survey report on house wiring

1

Submitted To: Submitted By:

Neetika Arora Chandan Garg (2011/71)

Deepak Singla (2011/43)

Manjinder Singh (2011/79)

Shubham Dani (2010/65)

Kulwinder Singh (2010/46)

SURVEY REPORT

3

1. Introduction............................................................................7

2. Topics.....................................................................................9

3. Switches................................................................................11

3.1. Types of Switches (Rating).............................................13

3.2. Types of Switches (Operation)........................................15

3.3. Comparison of Various Types of Switches......................17

4. Sockets..................................................................................19

4.1. Types of Sockets.............................................................21

4.2. Comparison of Various Types of Sockets........................27

5. Plugs......................................................................................29

5.1. Types of Plugs................................................................29

5.2. Comparison of Various Types of Plugs............................31

6. Lamp Holder.........................................................................33

6.1. Types of Lamp Holder....................................................35

6.2. Comparison of Various Types of Lamp Holder................37

7. Support Modules....................................................................39

7.1. Various Support Modules................................................39

7.2. Comparison of Various Types of Support Modules..........47

8. House Wiring.........................................................................49

8.1. Factor Affecting The Choice of Wiring...........................49

8.2. Types of Wiring System..................................................51

8.2.1. Cleat wiring System..............................................53

8.2.2. CTS wiring System...............................................57

8.2.3. Metal or lead sheathed wiring System.....................59

8.2.4. Casing and Capping Wiring System........................61

Index

5

8.2.5. Conduit wiring System........................................63

8.2.6. Specification of Wires.........................................65

9. References...........................................................................67

9.1. Visiting Shops..............................................................69

9.2. Websites.......................................................................71

7

SURVEY REPORT means analysis of different

things of different company. Our topic on the survey is “Material

required in house wiring”. In survey, we concentrate mainly on

switches, sockets, conduit metal boxes, and wires. We visit the various

electrical shops and collect data in catalogues. In this report, we

compare them based on their ratings, standard packing, and prices.

Different company Havells, Anchor, Riyo, Fine etc. are taken for

comparison. Its help us to select that which brand is best with respect

to other brands in all aspects either economically or on the quality

basis. One purpose of market survey is also keep up-to-date about the

developments in all products. By the market survey, one can easily

make estimate about the total approximate cost of any project

beforehand. So Market Survey play an integral role for an Electrical

Engineer.

Introduction

9

To study various types of domestic wiring components such as:

Switches

Sockets

Plugs

Lamp holders

Support Modules

Cables

Topics

10

Switch

11

A switch is a device used for making and breaking the

electrical connection, hence allowing the current to be flow in required

durations. An important device is used in the house wiring. It is applied

in every electrical connection. There are many types of switches such

as:-

Mechanical Switch.

Electro-Mechanical Switch.

Electronic Switch.

The main function of switch is to perform ON and

OFF operations. In the electro-mechanical switch, there may be two or

three terminals depending upon application. This type of switch is

controlled manually, i.e. just by pressing it. This type of switch is most

widely today. Contacts of switch are connected to an external circuit.

Each set of contacts can be in one of two states either ‘closed’ meaning

the contacts are separate or the switches are non-conducting. The

mechanism actuating the transition between two states can be either is

toggle type.

Switches

12

I. One-Way Switch

II. Two-Way Switch

III. Bell Push Button

13

Based on operation, they are mainly of three types, which are as

follow:

I. One-Way Switch: It is a two terminal switch. It is preferred to be

connected in the phase wire. One terminal is connected to the

supply and other to the one terminal of the appliance. It is

connected almost to the every apparatus.

II. Two-Way Switch: It is a three terminal switch. It is always used

in a group of two to operate one appliance from two different

places any time. Two-end terminal of both the switches are short-

circuited side by side. Middle terminal of one switch is connected

to supply and of other is connected to one terminal of appliance.

We mostly use this switch in stairs.

III. Bell Push Button: It is a one-way switch with a spring controlled.

It always connects in phase wire. It is used in bell connection.

