1. House wiring
Different systems of wiring
The various systems of domestic and industrial wiring are:
1.cleat wiring 2.casing capping 3.c.t.s wiring 4.metal sheeted wiring 5.conduit wiring
Before deciding the type of wiring opt be used at a particular site the following points should be
consider:
a.durability: the wire selected should b able to with stand for a long period against weather changes.
b.Safety: safety is the foremost point to be kept in veiw while making decision of the system of wiring. It
may not prove to be risky. At places, which are not free from fire danger, coundict wiring is preferred
c.cost: the cost of wiring installation is one of the main points to b considered. The system closen should
be economical and with in the needs of indivisual.
d.apperence: wiring apperence has itz own effect. Architectural beauty should b kept in view.
1)cleat wiring: in this system V.I.R wire used bin procelin cleats. The cleats are of three types,haivbin
one,two ro three grooves so as to recive one,two or three wires.they are made in two halves. One Is
grooved to recive the wire while the other is put over it and the whole is fixed on the wall. The system
of installation is cheap n most suitable for temporary wiring. It can b easily installed and also removed
quickly when not require.
2) wood casing capping: the system of wiring recommanded to be made of well seasoned take wood or
any other suitable hard wood. At the top it is covered by a strip known as capping. The width of the
cappin to show the position of the wires so that screws may not be driven through wrong position.
Wood gutties are fixed on the wall seperated by a distance not more than one meter . round porcelin
disc insulators are used between the wood gutties and causing. The fixing is done with counter sunk
scores into the gutties. The capping is screwd over 15cm, for all sized upto 6 cm. width casings.
3)c.t.s wiring: c.t.s cable tyre sheathed wires are availablein single,twin or three cores with acircular or
oval shape.the cable is free from the effects of moisture,acids,alkalies and climatic variations.it can be
exposed to sun.the cable can beburied under/sasonary work but is usually laid over wood battens.the
system is even suitable for places where chemical fumes are present.
4)metal sheathed wiring: the wire consists of rubber-insulated conductor over which a sheath of lead-
aluminium alloy is provided externally.this covering provides protection to the cable frommechanical
injury.in resential buildings they are run over wooden battens.the sheat should be earthed otherwise
electrolytic action may take placedue to lealage of current and therby deteriorate the
covering.moreover,earthing prevents the metal covering from becoming alive.these cabels are not

2. suitable for places where chemical corrision may arise.ther effect on the open ends of cabels are
given;these cabels are more costly than c.t.s ones.
The following points should be notedwhen installing metal-sheathed wiring.
1. Metal clips and saddles used to support the cable should be placed 40cm apar.
2. The supports used should not be of such a material as to cause chemical action with the
sheaths.
3. The leas sheath be properly earthed.
4. The cable should be run over a damp place.
5. The cable should be run incondults when crossing the floor or wall.
6. Sharp bends should be avoided.
5)conduit wiring: workshops and public buildings, this is the most desireable system of wiring it provides
mechanical protection and safety against fire. They can be supported over the wall by saddles n pipe
hooks.
Care and maintenainces of the tools:
1. Pilers: 1) do nut cut steel wires and other hard substances
2. Screw driver:
a)the edge should not be too sharp.
b)this must sit in the slot of the screw head.
c)do not use it as a hammer of a chisel.
3.power:
a) keep it well sharpened
b)do not use it on metals
4.gimlet:
a) it should b kept straight while making holes other wise the screwed portion may damage
5.frimer chisel:
a)always strike chisel with mallet

3. b)grind it on the water stone and sharpen it on the oil stone
6.cold chisel:
a) the edge must b property maintained
b) there should be no trace of oil substance
7.tenon saw or hand x saw:
a)keep the teeth sharp with triaqngular file
b) protect frm rust
c) when not bin use apply Greece
8.drilling machine:
a)keep the machine always clean and fabricate the parts specifically the gears
b)drill bit should be properly fixed in the jaws of the machine
c)keep it perpendicular to the place of the job while making holes
9.soldering iron:
a) before soldring an object first time its bit
b)clean the rust or dirt with a sand paer before applyin the soldring iron
c)soldrting should not be cover heated
10. vice:
a)vice should not b used as anvil
b)it should not be tightened excessively
c)clean regularly after use
11.wiring tools:
1. combination plier
2.side cutting plier
3.long nose piler
4.screwdriver

4. 5.poker
6.gilmet
7.pincer
8.hand drilling machine
9.soldering iron
10.Standard wire guage
11.knife
12.rawl plug tool
ACCESSORIES:
1.I.C.D.P SWITCH 15 amps
2.S.P.T switch 5 amps
3.2-way tuber switch 5 amps
4.intermidiate switch 5amps
5.button holder brass
6.pendent holder
7.slanting or angle holder
8.wall bracket
9.batton holder m.c type
10.wall socket 2pin 5 amps
11.wall socket 3pin 5 amps
12.2pin plug switch combined
13.ceiling rose 5amps
14.3-plate ceiling rose 5 amps

5. 15.junction box or cut out 5 amps
16.electric bell 230 volts and bell push switch
17.bed room transformer 230 volts, 13.5.8 volts
18.s.w.g used for expressing the size of wires
19.kt-kat 15amps
20.c.t.s wire 1/16
21.Flexible wire,plastic or silk core
22.vtr wire 1/18
23.wooden screws 60mm,50mm,no.8 for rectangular
24.wooden screws 30mm no.8 for proclein clets 2ways and 3 ways
25.wooden screws 12mm no.4 for batton holder
26.wooden screws 12mm no.4 for batton holder
27.2 pin socket,wall bracket, transformer and wood capping
28.Proclein alets 2way and 3 way
29.wood batton or reper and bend 15mm, 20mm,12mm etc
30.wood casing and capping
31.link clips 45mm,35mm and 30mm etc
32.nails,12mm no.17 for links clips.
33.bare copper wires no.14 s.w.g
1.EARTHING: in an electric circuit,power passes from positive to the negative terminal. The earth is the
biggest negative terminal. The tendency for current is to pass to the earth if a suitable
contact/conductor is available. In an electric circuit , if there is any gap due to improper connection,
current will not flow in the circuit.but of such a circuit having positive potential is touched by a human
being, current will pass through the body into the earth making him a part of the circuit.
Human body gets electric shock proportional to voltage. Higher the voltage, higher the damage. In
many countries like us, Canada etc the domestic voltage is only 110 v against the 220 v being used in
india. So the danger of shock is prevented in those countries where as we have the problem ,due to 20v
supply voltage.

6. Earthing is a safety device to run an electric conductor in parallel to the circuit connecting body of the
equipment and a third point to the earth. By this in case of any open circuit accidentally, the current
will travel through the earth is illegally necessary for all mechines in factories
Demonstration: earthing system/3-pin plug/ earth connection.
3. Fuse: fuse is a device to protect electrical equipment against overloading of its components
due to short circuits etc. every electrical equipment is designed to with stand certain current
rating . if the current supplied is higher , it will damage the equipment.
To prevent such damage a thin wire of low melting point alloy of optimum current carrying
capacity is near the main switch provided in the circuit exceeds the limit, the fuse wire gets
melted breaking the circuit.this saves the electric equipment from getting spoiled by continues
exposure to such high current.
PRECAUTION: do not use thick wire for fuse as it allows excess current into the circuit and
causes heavy damage permently to equipment
DEMONSTRATION: types of fuse wire/fuse-holder/cartridge/fuse/replacing a fuse.