Electrical safety is important to prevent accidents and protect lives. The document discusses several key points: 1. Electrical accidents are common in India, causing 15-16 deaths per day from electrocution. Improper electrical safety also causes fires and loss of production. 2. Federal OSHA regulations in the US (1910.301-399) address electrical safety topics like live parts, grounding, electrical box covers, and flexible cord protection which have resulted in hundreds of citations each year. 3. Proper electrical safety involves protecting operating personnel, equipment, electrical components, and property from emergencies through compliance with regulations and safety practices.

1. ELECTRICAL SAFETY
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2. ELECTRICAL SAFETY
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3. Statistics of Electrical accident in India
And effects
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• 15 -16 deaths / day due to electrocution
• 30 - 35 % of fires are of electrical origin
• 8% of fatal accidents in factories are due to electrocution
• Un-estimated loss of production
• Business interruption
• Loss of management time
• Legal costs
• Negative impact on company/ Organization's image.

4. 4
Subpart S - Electrical
(1910.301 - 399)
515
457
396
347
290
303(g)(2)(i)
305(b)(1)
304(f)(4)
305(b)(2)
305(g)(1)(iii)
Live parts
Grounding path
Electrical box covers
Conductors entering cabinets/boxes/fittings protected from abrasion
Standard:
1910.
Use of flexible cords and cables
*
*
*
*
*
*Average number of Federal OSHA citations issued
between 2000 and 2003

5. ELECTRICAL SAFETY
• Safety of operating person and neighbourhood
• Safety of major equipments / Protection
• Safety of electrical equipments, gadgets, lines,
cables, etc,.
• Safety of properties
• Protection against emergencies and Unexpected
happenings
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6. DEFINITION
A physical agency caused by the motion
of electrons, protons, and other
charged particles, manifesting itself as
an attraction, repulsion, magnetic,
luminous, and heating effects, etc.

7. ELEMENTS & ATOMS
Every known substance – solid, liquid or
gas is composed of elements
An atom is the smallest particle of an
element that retains all the properties
of that element
Each element has it’s own kind of atom

8. ATOMS
Inner part composed of protons & neutrons
Outer part composed of electrons
Protons = positive charge
Neutrons = no charge
Electrons = negative charge

9. ATOMS
Each element has a definite number of
electrons ----and the same number of
protons
They are oppositely charged and
therefore attract each other. This tends
to hold the electrons in orbit around the
atom.

10. ELECTRICALLY BALANCED
ATOM

11. FREE ELECTRONS
Some atoms are easily moved out of orbit
The ability to move or flow is the basis of
current electricity
If channeled in a given direction, a flow of
electrons occurs --- when flowed through a
conductor it is dynamic electricity

12. ELECTICAL MATERIALS
CONDUCTOR – contains many free
electrons --- gold, copper, silver,
aluminum
INSULATOR – contains few free
electrons-Usually non-metallic such as
wood, rubber, glass, etc

13. GENERATING ELECTRICITY
Friction, pressure, heat, light, chemical
reaction, and magnetism
Magnetism is most practical & inexpensive
method
Electricity is produced when a magnet is
moved past a piece of wire, or wire is
moved through a magnetic field

14. VOLTAGE, CURRENT, &
RESISTANCE
VOLTAGE – unit of measurement of electromotive
force (EMF)
CURRENT - Continuous movement of electrons past a
given point. (measured in amperes)
RESISTANCE – Opposition to movement of electrons.
Makes it possible to generate heat, control current
flow, & supply correct voltage to devices

15. OHM’S LAW
George Simon Ohm
 Formulated a mathematical relationship between:
 Current
 Voltage
 Resistance
 Resistance = Impedance
 Resistance = DC
 Impedance = AC
 Interchangeable – Most Branch circuits

16. DIRECT CURRENT
Always flows in one direction
Used to charge batteries, run some
motors, operate magnetic lifting devices
and welding equipment.

17. ALTERNATING CURRRENT
More common in electrical work
Changes rapidly in both direction and
value
Power companies produce power
cheaper with alternating current

18. MAJOR CAUSES OF ELECTRICAL ACCIDENTS
4
 Carelessness
 Misuse
 Getting in a hurry
 Lack of interest
 Insufficient training
 Ignorance
 Fear
 Over confidence
 Sadness
 Anger
 Laziness
 Negligence
 Distractions
 Mischievous behaviorTANGEDCO

19. MAJOR CAUSES OF ELECTRICAL ACCIDENTS
4

20. EARTHING

21. EARTH RESISTANCE

22. WHAT CAUSES SHOCK?
Passage of Electric Current through the Body – 50 mA is
enough to cause ventricular fibrillation
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2

23. VOLTAGE CLASSIFICATION

24. SECTION CLEARANCE

25. GROUND CLEARNCE

26. EQUIPMENT CLEARANCES

27. LOWEST CONDUCTOR ON STREET CLEARNCES

28. CLEANCES FROM BUILDING

30. EARTHING

31. ACCIDENTS REPORTING TIME

34. CLEARANCE FROM BUILDING

35. PHASE TO EARTH CLEANCES

36. KV Min ROW
66 KV 18 Meter
132 KV 27 Meter
220 KV 35 Meter
400KV 52 Meter (Single Circuit)
400 KV 48 Meter (Double Circuit)
Code: Indian Electricity Rules / Central Electricity Authority
Right of Way Clearance