14

I. 6A Switch

II. 16A Switch

III. 32A DP Switch

15

Based on rating, they are mainly of three types, which are as follow:

I. 6A Switch: This switch is applied in the circuits containing the

current less than 6A. If the current exceeds the value of 6A then

terminal of switch starts burning. It is connected in house wiring

system to control the current lamp, TV, Fans etc.

II. 16A Switch: This switch is connected where the circuits

containing current more than 6A but less than 16A. If the current

exceeds the value of 16A then terminal of switch starts burning. It

is connected in house wiring system to control the major

appliances like water pumping motor, geyser etc.

III. 32A DP Switch: This switch is a four terminal switch or a

combination of two switches. Two terminals are connected to the

mains supply and two to the bus bar of domestic wiring. This

switch is connected in between the mains supply and bus bar of

domestic wiring.

Ratings of Single/Two/Push Way Switches:

1. 6A / 240V / 50Hz

2. 20A / 240V / 50Hz

3. 25A / 240V / 50Hz

4. 32A / 240V / 50Hz

17

S. No. Company Name Code Standard pkg. Price(Rs)/Unit

1.

6A Single Way Switch

Havells AHCSXXW101/06 20 104/-

Anchor Deluxe 14111/95111 30 20/-

Cherry 14121/95121 30 21/-

Riyo R-001 20 33/-

Fine(Modular) 161 20 50/-

2.

6A Two Way Switch

Havells AHCSXXW102/06 20 140/-

Anchor Deluxe 14112/95112 30 27/-

Cherry 14122/95122 30 28/-

Riyo R-002 20 42/-


3.

6A Bell Push Switch

Havells AHCSBXW100/06 20 150/-

Anchor Deluxe 14112/95112 30 27/-

Cherry 14122/95122 30 28/-

Riyo R-003 20 42/-


4.

16A Single Way Switch

Havells AHCSXXW161 20 158/-

Anchor 14401/95401 10 81/-

Riyo R-004 20 50/-


5.

16A Two Way Switch

Havells AHCSXXW162 20 192/-

Anchor 14402/95402 10 97/-

Riyo R-006 20 62/-


6.

32A DP Switch With Indicator

Havells AHCSDIW321 10 480/-

Anchor 14404/95404 10 142/-

Riyo R-021 10 150/-

Fine(Classic) 416 10 150/-

COMPARISON OF VARIOUS TYPE OF SWITCHES

18

Socket

19

A power socket is a device to which electrical

devices can be connected to receive the electric current required for

their operation. Connected by a system of cables to a power source,

usually an electricity generation facility operated by an energy

production company, it generally has no moving parts. Instead, it

contains metal strips which make contact with the prongs of an electric

plug inserted into the socket. It’s through these contacts that the electric

current is transmitted.

Electrical devices which connect to a power

source through a power socket are considered to be portable because

they can easily be connected and disconnected from the power source.

Portable electric devices have a length of cable terminating in a two,

three or four prong plug. The prongs are shaped like blades or

cylinders, and may be a combination of the two. When a plug is inserted

into a power socket, a circuit is completed. Every power socket thus

needs at least two slots one with a live or “hot” contact strip to transmit

current to the device being plugged in, and one to return the current.

Sockets

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I. 2 Pin Socket

II. 3 Pin Socket

III.5 Pin Socket

21

TYPES OF SOCKETS

I. 2-Pin Socket: As the name implies, it consists of two pins or

holes in which 2-pin plug is inserted. It is mainly used in case of

light load. Its contacts are made of copper alloys. These are made

of different shapes. These are used for small loads.

Ratings: 6A / 240V / 50Hz.

II. 3-Pin Socket: From its name, it is cleared that it consists of three

pins or holes in which 3-pin plugs are inserted. These are better

than 2-pin socket from safety point of view. Because it has three

pins. The third pin has greater diameter as compared to two other

pins. It is used for earthing purpose. Diameter of third pin is

increase in order to decrease resistance. In case of fault, it may

be short circuited, then under such condition , this pin provide

low resistance path to short circuit current and hence provides

better safety to operator.

Ratings of 3-pin socket:

1. 6A / 240V / 50Hz

2. 10A / 240V / 50Hz

3. 16A / 240V / 50Hz.

III. 5 Pin Socket: From its name , it is cleared that it consist of 5

pins or hole, into which in which 3 pin or 2 pin plugs are

inserted. It is a combination of 2-pins or 3-pins according to

requirement. These type of sockets are most widely used.

