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 inAmpere.

RESISTANCE – Opposition to movement of electrons in .

CONDUCTORS – Substances, such as metals, that havelittle 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 earthwhich 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 isquite possible that faultsmay develop haphazardlycausing the disturbance inthe system.

Whenever there is abreakdown of insulationover the wires, it is alwaysaccompanied by generationof heat and increase oftemperature near about thefault, 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 Muscularcontrol.

15mA to 20mA: Painful shock, muscular control ofadjacent muscles lost.

20mA to 50mA: Severe muscular contraction, breathingbecomes difficult.

50mA to 100mA: It may result in ventricular fibrillation,may result in instant death.

200mA & Above: Severe burns, muscular contraction sosevere that chest muscles clamp down the heart & stopit. 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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