37. Voltage 66 KV 132 KV 220 KV 400 KV
66 KV 2.4 Meter 3 Meter 4.5 Meter 5.4 Meter
132 KV 3 Meter 3 Meter 4.5 Meter 5.4 Meter
220 KV 4.5 Meter 4.5 Meter 4.5 Meter 5.4 Meter
400 KV 4.5 Meter 5.4 Meter 5.4 Meter 5.4 Meter
Minimum clearances between Electrical Lines crossing each other

38. 3D VIEW LAYOUT

39. 3D VIEW LAYOUT

40. STEP AND TOUCH POTENTIAL
1. During Short circuit current Step and Touch potential
increases.
Step potential : It is the potential developed between
the two feet on the ground of a man or animal when
short circuit occurs. This results in flow of current in the
body leads to electrical shock.
Touch potential: It is the potential that is developed
between the ground and the body of the equipment
when a person touches the body during fault condition.
When operating personnel touch an electrical
equipment during short circuit condition, fault current
flows through the human body. This is defined as touch
potential.

41. TOUCH POTENTIAL

42. STEP POTENTIAL

43. GRAVEL -WHY
Gravel/Stones in the substation is provided to reduce
the step potential and touch potential when operators
work on switch yard.
2. Power Transformers installed in the substations will
have oil as cooling and insulating medium. Oil leakage
takes place during operation or when changing the oil
in the transformer. This oil spillage which can catch fire
is dangerous to the switchyard operation. So
Stones/Gravel is provided to protect from fire when oil
spillage takes place.
3. Stones eliminate the growth of small weeds and
plants inside the switch yard
4. Improves yard working condition
5. Provides protection from wild life and snakes.

44. HUMAN BODY’s RESISTANCE TO ELECTRICITY
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4
Sl.
No.
Path for flow of electricity Voltage (Volts)
127 V 220 V > 220 V
Resistance value (In dry condition)
1 From Inner Palm of the
hand to Shoulder
2.5 K Ω 0.85 K Ω 0.65 K Ω
2 From Palm of the hand to
Leg Foot or From shoulder
to Leg Foot
2.8 K Ω 1.2 K Ω 0.8 K Ω
3 From Inner Palm of the
hand to other
3.4 K Ω 1.6 K Ω 1.2 K Ω
• Effect of 120 V DC is same as 42 V AC
• When the body is wet or humid, the above conditions will differ

45. DANGERS CAUSED BY FLOW OF ELECTRIC
CURRENT THROUGH HUMAN BODY
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5
Sl. No. Value of
current in mA
Effects
1 1 to 8 Not painful but perceptible
2 8 to 15 Pain full shock, Muscular control not lost, Individual can
let go the conductor
3 15 to 20 Pain full shock, Muscular control not lost, Individual
cannot let go the conductor
4 20 to 50 Severe muscular contraction, Breathing difficulty
5 50 to 100 Ventricular fibrillation, May result in electrocution and
death
6 > 100 mA Severe burns, immediate cardiac arrest and ceasing of
heart and immediate death
• Time of contact , I = 0.165 / t ,
• t = 0.03 to 3 sec for I = 40 to 50 mA will cause death

46. Fibrialliation
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6
• Fibrillation is usually lethal because all of the
heart muscle fibres move independently
instead of in the coordinated pulses needed to
pump blood and maintain circulation
• A domestic power supply voltage (110 or 230
V), 50 or 60 Hz alternating current (AC) – 50
mA
• With direct current (DC), 300 to 500 mA is
required.

47. Arc flash hazards
• The arc flash in an electrical fault produces the
same type of light radiation from which
electric welders
• The heat produced may cause
severe burns, especially on
unprotected flesh.
• The arc blast produced by vaporizing metallic
components can break bones and damage
internal organs.
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48. Copyright © 2016 Your Company All Rights Reserved. 48
WHY SHOULD WE WEAR ARC SUIT

49. Reasons for accidents
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•Unsafe acts
•Unsafe conditions
•Natural calamities
•Unexpected happenings

50. Effects of accidents
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1. To individuals
• Electrocution / Death
• Permanent Physical disability
2. To Management
• Loss of working days
• Delay in completion
• Compensation
• Job to legal heirs on compassionate grounds
• Legal disputes

51. Remedies
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1. Safety classes
2. Display of Safety slogans
3. Proper supervision
4. Execution of work as per instructions
5. Proper communication
6. Adopting Safety rules and regulations