22

Multi-Pin Socket

23

Today, we can use many auxiliaries by using single 5-pin

socket.

Ratings of 5-pin socket:

1. 6A / 240V / 50Hz

2. 10A / 240V / 50Hz

3. 16A / 240V / 50Hz

IV. Multi-Pin Socket: With the multi socket, we can connect no. of

appliances having different type of plug of any pin type by same

switch. We can control all the appliances connected to multi

socket just by one switch. This socket is also known as

UNIVERSAL SOCKET.

Ratings of Multi Sockets:

1. 6A / 240V / 50Hz

2. 10A / 240V / 50Hz

3. 16A / 240V / 50Hz

24

Round Type Extension Board

25

V. Round Type Extension Board: It is simply a board consists of

many sockets. Sometimes, we have to extent electrical

connection for temporary purpose. There we use this type of

socket. From the name, it indicates that it may be of round or

rectangular shape and the wire is wounds on the periphery

provided inside the cord. An indicator is also connected near

the sockets, which shows the presence of supply. Sometimes a

fuse is also connected for safety of the operator and appliances

to eliminate the fault.

Ratings of Extension Boards:

6A / 240V / 50Hz

27

S. No. Company Name Code Standard Pkg. Price(Rs)/Unit

1.

6A 2 Pin Socket

Havells AHLKSXW062 20 106/-

Anchor 14301/95301 20 25/-

Riyo R-009 20 42/-

Fine(Modular) 168 20 54

2.

6A 3 Pin Socket

Havells AHLKPXW063 10 150/-

Anchor 14302/95302 10 33/-


3.

6A 5 Pin Socket


Anchor 14304/95304 20 33/-

Riyo R-010 20 47/-


4.

Universal Socket


Anchor 14307/95307 10 84/-

Riyo R-013 10 100/-


5.

4 Steps Fan Regulator

Havells AHLRFXW004 20 520/-

Anchor 14501/95501 10 232/-

Riyo R-017 10 155/-


6.

5 Steps Fan Regulator

Havells AHLRFHW005 10 580/-

Anchor 14502/95502 10 261/-

Riyo R-018 10 180/-


COMPARISON OF VARIOUS TYPE OF SOCKETS

28

2-Pin Plug

3-Pin Triangular Plug

29

An AC power plug is a portable electrical

connector which consists at the minimum of two metal contact prongs

designed to make contact with matching points connected to a power

supply, usually contained in a protected electrical outlet. Except for the

actual metal contacts, an AC power plug is protected by an insulated

grip that's designed for ease of insertion into, or extraction from, a

power outlet. Power is transmitted from the plug to the device by means

of an insulated cable.

AC power plugs, and the outlets they plug

into, conform to the electrical codes of the nation they're located in,

which vary greatly from one nation to another, and considerable debate

exists as to the efficacy of each. They all have at least two prongs one,

called “live” or “hot,” and a second prong, usually called “neutral” or

“cold.” Many have a third prong, which conducts current only in the

case of insulation failure in the device. These prongs fit into the slots

on the electrical outlet and make contact with metal elements inside the

outlet that are wired into corresponding components of the electrical

system.

Types of Plugs:

1. 2-Pin 6A / 240V

2. 2-Pin 16A / 240V

3. 3-Pin Triangular pin 6A / 240V

4. 3-Pin Triangular Plug 16A / 240V

Plugs

31

S No. ITEMS HAVELLS LEGEND FINE

1. 2-Pin Plug

6A / 240V / 50Hz. 45.00 23.00 22.50

2. 2-Pin Plug

16A / 240V / 50Hz. 55.00 27.00 28.00

3. 3-Pin Plug

6A / 240V / 50Hz. 60.00 31.00 31.00

4. 3-Pin Plug

16A / 240V / 50Hz 80.00 46.00 56.00

COMPARISON OF VARIOUS TYPE OF PLUGS

32

Lamp Holder

33

Light bulbs are inserted in Light Bulb

Sockets usually known as Lamp Holders, which provide electrical

connections to the bulb and support it in the lighting fixture. At the end

of life of bulb, to change power, colour, lighting technology etc., the

use of lamp holders allows the lamps to be change safely and

conveniently. There are many different standards for these sockets,

created by de facto and by various standards bodies. A general coding

system is a letter or abbreviation followed by a number. Some

miniature lamps have wire leads suitable for direct connection to wires;

some reflector lamps have screw terminals for wire connections.

