Electrical Safety
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Agenda
1
Introduction
2
Hazards
3
Control Measures
4
Legal Requirements
5
Site Practices
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An Important Quote…
Concern for Man Himself and
for His Safety must always from
the chief interest of all technical
endeavor.
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Introduction
Electricity is the set of physical
phenomena associated with the
presence and motion of matter
that has a property of electric
charge.
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Basic Principles
Electric current always flows throug
a conductor.
Always passes through a
conductor.
Ultimately reaches into the earth
surface.
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Definitions
Current
Charge flowing through a conductor
in unit time. Unit of measurement is
Amp.
Voltage
It is a pressure from which the charge
flowing through a conductor in unit
time. Unit of measurement is Volt
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Resistance
Resistance is any condition which
retards current flow. Unit is Ohms.
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Hazards of Electricity
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•
•
•
•
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Electrical shock
Electrical fire
Flash over
Radiation
Explosion
Indirect effects
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Hazards of Electricity
• Electrical Shock
Shock occurs when the body becomes part of the electric
circuit.
- Contact with Both Wired of the Electric Circuit
- With one wire of an energized circuit and the ground
- Touching Energized Metallic Part and standing on
Ground
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Hazards of Electricity
• Electrical Fire
Fire in an Electric Circuit happens because of the
following reasons.
- Over Loading.
- Incorrect Fuses/Protective Devices.
- Poor Maintenance
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Hazards of Electricity
• Explosion
Electricity does not explode in itself but aids in causing
explosion if;
- Presence of explosive fumes/vapours.
- Presence of flammable gas cylinders in the vicinity of
the flames/arcs
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Hazards of Electricity
• Flash over
An electric arc (sometimes referred to as “electrical
flashover”) is a continuous electric discharge of high
current which flows through an air gap between
conductors.
This generates
- a very bright ultra-violet light
- intensive heat.
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Hazards of Electricity
• Indirect effects
Some of the indirect effect of electricity, when a person
received electrical shock is;
- Fall
- Drowning
- Cut & Abrasion
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Ohm’s Law
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Effects of Current
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Electrical Shock
We Receive electrical shock,
when our body becomes part
of the electrical circuit.
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Severity of Electrical Shock
The severity of electrical shock depends on :
1. the path the current travels
2. the amount of voltage, and
3. the type of current (AC or DC)..
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Alternate Current (AC) vs Direct Current (DC)
AC
(1)
(2)
(3)
DC
Current of 60 mA of AC can
cause fibrillation
AC is more dangerous to our
Heart
Four times severe than AC
current
(1)
(2)
(3)
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Current of 300–500 mA
of DC can cause fibrillation
DC is more dangerous to our
body. More likely to freeze the
victim
Relatively Safer than AC current
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Human Resistance to Electrical Current
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Shock Protection Devices
Fuse Unit
Miniature
Circuit Breaker
Insulator
Guarding
Earth Leakage
Circuit Breaker
Earthing
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Residual Current
Circuit Breaker
PPEs
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Legal and Other Requirements
Indian Electricity Act, 2003
Indian Electricity Rules, 2005
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National Electricity Code
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Legal and Other Requirements, IE Rules, 2005
Rule-3: Authorisation
Provides provision for authorization by a supplier or a consumer
Rule 29: Construction, Installation, Protection……
Ensure safety of human beings, animals and property”
Rule 30: Service Lines and Apparatus on Consumer Premises……
The consumer shall also ensure that the installation under his control is maintained in a safe condition.
Rule 31: Cut out at Consumer Premises ……
Provide a suitable cut-out in each conductor of every service-line other than an earthed...
Rule 35: Danger Notice……
Affix permanently in a prominent position a danger notice in Hindi English or local language...
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Legal and Other Requirements, IE Rules, 2005
Rule-36: Handling of Electrical Supply Lines
Stipulates to ensure adequate safety precautions before handling of electric supply lines and apparatus
Rule 41: Distinction of Different Circuits……
Means of indication of permanent nature.
Rule 44: Instruction on Restoration of Persons receiving electrical shocks……
Requirement of affixing instructions for restoration of persons suffering from electric shock
Rule 44A: Notification of Accidents
Information shall send to the Inspector a telegraphic report within 24 hours
Rule 45: Precautions to be adopted by Consumer
Measures to be adopted by consumers, Owners, occupiers, electrical contractors, electrical workmen and suppliers…
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Clearances to be maintained…..
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Site Practices
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Site Practices
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Site Practices
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Site Practices
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Site Practices
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Site Practices
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And Finally…
Make it a good Servant
Not a Bad Master
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