52. Regulations on Safety
•CEA Safety Regulations, 2010
•Electricity Act, 2003
Setting up State Electricity Regulatory Commission (SERC)
has been made mandatory.
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53. Other safety aspects
• Use only electrical gadgets with ISI mark and carry out all electrical works by
certified electricians
•Inspect electrical wiring regularly and renew deteriorated wiring
•Do not go near or touch the electric poles, stay wires, fencing etc., during rainy
seasons
•Do not use electric poles as support to pandals or displaying advertisement Board
•Do not construct buildings near electric lines, consult the Electricity Board officials
before planning for the same
•Do not go near the fencing of electrical transformers/ substations for nature’s call
•Do not park lorries near transformer structure or electric line and carry out loading
and unloading of materials.
•Do not drive vehicles, carry ladders etc, which are of greater height beneath the
electric lines.
•While digging the ground for other works, care should be taken while working near
underground electric cables. TANGEDCO 21

54. Safety in Circuits
•ELCBs
• Rated for 30, 50, 100, 200, 300 mA
• Must for all circuits
• Should be connected to earth
• Another Energy Conservation technique
by restricting the leakage current in
circuit
• Separate lighting and power circuits
• Protection aspects
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55. ELECTRICAL SHORT CIRCUIT AT AGENCY CONSTRUCTION OFFICE

56. CABLE DAMAGE AT GATE COMPLEX

57. AHP AREA FLASH- HEALTHY TB

58. AHP AREA FLASH

59. CT TB IMPROVEMENT

60. RING TYPE SHORTING LINK

61. Touching snapped wire causing fatal
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62. TANGEDCO 62

63. Fencing protects against danger
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64. Crossing power line holding metal stick
vertically causing accident
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65. Operating the vehicle under power line
causing accident

66. Working under power line causing accident

67. Operating Earth Mover under power line
causing accident

68. Operating crane under power line
causing accident

69. Desilting tank and packing huge earth
under power line causing accident

70. Relaxing on lamp post or touching exposed
wire in lamp post causing accident

71. Handling iron / Aluminium rods on terrace
nearer to power line causing accident

72. Getting down from car is a chance of
electrocution if snapped wire is live
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73. Popular error: The rubber tires on a car protect
you from Lightning.
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74. Lightning makes work Hazardous
74

75. “It's not voltage that kills, its current!"
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76. Stop working in thunder storm
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77. OVER VOLTAGE
Voltage spike
When the voltage in a circuit or part of it is raised
above its upper design limit, this is known
as overvoltage. The conditions may be hazardous.
Depending on its duration, the overvoltage event can
be transient, a voltage spike or permanent, leading to
a power surge.

78. Lightning
• The over voltages come either from the
electricity network or from the earth.
• FACTS ABOUT LIGHTNING
– A strike can average 100 million volts of electricity
– Current of up to 100,000 amperes
– Can generate 54,000 OF
– Lightning strikes somewhere on the Earth every
second
– Kills hundreds of people every year

79. Lightning phenomenon
• Developmental stages of a lightning flash and
corresponding current surge

80. Effects of lightning
• Lightning strokes represent true danger to life,
structures, power systems, and communication
networks.
• Lightning is always a major source of damage to
power systems where equipment insulation may
break down, under the resulting overvoltage and
the subsequent high-energy discharge
• The main effect of lightning is electrical overvoltage
which exposes the electrical installations to a
serious risk of:
● malfunction,
● destruction of equipment,
● unavailability of machineries and equipments

81. Lightning protection of Houses

82. CONNECT ONLY ONE APPLIANCE
TO ONE SOCKET
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83. Do not use 2 pin socket & plug
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84. NEVER KEEP WIRES UNDER CARPETS, MATS OR DOOR
WAYS WHERE THEY CAN GET CRUSHED & LOSE THEIR
INSULATION
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85. USE THE CORRECT SIZE AND QUALITY OF FUSE. A FUSE OF
HIGHER RATING WILL NOT BE SAFE AS IT ALLOWS
EXCESSIVE FLOW OF CURRENT WHICH WILL RESULT IN FIRE
OR SHOCK. BEFORE REPLACING A FUSE THE DEFECT IN THE
CIRCUIT OR EQUIPMENT MUST BE RECTIFIED
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86. KEEP WATER AWAY FROM ELECTRICAL FIXTURES. THE COMBINATION
OF WATER & ELECTRICITY IS A POTENTIAL SHOCK HAZARD
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87. Water leakage sometimes proves fatal
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THE HINDU
SATURDAY,
DECEMBER 3, 2005
Kalaiyarasan (18) a
resident of Rajiv
Gandhi Nagar,
Maduravoil was
Electrocuted when
switching on light
in his house
Please note that Dec 2nd
is a heavy rainy day

88. SEE THAT APPLIANCE CORDS ARE IN GOOD CONDITION.
USING BLACK ADHESIVE TAPE FOR JOINT IS NOT SAFE.
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89. NEVER PLACE BARE WIRE ENDS IN A SOCKET.
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90. Don’t use match stick in lieu of plug
Don’t let earth wire unconnected
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91. Burn injury due to tapping power supply for lighting from 3 phase
power switch
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92. Do not mount switches & provide plug points
at accessible position to children
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93. Broken switch cover kills guest
Ahhh! Shockk!
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94. USE GOOD QUALITY MATERIALS. BUY FROM REPUTED
SHOPS. DONOT BUY SECOND HAND GOODS
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95. TANGEDCO 95

96. PPT 10-hr. General Industry – Electrical v.03.01.17
96
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