The function of Lamp Holder is to support Lamp and to

connect it electrically to the supply terminals. Generally, lamp holders

are made of Bakelite with solid Brass plungers, which touch with the

cap of lamp that is made of Brass with Porcelain insulation between

two Brass plungers. Brass holders are most durable but may give a

shock in case the connections are loose. The switch controls the lamp

holders. These are of different type or sizes of lamps are available in

circuits for the connection of different type of lamp we use different

type of lamp holders.

Lamp Holder

34

Batten Lamp Holder

Angled Lamp Holder

Pendant Lamp Holder

35

TYPES OF LAMP HOLDERS

I. Batten Holders: There are variety of batten type lamp holders in

the market such as:-

A. Straight Batten Lamp Holder Fitted With A ‘Short Shied’:

This shield provides protection against touching of lamp cap.

The batten holder has no back plate and hence it cannot be

mounted directly on a surface without use of a box or base.

Batten Lamp Holders may have two or three terminals present.

B. Angle Lamp Holder: These type of lamp holders available in

short and long shield. The long shield provides better

protection against touching of lamp. They have limited use in

a modern installation.

II. Pendant Lamp Holder: This type of lamp holder is used where

pendant or hanging type lightning is required. Electrical structure

or same function as compared to other lamp holder but

mechanically, there is a change as compared to other lamp

holders. At a time, there is only one lamp can placed or fit in it.

Ratings of Lamps Inserted In It:

1. 100W, 200W, 40W Lamp / 220V / 50 Hz

2. 15 W, 18 W, 40 W CFL / 220 V / 50 Hz

37

S No. ITEMS HAVELLS LEGEND SSK

1. Batten Lamp Holder 50.00 20.00 25.00

2. Jumbo Batten Lamp Holder 60.00 35.00 35.00

3. Angle Lamp Holder 60.00 20.00 30.00

4. Pendent Lamp Holder 45.00 25.00 25.00

COMPARISON OF VAROIUS TYPE OF LAMP HOLDER

38

4-Steps Fan Regulator

5-Steps Fan Regulator

Lamp Dimmer

39

In our daily life, we use another support

modules in the switch boards like fan regulator, Lamp Dimmer,

Telephone jack, TV outlet and LAN outlet.

Various Support Modules:

I. Fan Regulator: In order to control or regulate the speed of the

Fan, Fan Regulator is used. There are many type of fan regulators

are available in the market like Electronic Fan Regulator is most

widely used today. By using them, we can control the speed of fan

in steps. Its size is almost equal to other domestic auxiliaries like

switch or simple electrical socket.

II. Lamp Dimmer: Dimmers are devices used to vary the brightness

of a light. By decreasing or increasing the RMS voltage and,

hence, the mean power to the lamp, it is possible to vary the

intensity of the light output. Although variable-voltage devices are

used for various purposes, the term dimmer is generally reserved

for those intended to control light output from resistive

incandescent, halogen, and (more recently) compact fluorescent

lights (CFLs) and light-emitting diodes (LEDs). More specialized

equipment is needed to dim fluorescent, mercury vapor, solid state

and other arc lighting.

Dimmers range in size from small units the

size of a light switch used for domestic lighting to high power

units used in large theatre or architectural lighting installations.

Small domestic dimmers are generally directly controlled,

although remote control systems (such as X10) are available.

Support Modules

40

TV Outlet

Telephone Jack

Lamp Indicator

41

Modern professional dimmers are generally controlled by a digital

control system like DMX or DALI. In newer systems, these

protocols are often used in conjunction with Ethernet.

III. TV Outlet: This provides the accommodation for the aerial

connection. This is installed in the switchboard. In case of

concealed conduit wiring, this type of outlet cannot project out of

the surface. On this outlet, one end of the flexible cable is

connected. Whereas the other end of that wire is connected to the

TV.

