ceiling rose (in the case of pendant except stiff pendant point).
• c) Back plate (in the case of stiff pendants and fittings with down rods)
• d) Socket and Outlets (in the case of socket outlets points)
• e) Lamp Holder (in the case of wall brackets, batten points, bulk head
• and similar fittings).
• f) Call Bell/ Buzzer (in this case the works Via the switch shall be red as
• “ Via ceiling rose, socket outlet or bell push where no ceiling
• rose/socket outlets is provided”)
8. • The following shall be deemed to be included in the point wiring.
• a) Switch.
• b) Ceiling rose or connector as required
• c) Any special and suitable M. S. box for neatly housing the connector
• and covering the fan hook in case of fan point.
• d) Bushed conduit or porcelain where cable pas through walls, floors etc.
• e) Earth wire from the distribution boards to all current carrying
• apparatus through switch boards, M. S. Boxes etc.
• f) All metal blocks, boards, covers and M. S. Boxes, sunk or surface
• mounted including those required for mounting fan regulators but
• excluding those for fixing the distribution switch boards.
• g) All fixing accessories such as clips, nails, screws, phil plug, rawl plug
• etc. as required.
• h) Connection to ceiling rose, connector socket outlets, Lamp holders,
• switch, fan regulator etc.
• i) Looping in the same switch board and inter connections between
9. SUB-MAIN WIRING
• The sub-main wiring shall mean the length of wiring from main
• building panel board/distribution switch board to another
• main/distribution switch board, measured along the run of wiring. Such
• wiring shall be measured on linear basis.
10. SYSTEM OF WIRING
• The wiring shall be carried out as per the system specified in the
tender Schedule.
• Power wiring shall be kept separate and distinct from lighting and fan
wiring.
• All conductors shall run as far as possible along the walls and ceiling so as
to be easily accessible and capableof being thoroughly inspected.
• In all types of wiring due consideration shall be given for neatness, good
appearance and safety.
• The balancing of circuits in 3 wires on poly phase installation shall be
arranged to the satisfaction of Engineer-in-charge.
• In large/important rooms light fans and socket outlet points shall be
distributed over more than one circuit as directed by the Engineer-in-
charge.
11. FLEXIBLE CABLE
• Conductor of flexible cable shall be of copper. The minimum
• permissible size of conductor for flexible cable shall be 16/0.2 mm
• Unless the flexible cables and conduits are protected by armour
• PVC sheaths, these shall not be used in workshops and other places where
they are liable to mechanical damage.
• Three core flexible cables shall be used for connecting single phase
appliance
12. RATING OF LIGHTS,FANS,ETC.
• For the purposes of connected load calculations, incandescent
installations for residential and non residential building shall be rated at
100 W
• Table fans shall be rated at 50/60W. Exhaust fans shall be rated according
to their capacity.
• Amp socket outlet point and 15 Amp socket outlet point shall be rated at
100W and 1000W respectively, unless the actual values of loads are
known or specified.
13. SWITCH BOARDS
• Metal clad switch gear shall be mounted on wall, columns etc. by suitable
mechanical means so as to ensure firm mechanical supports.
• Hinged type boards shall consist of a box made of sheet metal clad,switch
gear, distribution boards etc.
• Hinged metal boards shall consist of a box made of sheet metal of 6 SWG
gauge thick and shall be provided with hinged cover to enable board to be
swung open for the examination of the wiring at the back.
• The joint shall be substantially welded.
• All wires passing through metal boards shall be bushed.
• No apparatus shall project beyond any edge of the panel.
• No fuse body shall be mounted within 2.5 cms of any edge of the panel.
• Fixed type metal boards shall be provided for large switch boards where
number of switch gears and/or higher capacity metal clad switch gears are
to be mounted.
14. MARKING APPARATUS
• When a board is connected to voltage higher
than 250 volts, all the terminals or leads of the
apparatus mounted on it shall be marked in the
following colours to indicate the different poles
or phase to which apparatus or its different
terminals may have been connected.
