Electrical safety & its needs

2014-15
Seminar On
SUBMITTED BY CLASS TEACHER
NAVEED KHAN PROF. IMRAN
ROLL No:-34021
T.E ELECTRICAL

Outline
 Introduction
 Safety Terminology
 Electrical Terminology
 Hazards of Electricity
 Causes of Electrical Accidents
 Effect of Electricity on the Human Body
 Procedures for rescuing the person who have
receive an electric Shock
 Causes of fire due to Electrical Reasons
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Introduction
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Safety education must be
an integral part of technology
instruction. In order to prevent
injury to students and teachers,
good safety habits, practices and
attitudes can best be acquired
through a carefully planned and
implemented safety education
program.

Safety Terminology
 Safety: The meaning of the term safety is being safe, not
being dangerous or in danger.
 Accident: The event that happens unexpectedly and causes
damage or injury.
 Responsibility: The meaning of responsibility is being
responsible or accountable.
 Authority: The person who has power to give orders and
make others to obey the same.
 Accountability: It is expected from the person incharge of
certain work to give an explanation of something goes
wrong.
 Monitoring: The continuous observations of record or test
of operation of a machine/equipments are carried out.
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Electrical Terminology
 VOLTAGE – Unit of measurement of electromotive force
(EMF) in Volt.
 CURRENT – Continuous movement of electrons in
Ampere.
 RESISTANCE – Opposition to movement of electrons in .
 CONDUCTORS – Substances, such as metals, that have
little resistance to electricity.
 INSULATORS – Substances, such as dry Wood, Rubber,
Glass and Bakelite, that have high resistance to electricity.
 GROUNDING – A conductive connection to the earth
which acts as a protective measure.
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Hazards of Electricity
The things that arise without planning
or Random
 Inadequate wiring
 Exposed electrical parts
 Wires with bad insulation
 Ungrounded electrical tools /systems
 Overloaded circuits
 Damaged power tools / equipment
 Overhead power lines
All hazards are made worse in wet
conditions.
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 In electrical systems, it is
quite possible that faults
may develop haphazardly
causing the disturbance in
the system.
 Whenever there is a
breakdown of insulation
over the wires, it is always
accompanied by generation
of heat and increase of
temperature near about the
fault, resulting fire hazard.
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Causes of Electrical Accidents
 A person touches a live wire.
 If the metal frame (body) is
touched.
 Faulty machine touch by a
person.
 Fault puncturing Transformer
insulation making core live,
touched by a person.
 Loose live jumper touching
pole or stay.
 Damage of insulation of cables
used for connecting the
machines.
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 Wet walls resulting into
leakage of electric
current.
 Operation of switches
with wet hands.
 If water is used for
quenching fire.
 Line fed from both sides,
if not known to persons
working.
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Effect of Electricity on the Human
Body
Depends on:
 Voltage of the System
 Current passing through the Body
 Part of the Body involved
 Period for which organ remains in contact
with live part
 Resistance of the Body
 Supply System
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Effects of Current on Human System
 1mA to 8mA: Perceptible, does not cause any pains.
 8mA to 15mA: Painful shock without loss of Muscular
control.
 15mA to 20mA: Painful shock, muscular control of
adjacent muscles lost.
 20mA to 50mA: Severe muscular contraction, breathing
becomes difficult.
 50mA to 100mA: It may result in ventricular fibrillation,
may result in instant death.
 200mA & Above: Severe burns, muscular contraction so
severe that chest muscles clamp down the heart & stop
it. This prevents ventricular fibrillation.
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Procedures for Rescuing the person who
have receive an Electric Shock
 Switch off electric circuit and remove the body
from contact.
 If cutting of supply is not immediately possible,
remove the body from live conductor by wooden
rod, bundle of paper etc. without touching him.
 Call the doctor.
 Artificial respiration should be started immediately.
 Artificial breathing should be continued till he
breath normally or until the doctor will come.
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Causes of fire due to Electrical
Reasons
 If poor quality of
material is used
 Setting of Relay may
be incorrect or fails to
operate
 Short circuit
(Symmetrical &
Unsymmetrical fault)
 Overheating damaging
insulation
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Precaution to avoid fire due to
Electrical Reason
 Use proper rating of fuse & Relays.
 Indian Electricity rules should be followed.
 A very good earthing should be provided to every
equipments & machine.
 Insulation of connecting wires should be of very
good quality.
 Other material use for providing connection should
also be of good quality.
 Fire fighting equipments be kept ready at all times.
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Operation of Fire Extinguishers
 Effected part shall immediately
be completely isolated form its
source of supply.
 Fire extinguishers, which are not
insulated, should never be used
in fighting fires near exposed
live conductors.
 Jet of water does not come into
contact with live conductors.
 For electrical fire the CO2
extinguisher are the best.
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