IV. Telephone Jack: It is another outlet which is installed in switch

board in order to provide the connection to Telephone. Normally

RJ-45 jack is used for this purpose. Its size is almost equal to the

single or two way switches. One or more points are available in a

single jack.

V. Indicator: The purpose of the indicator is to show the presence of

electricity. Mostly Red color indicator is used. Depending upon

the quality and type of light used, its price may vary. This

indicator is mostly turn ON at all the times, so it should be such

that it consume less power.

VI. Cover Plates: Whether looking for classic western look. Cover

Plates covers the whole sets of switches and sockets. These plates

provides extra ordinary look to your house. These plates are made

of insulating material mostly P.V.C (Poly Vinyl Chloride) is used.

They do not have any electrical connection with wiring they just

provide pleasant look. Different manufactures made different

types of cover plates. According to the no. of switches and

sockets, these are made of different types and sizes.

42

One Module Cover Plates

Two Module Cover Plates

Three Module Cover Plates

Four Module Cover Plates

43

Different Types of Cover Plates:

a) One-Module: In the domestic wiring where one switch is used,

this cover plate is used. For different types or sizes of switches

depend upon their manufacturer’s plates are made of different

sizes.

b) Two-Module: In the domestic wiring where two switch is

used, this cover plate is used. For different types or sizes of

switches depend upon their manufacturer’s plates are made of

different sizes.

c) Three-Module: In the domestic wiring where three switch is



different sizes.

d) Four-Module: In the domestic wiring where four switch is



different sizes.

e) Six-Module: In the domestic wiring where six switch is used,

this cover plate is used. For different types or sizes of switches

depend upon their manufacturer’s plates are made of different

sizes.

f) Eight-Module: In the domestic wiring where eight switch is



different sizes.

g) Twelve-Module: In the domestic wiring where twelve switch

is used, this cover plate is used. For different types or sizes of


different sizes.

45

h) Multi-Module: In the domestic wiring where many or no. of

switch is used, this cover plate is used. These points may be

consist of switches, sockets for indicator etc. because in

domestic wiring, according to the requirements no. of points

are different at different places, so to overcome this problem

we use multi-module cover plate. Multi-Module are of

different sizes or shape.

47

S. No. Company Name Code Standard Pkg. Price(Rs.)/Unit

1.

TV Socket

Havells AHOKTOW061 20 148/-

Anchor 14607/95607 10 39/-

Riyo R-014 20 50/-

Fine(Goldline) 817 20 87/-

2.

Indicator Lamp

Havells AHOIXIW061 20 95/-

Anchor 14601/95601 20 34/-

Riyo P-006 20 45/-


3.

Lamp Dimmer

Havells AHODEXW040 10 590/-

Anchor 14504/95504 10 205/-

Riyo R-016 10 125/-

4.

RJ-45 Jack

Havells AHOKJWW451 20 650/-

Riyo M-015A 10 230/-


5.

RJ-11 Telephone Jack

Havells AHOKROW061 20 148/-

Anchor 14603/95603 20 75/-

Riyo R-015 20 58/-


Cover Plates

S.NO. Items Havells Gold Medal Fine

1. One-Module 78 58 48

2. Two-Module 82 58 48

3. Three-Module 92 69 62

4. Four-Module 125 8 74

5. Six-Module 155 108 128

6. Eight-Module 188 137 185

7. Twelve-Module 225 172 213

8. Multi-Module 285 222 226

COMPARISON OF VAROIUS TYPES OF SUPPORT MODULES

48

House Wiring

49

Electrical wiring is generally refers to

insulated conductor used to carry current and associated device. This

article describes general aspects of electrical wiring as used to provide

power in buildings and structures, commonly referred to as building

wiring.

Types of wiring according to uses

1. Domestic wiring

2. Commercial wiring

3. Industrial wiring

FACTOR AFFECTING THE CHOICE OF WIRING

1. Durability: Type of wiring selected should conform to standard

specifications, so that it is durable i.e. without being affected by the

weather conditions, fumes etc.

2. Safety: The wiring must provide safety against leakage, shock and

fire hazards for the operating personnel.

3. Appearance: Electrical wiring should give an aesthetic appeal to

the interiors.