• Alternating Current:Three phases-Red, Blue,
yellow, Neutral – Black
• Direct Current
• Three Wire System 2 outer
• Neutral - Black
15. CAPACITY OF CIRCUITS
• Lights and fans may be wired on a common
circuit. Such circuit shall not have more than a
total of 8 points of light, fan and socket outlets or
a load of 800 watts, whichever is less.
• The power circuits shall be designed with one
outlet per circuit unless otherwise specified, The
circuits shall be designed based on the loading of
the circuit.
• Where not specified, the load shall be taken as
2000 watts per circuit.
16. TYPE AND SIZE OF CIRCUIT
• Conduit pipe used in wiring system shall be of 16 gauge for sizes upto 32
mm and 14 gauge for sizes above 32 mm.
• Conduit pipes shall be solid drawn or formed by electric resistance
welding (ERW) finished with galvanized or stove enameled surface
• All conduit accessories shall be of thread type.
• Pin grip type or clamp grip type accessories shall not be used.
• The maximum number of PVC insulated 250 volts grade aluminium
conductor cable that can be drawn in one conduit of various sizes is given
in Table I and the number of cables per conduit shall not exceed this.
• Steel conduit of size less than 19 mm in diameter shall not be used
17. CONDUIT JOINTS
• Conduit pipes shall be jointed by means of screwed – screwed accessories
only.
• In long distance straight run of conduit, inspection type completes at
reasonable intervals shall be provided.
• In the latter case the bare threaded portion shall be treated with anti-
corrosive preservative.
• Threads on conduit pipe in all cases shall be between 13 mm to 19 mm
long sufficient to accommodate pipes to full threaded portion of couplers
or accessories.
• Cut ends of conduit pipes shall have no sharp edges nor any burrs left to
avoid damage to the insulation or conductors while pulling them through
such pipes.
• After laying of the conduit the bare threaded portion shall be treated with
• two coats anti-corrosive preservative.
18. FIXING OF CONDUIT
• Conduit run on surface shall be supported on M.S. Spacers 3 mm thick,
painted with 2 coats of anticorrosive primer, which in turn are properly
screwed to the wall or ceiling.
• Rawl plugs or phil plug shall be used for fixing the spacers.
• Conduit pipes shall be fixed on the spacers using C. I. saddles of suitable
size and heavy gauge (SWG).
• Saddles shall be at intervals of not more than 50 cm. Conduit shall be
neatly run parallel or at right angle to the walls of the buildings.
• Saddles shall not be less than 24 gauge for conduit upto 25 mm diameter
and not less than 20 gauge for larger diameter.
• Where conduit pipes are not to be laid along the trusses, steel joints etc.,
the same shall be secured by means of ordinary clips or girder clips as
approved by the Engineer-in-charge.
• Where is not possible to drill holes in the truss members suitable clamps
with bolts and nuts shall be used. The width and the thickness of the
ordinary clips or girder clips and clamps shall be approved by the
Engineer-in-charge.
19. EARTHING OF CONDUIT
• The conduit of each circuit or section shall be completed before
conductors are drawn.
• The entire system of conduit after erection shall be tested for
mechanical and electrical continuity throughout and permanently
specified in earthing system.
• Bare earth wire of size not less than 12 gauge aluminium shall be
run with each conduit and clamped along the run and specifically
across threaded joints using copper earth clamps.
• Gas or water pipe shall not be used as earth medium.
• If conduit pipes are liable to mechanical damage they shall be
adequately protected.
• In a conduit system, pipe must be continuous when passing through
walls or floors.
21. •The flushing cisterns shall be automatic or manually operated
high level or low level as specified, for water closets and urinals.
A high level cistern is intended to operate with minimum height of
125 cm and a low level cistern with a maximum height of 30 cm
between the top of the pan and the under side of the
cistern.
• Cisterns shall be of following type (i) Vitreous China (IS 774) for
Flushing type (ii) Automatic Flushing Cistern (IS 2326) and (iii)
Plastic cisterns (IS 7231).
FLUSHING CISTERNS
22. • The cistern shall be provided with inlet and overflow holes, situated one at each end,
which shall be capable of accommodating overflow pipe of not less than 20 mm nominal
bore and a 15 mm size float valve.
