How Earthing works. What is earthing all in one for students and others? Types of Earthing. description that is needed. You can get to know how important Earthing is.

1. EARTHINGEARTHING
ByBy
Aditya JeeAditya Jee
Class -Class -IX BIX B
Roll NoRoll No..-- 0202

2. ContentContent
 IntroductionIntroduction
 ImportanceImportance
 UsesUses
 Types of EarthingTypes of Earthing
 PhotosPhotos

3. IntroductionIntroduction
In electricity supply systems, an earthing (grounding)In electricity supply systems, an earthing (grounding)
system defines the electrical potential of thesystem defines the electrical potential of the
conductors relative to that of the Earth's conductiveconductors relative to that of the Earth's conductive
surface. The choice of earthing system hassurface. The choice of earthing system has
implications for the safety and electromagneticimplications for the safety and electromagnetic
compatibility of the power supply. A functional earthcompatibility of the power supply. A functional earth
connection serves a purpose other than providingconnection serves a purpose other than providing
protection against electrical shock. In contrast to aprotection against electrical shock. In contrast to a
protective earth connection, a functional earthprotective earth connection, a functional earth
connection may carry a current during the normalconnection may carry a current during the normal
operation of a device. Functional earth connectionsoperation of a device. Functional earth connections
may be required by devices such as surgemay be required by devices such as surge
suppression and electromagnetic-compatibility filters,suppression and electromagnetic-compatibility filters,
some types of antennas and various measurementsome types of antennas and various measurement
instruments. Generally the protective earth is alsoinstruments. Generally the protective earth is also
used as a functional earth, though this requires care inused as a functional earth, though this requires care in
some situations.some situations.

4. ImportanceImportance
Earthing is as important as the fuses in the wiringEarthing is as important as the fuses in the wiring
circuits i.e. in the case of short circuits or overcircuits i.e. in the case of short circuits or over
loads, the heavy current flows through the wiresloads, the heavy current flows through the wires
and fitting etc. which melts the fuse wire and stopsand fitting etc. which melts the fuse wire and stops
the flow of current in the circuits, thus save thethe flow of current in the circuits, thus save the
whole circuit from being damaged.whole circuit from being damaged.
Similarly, when any live or phase wire touches theSimilarly, when any live or phase wire touches the
metal part of the fitting, appliance, machine ormetal part of the fitting, appliance, machine or
equipment, the current passes through the earthequipment, the current passes through the earth
wire, if the appliance, equipment or machine etc.wire, if the appliance, equipment or machine etc.
are connected with proper earth connection, blowsare connected with proper earth connection, blows
the fuse at once and saves the operator fromthe fuse at once and saves the operator from
getting shock. Thus to avoid these dangers, allgetting shock. Thus to avoid these dangers, all
metal parts of the fitting, appliances, equipment,metal parts of the fitting, appliances, equipment,
machines etc are earthed.machines etc are earthed.

5. UsesUses
In mains-In mains- powered equipment, exposed metalpowered equipment, exposed metal
parts are connected to ground to prevent userparts are connected to ground to prevent user
contact with dangerous voltage if electricalcontact with dangerous voltage if electrical
insulation fails. Connections to ground limit theinsulation fails. Connections to ground limit the
build-up of static electricity when handlingbuild-up of static electricity when handling
flammable products or electrostatic-sensitiveflammable products or electrostatic-sensitive
devices. In some telegraph and powerdevices. In some telegraph and power
transmission circuits, the earth itself can betransmission circuits, the earth itself can be
used as one conductor of the circuit, savingused as one conductor of the circuit, saving
the cost of installing a separate returnthe cost of installing a separate return
conductor.conductor.

6. For measurement purposes-For measurement purposes- the Earth serves as athe Earth serves as a
(reasonably) constant potential reference(reasonably) constant potential reference
against which other potentials can beagainst which other potentials can be measured.measured.
An electrical ground system shouldAn electrical ground system should have anhave an
appropriate current-carryingappropriate current-carrying capability to serve ascapability to serve as
an adequate zero-an adequate zero- voltage reference level.voltage reference level.
In electronic circuitIn electronic circuit theory, a "ground" is usuallytheory, a "ground" is usually
idealized as anidealized as an Infinite source or sinks for charge,Infinite source or sinks for charge,
which canwhich can absorb an unlimited amount of currentabsorb an unlimited amount of current
withoutwithout changing its potential. Where a realchanging its potential. Where a real
groundground connection has a significant resistance,connection has a significant resistance,
thethe approximation of zero potential is no longerapproximation of zero potential is no longer
valid. Stray voltages or earth potentialvalid. Stray voltages or earth potential rise effectsrise effects
willwill occur, which may createoccur, which may create noise in signals ornoise in signals or
if largeif large enough willenough will produce an electricproduce an electric
shock hazard.shock hazard.

7. Electrical power distribution-Electrical power distribution-
These systems are often connected to ground toThese systems are often connected to ground to
limit the voltage that can appear on distributionlimit the voltage that can appear on distribution
circuits. A distribution system insulated fromcircuits. A distribution system insulated from
ground may attain a high potential due toground may attain a high potential due to
transient voltages caused by arcing, statictransient voltages caused by arcing, static
electricity, or accidental contact with higherelectricity, or accidental contact with higher
potential circuits. A ground connection of thepotential circuits. A ground connection of the
system dissipates such potentials and limits thesystem dissipates such potentials and limits the
rise in voltage of the grounded system.rise in voltage of the grounded system.
Types of EarthingTypes of Earthing

8. Equipment earthing conductors-Equipment earthing conductors-
It provide an electrical connection between nonIt provide an electrical connection between non
current-carrying metallic parts of equipmentcurrent-carrying metallic parts of equipment
and the earth. According to the U.S. Nationaland the earth. According to the U.S. National
Electrical Code (NEC), the reason for doing this isElectrical Code (NEC), the reason for doing this is
toto
limit the voltage imposed by lightning, line surges,limit the voltage imposed by lightning, line surges,
and contact with higher voltageand contact with higher voltage
lines. The equipment earthinglines. The equipment earthing
conductor is usually also usedconductor is usually also used
as the equipment bondingas the equipment bonding
conductor.conductor.

9. Equipment bonding conductors-Equipment bonding conductors- IItt provide a low impedanceprovide a low impedance
path between non-current-carrying metallic parts ofpath between non-current-carrying metallic parts of
equipment and one of the conductors of that electricalequipment and one of the conductors of that electrical
system's source, so that if a part becomes energized forsystem's source, so that if a part becomes energized for
any reason, such as a frayed or damaged conductor, aany reason, such as a frayed or damaged conductor, a
short circuit will occur and operate a circuit breaker or fuseshort circuit will occur and operate a circuit breaker or fuse
to disconnect the faulted circuit. Note that the earth itselfto disconnect the faulted circuit. Note that the earth itself
has no role in this fault-clearing process since current musthas no role in this fault-clearing process since current must
return to its source, not the earth as is sometimes believed.return to its source, not the earth as is sometimes believed.
By bonding all exposed non-current carrying metal objectsBy bonding all exposed non-current carrying metal objects
together, they should remain near the same potential thustogether, they should remain near the same potential thus
reducing the chance of a shock. This is especiallyreducing the chance of a shock. This is especially
important in bathrooms where one may be in contact withimportant in bathrooms where one may be in contact with
several different metallic systems such as supply and drainseveral different metallic systems such as supply and drain
pipes and appliance frames. The equipment bondingpipes and appliance frames. The equipment bonding
conductor is usually also used as the equipment earthingconductor is usually also used as the equipment earthing
conductor.conductor.

10. PhotosPhotos