4. Cost: It should not be prohibitively expensive.

5. Accessibility: The switches and plug points provided should be

easily accessible. There must be provision for further extension of

the wiring system, if necessary.

6. Maintenance Cost: The maintenance cost should be a minimum.

House Wiring

51

Types of Wiring System

Cleat Wiring System

CTS wiring or TRS wiring or batten wiring System

Metal or lead sheathed wiring System

Casing and capping System

Conduit wiring System

52

Cleat Wiring System

53

Cleat Wiring System

This System uses insulated Cables sub-

protected in porcelain cleats. CLEAT WIRING SYSTEM is

recommended for temporary installations. The cleats are made in pairs

having bottom and top halves. The bottom half is groove to receive the

wire and the top half is for cable grip. Initially the bottom and top cleats

are fixed on the wall loosely according to the layout. Then the cable is

drawn, tensioned and the screw tightens the cleats. Cleats are of three

types, having one, two, or three grooves, to receive one, two, or three

wires.

CLEAT WIRING SYSTEM is one of the

cheapest wiring considering the initial cost and labour, and is most

suitable for temporary wiring. In this system, wires can be quickly

install, easily inspected, and altered. When not required, this wiring

system can be easily dismantle without any damage to the cables,

cleats, and accessories.

All cleats are consist of two parts a base piece

and a cap. Cleats are might be fixed at the distance not more than 60

cm apart and at regular intervals.

Where CLEAT WIRING SYSTEM is laid

along the iron joist, porcelain cleats either be inserted with varnished

wood fillets or varnished wood clamps securely fixed to prevent the

conductors from coming in contact with the metal along witch they are

passing.

55

Fixing of Cleats: In ordinary cases, cleats are might be attached to

wooden plugs fixed to the walls.

Distance Apart of Wires: For pressure up to 250 volts, cleats shall be

of such dimensions that in the case of branch loads, conductors shall

not be less than 2.5 cm apart, centre to centre, and in the case of sub-

mains not less than 4 cm apart, centre to centre. Care must be taken in

selecting the size of cleats particularly for branch distribution wiring

where two-way and three-way porcelain cleats are essential and the

difference in size shall be reasonable. Care should also be taken ensure

that grooves f porcelain cleats are essential and the difference in size

shall be reasonable. Care should also be taken ensure that grooves of

porcelain cleats do not compress the insulation nor be too wide for a

loose fit. Under no circumstances, two wires can be place in one groove

of the porcelain cleats.

Advantages

1) Easy installation.

2) Materials can be retrieve for reuse.

3) Flexibility provided for inspection, modifications, and expansion.

4) Relatively economical.

5) Skilled labour is not required.

Disadvantages

1) Appearance is not good.

2) Open system of wiring requiring regular cleaning.

3) Higher risk of mechanical injury.

56

CTS Wiring System

57

CTS Wiring System

In this wiring system, wires were sheathed in

tough rubber are used which are quite flexible. They are clip on wooden

battens with brass clips (link or joint) and fixed on to the walls or

ceilings by flat head screws. These cables are moisture and chemical

proof. They are suitable for damp climate but not suitable for outdoor

use in sunlight. TRS WIRING SYSTEM is suitable for lighting in low

voltage installations.

Advantages

1. Easy installation and is durable

2. Lower risk of short circuit.

3. Cheaper than casing and capping system of wiring

4. Gives a good appearance if properly erected.

Disadvantages

1. Danger of mechanical injury.

2. Danger of fire hazard.

3. Should not be expose to direct sunlight.

4. Skilled workers are required.

58

Metal or Lead Sheathed wiring System

59

Metal or Lead Sheathed Wiring System

This wiring system is similar to that of CTS

WIRING SYSTEM but the conductors (two or three) are individually

covered or insulated with a common outer lead-aluminium alloy

sheath. The sheath protects the cable against dampness, atmospheric

extremities, and mechanical damages. The sheath is earthed at every

junction to provide a path to ground for the leakage current. They are

fix by means of metal clips on wooden battens. The wiring system is

very expensive. It is suitable for low voltage installations.

Precautions To Be Taken During Installation:

1. The clips used to fix the cables on battens should not react with the

sheath.

2. Lead sheath should be properly earthed to prevent shocks due to

leakage currents.

