Electrical wiring devices such as switches, sockets, distribution boards, and protective devices like fuses, MCBs, and MCCBs are introduced. Key devices discussed include single pole switches, two way switches, distribution boards, power sockets, ceiling roses, PVC casing, plugs, MCBs, MCCBs, earth leakage circuit breakers, cables, energy meters, gang boxes, cable connectors, fuses, and electrical conduit. The purpose of electrical wiring is to distribute electrical power safely and efficiently within a building for control of loads. Understanding wiring devices is important for proper electrical wiring installation.

1. OBJECT​:- ​INTRODUCTION TO THE WIRING DEVICES SUCH AS1
SWITCHES,SOCKETS,DISTRIBUTION BOARD ,PROTECTIVE DEVICES SUCH AS
FUSE,MCB,MCCB WITH THEIR FUNCTIONS​.
APPARATUS USED:
1. Single Pole Switch 2.Two Way Switch 3.Distribution Board 4.Power Socket
5. Ceiling Fuse 6.PCV ceiling 7.Plugs 8.MCB
9.MCCB 10.Cable 11.Energy Meter 12.Gang bar
13. Cable connectors 14.Changeover Switch
THEORY:-
Electrical wiring is the electrical power distribution through the wires in a perfect manner for
economic use of wiring conductors inside a room or building with better load control.
Knowing the knowledge about the wiring devices much needed so that we can perform
electric wiring in an efficient way.
1.SINGLE POLE SWITCH
The single-pole switch is the general-purpose workhorse
of switches. It is used to control a light, receptacle, or
another device from a single location. A characteristic
feature of a single-pole toggle switch is that it has ON
and OFF markings on the toggle. This is something you
will not find on three-way or four-way switches.
A single-pole switch has two brass-colored screw
terminals and is wired to the "hot" (current-carrying) wire,
which is usually black. One brass terminal is for the
incoming hot wire, and the other is for the outgoing hot
wire to the device. Most single-pole switches also
include a ground terminal for connecting the circuit's ground wire.
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2. 2.TWO WAY SWITCH(DOUBLE-POLE SWITCH)
The double-pole switch is commonly used in industrial applications but can be found in some
home wiring systems. Like the single-pole switch, a double-pole has ON and OFF markings and
controls a device or equipment from one location. The main
difference is that a double-pole switch has four hot brass terminals
(instead of two), plus a ground, allowing you to connect it to two
pairs of hot wires from a 240-volt circuit.
Double-pole switches are commonly rated for 30 amps (compared
to 15 or 20 amps with standard switches), so they can control
higher-demand appliances, motors, and machinery.
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3. Distribution Board
A distribution board (also known as panelboard, breaker panel, or electric
panel) is a component of an electricity supply system that divides an
electrical power feed into subsidiary circuits, while providing a protective
fuse or circuit breaker for each circuit in a common enclosure.
Fig:Symbol of Distribution Board
4.POWER SOCKET
​Power sockets are electric equipment to be connected
to the primary alternating current (AC) power supply in
buildings and at other sites. It differs from one another in
voltage and current rating, shape, size, and connector
type. Different systems of sockets have been
standardized, and different standards are used in
different parts of the world.
Figure:-Power socket.
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3. 5.LAMP HOLDER
Lampholders provide electrical connections to the lamps and support it in the lighting fixture. The
use of sockets allows lamps to be safely and conveniently replaced (re-lamping). There are many
different standards for these lampholders, created by ​de facto and by various standards bodies. A
general coding system is a letter or abbreviation followed by a number.​[1]
Some miniature lamps
have wire leads suitable for direct connection to wires; some reflector lamps have screw terminals
for wire connections.
Fig: Symbol of lamp holder.
6.CEILING ROSE
a ​ceiling rose is a decorative element affixed to the ceiling from which a chandelier or light fitting is
often suspended. They are typically round in shape and display a variety of ornamental designs.
Fig: Ceiling Rose
7.PVC CASING
PVC insulated wires are placed in plastic cashing and covered with cap. The cashing is of
rectangular cross section which function is to protect the wires
8.PLUG
a device for making an electrical connection between an appliance and
the mains, consisting of an insulated casing with metal pins that fit into
holes in a socket.

4. 9.MCB
An MCB or miniature circuit breaker is an electromagnetic device that embodies complete
enclosure in a molded insulating material. The main function of an MCB is to switch the circuit,
i.e., to open the circuit (which has been connected to it)
automatically when the current passing through it (MCB) exceeds
the value for which it is set. It can be manually switched ON and
OFF as similar to normal switch if necessary.
Fig:-MCB
10.MCCB
​Molded case circuit breaker, abbreviated MCCB, is a type of
electrical protection device that can be used for a wide range of voltages, and frequencies of
both 50 Hz and 60 Hz. The main distinctions between molded-case and miniature circuit
breaker are that the MCCB can have current ratings of up to 2,500 amperes, and its trip settings
are normally adjustable. An additional difference is that MCCBs tend to be much larger than
MCBs
11.EARTH LEAKAGE CIRCUIT BREAKER
An Earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations with
high Earth impedance to prevent shock. It detects small stray voltages on the metal enclosures
of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. Once widely
used, more recent installations instead use residual current circuit breakers which instead detect
leakage current directly.
12.CABLE
An electrical cable is of two or more wires, or
conductors, that form a single cable assembly
from the wires being twisted, bonded or
braided together. You'll find cables used most
in the home and for power and signal circuits
in electronic devices.
13.ENERGY CABLE

5. An electricity meter, electric meter, electrical meter, or energy meter is a device that measures
the amount of electric energy consumed by a residence, a business, or an electrically powered
device.
Electric utilities use electric meters installed at customers' premises for billing purposes. They
are typically calibrated in billing units, the most common one being the kilowatt hour (​kWh​).
They are usually read once each billing period.
When energy savings during certain periods are desired, some meters may measure demand,
the maximum use of power in some interval. "Time of day" metering allows electric rates to be
changed during a day, to record usage during peak high-cost periods and off-peak, lower-cost,
periods. Also, in some areas meters have relays for demand response load shedding during
peak load periods
Fig:-Energy meter
14.GANG BOX
Gang box is also a term in the electrical industry used to indicate a box, usually metal, which
houses installed electrical componentry. A 1-gang box hosts a single component such as a
switch or receptacle, a 2-gang box hosts two components side-by-side, and so on.
15.CABLE CONNECTORS
A small structure which is use to join the two connectors
16.FUSE

6. A fuse is an electrical safety device that operates to provide overcurrent protection of an
electrical circuit. Its essential component is a metal wire or strip that melts when too much
current flows through it, thereby interrupting the current. It is a sacrificial device; once a fuse has
operated it is an open circuit, and it must be replaced or rewired, depending on type.
Fuses have been used as essential safety devices from the early days of electrical engineering.
Today there are thousands of different fuse designs which have specific current and voltage
ratings, breaking capacity and response times, depending on the application. The time and
current operating characteristics of fuses are chosen to provide adequate protection without
needless interruption. Wiring regulations usually define a maximum fuse current rating for
particular circuits. Short circuits, overloading, mismatched loads, or device failure are the prime
reasons for fuse operation​.
17.CONDUIT
An electrical conduit is a tube used to protect and route electrical wiring in a building or
structure. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Most conduit is
rigid, but flexible conduit is used for some purposes.
Conduit is generally installed by electricians at the site of installation of electrical equipment. Its
use, form, and installation details are often specified by wiring regulations, such as the US
National Electrical Code (NEC) and other building codes.