• The holes shall be cleanly moulded or drilled and the adjacent surfaces shall be smooth.
INLET AND OVERFLOW HOLES
Float Valve
• The float valve shall be 15 mm nominal size and shall conform to IS 1703 or IS 12234 or IS
13049.
• Foot rests shall be of Vitreous China conforming to IS 2556 (Part-X). Foot rests which are
rectangular shall meet the minimum requirements and dimensions shown in Fig. 4 and may
be of different designs where so specified. Foot rests of different shapes and sizes shall also
be allowed subject to approval of Engineer-in-Charge.
FOOT RESTS
23. Urinals
Bowl Type Urinals :
• Urinal basins shall be of flat back or corner wall type lipped in front.
•These shall be of white vitreous china conforming to IS 2556-(Part 6).
•The urinals shall of one piece construction. Each urinal shall be provided with not less than two
fixing holes of minimum dia 6.5 mm on each side.
• Each urinal shall have an integral flushing rim of suitable type and inlet or supply horn for
connecting the flush pipe.
•The flushing rim and inlet shall be of the self draining type. It shall have a weep hole at the
flushing inlet of the urinals.
Half Stall Urinals :
•They shall be of white vitreous China conforming to IS 2556 (Part 6).
•They shall be of one piece construction with or without an integral flushing box rim and
provided with slots or alternative fixing arrangement at the flat back end.
•They shall be provided with ridges where integral flushing rim is not provided in the sides of
the interior of the bowl, to divert the water towards the front line of the urinal where
integral flushing box rim is specified, water spreaders provided shall conform to IS 2556 Part-
6 (Fig. 17.13).
•These shall be vitreous China of one piece construction with integral flush inlet. The
tolerance of ± 4 per cent may be allowed on the dimensions specified.
24. The wash basins shall be one of the following patterns and sizes as specified-
(a) Flat back: 660 x 460 mm (Surgeon’s Basin)
630 × 450 mm
550 × 400 mm
450 × 300 mm
(b) Angle back: 600 × 480 mm
400 × 400 mm
WASH BASINS
• Wash basins shall be of white vitreous china conforming to IS 2556 (Part-I) and IS 2556 (Part-4).
•Wash basins either of flat back or angle back as specified shall be of one piece construction,
including a combined overflow.
• All internal angles shall be designed so as to facilitate cleaning. Each basin shall have a rim on
all sides, except sides in contact with the walls and shall have a skirting at the back.
Basins shall be provided with single or double tap holes as specified.
•The tap holes shall be 28 mm square or 30 mm round or 25 mm round for pop up hole. A
suitable tap hole button shall be supplied if one tap hole is not required in installation.
• Each basin shall have circular waste hole to which the interior of basin shall drain.
• The waste hole shall be either rebated or beveled internally with dia meter of 65 mm at top.
• Each basin shall be provided with a non-ferrous 32 mm waste fitting.
25. Wash Down Type (European Type W.C.) :
•Water closets shall be of white vitreous china conforming to IS 2556 (Part-1) and 2556 (Part-2),
as specified and shall be of “Wash down type”.
•The closets shall be of one piece construction.
•Each water closet shall have not less than two holes having a minimum diameter of 6.5 mm for
fixing to floor and shall have an integral flushing rim of suitable type. It shall also have an inlet or
supply horn for connecting the flushing pipe ,the flushing rim may be boxed or open type.
•In the case of box rims adequate number of holes, on each side together with a slot opposite
the inlet shall be provided.
•The flushing rim and inlet shall be of the self draining type. The water closet shall have a weep
hole at the flushing inlet.
•Each water closet shall have an integral trap with either ‘S’ or ‘P’ outlet with at least 50 mm
water seal.
• For P trap, the slope of the outlet shall be 14 deg. below the horizontal. Where required the
water closet shall have an antisiphonage 50 mm dia vent and on either right or left hand or
centre as specified set at an angle of 45 deg. and invert of vent hole not below the central line
of the outlet.
W c