3. Cables should not be run in damp places and in areas where

chemicals (may react with the lead) are used.

Advantages

1. Easy installation and is aesthetic in appearance.

2. Highly durable.

3. Suitable in adverse climatic conditions provided the joints are not

exposed.

Disadvantages

1. Requires skilled labour.

2. Very expensive.

3. Unsuitable for chemical industries.

60

Casing and Capping System

61

Casing and Capping System

This wiring system consists of insulated

conductors laid inside rectangular, teakwood or PVC boxes having

grooves inside it. A rectangular strip of wood called capping having

same width as that of casing is fixed over it. Both the CASING and the

CAPPING are screwed together at every 15 cm. Casing is attached to

the wall. Two or more wires of same polarity are drawn through

different grooves. The system is suitable for indoor and domestic

installations.

Advantages

1. Cheaper than lead sheathed and conduit wiring.

2. Provides good isolation, as the conductors are place apart reducing

the risk of short circuit.

3. Easily accessible for inspection and repairs.

4. Since the wires are not expose to atmosphere, insulation is less

affected by dust, dirt, and climatic variations.

Disadvantages

1. Highly inflammable.

2. Termites damage usage of unseasoned wood.

3. Skilled workmanship required.

62

Conduit Wiring System

63

Conduit Wiring System

In this system, PVC (polyvinyl chloride) or

VIR cables are passes through metallic or PVC pipes providing good

protection against mechanical injury and fire due to short circuit. They

are either embedded inside the walls or supported over the walls, and

are known as concealed wiring or surface conduit wiring (open

conduit) respectively. The conduits are buried inside the walls on

wooden gutties and the wires are drawn through them with fish (steel)

wires. The system is best suited for public buildings, industries, and

workshops.

Advantages

1. No risk of fire and good protection against mechanical injury.

2. The lead and return wires can be carry in the same tube.

3. Earthing and continuity is assured.

4. Waterproof and trouble shooting is easy.

5. Shock- proof with proper earthing and bonding

6. Durable and maintenance free

7. Aesthetic in appearance

Disadvantages

1. Very expensive system of wiring.

2. Requires good skilled workmanship.

3. Erection is quiet complicated and is time consuming.

4. Risk of short circuit under wet conditions (due to condensation of

water in tubes).

64

Wires Used in House Wiring

65

Specification of Wires

The conductor material, insulation, size and

the number of cores, specifies the electrical wires. These are important

parameters as they determine the current and voltage handling

capability of the wires. The conductors are usually of either copper or

aluminium. Various insulating materials like PVC, TRS, and VIR are

used. The wires may be of single strand or multi strand. Wires with

combination of different diameters and the number of cores or strands

are available.

Example: The VIR conductors are specifies as 1/20, 3/22, 7/20.

The numerator indicates the number of

strands while the denominator corresponds to the diameter of the wire

in SWG (Standard Wire Gauge). SWG 20 corresponds to a wire of

diameter 0.914mm, while SWG 22 corresponds to a wire of diameter

0.737 mm. A 7/0 wire means, it is a 7-cored wire of diameter 12.7mm

(0.5 inch). The selection of the wire is depending on the requirement

considering factors like current and voltage ratings, cost and

application.

Example: Application: domestic wiring

1. Lighting - 3/20 copper wire

2. Heating - 7/20 copper wire

The enamel coating (on the individual

strands) mutually insulates the strands and the overall wire is provided

with PVC insulation. The current carrying capacity depends on the total

area of the wire. If cost is the criteria then aluminium conductors are

preferred. In that case, for the same current rating much larger diameter

of wire is used.

67

References

69

Visiting Shops

71

1. http://www.fineswitches.com

2. http://www.fineproducts.com

3. http://www.havells.com

4. http://www.anchor-world.com

5. http://www.girishproducts.com

6. http://www.philips.com

7. http://www.ssk.com

8. http://www.ppiindia.net

Websites

http://www.fineswitches.com/

http://www.fineproducts.com/

http://www.havells.com/

http://www.anchor-world.com/

http://www.girishproducts.com/

http://www.philips.com/

http://www.ssk.com/

http://www.ppiindia.net/

survey report on house wiring

Education

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