Electrical Hazards in Construction

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1. Slide 1

   Electrical Hazards in Construction

   • A Language and Literacy Appropriate Safety
   • Training
   • This material was produced under a grant (SH-05044-SH8) from the Occupational Safety and Health Administration, U.S. Department of Labor. It does not necessarily reflect the views or policies of the U.S. Department of Labor, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.
2. Slide 2

   Disclaimer

   • No legal advice is offered or implied, and no attorney-client
   • relationship is intended or established. If legal advice or other expert assistance is required, the services of a competent professional should be sought.
   • It is the responsibility of the employer and its employees to comply with all pertinent OSHA rules and regulations in the jurisdiction in which they work.
3. Slide 3

   Objectives

   • Understand basic concepts of electricity
   • Recognize major types of electrical hazards in construction workplaces
   • Identify and prevent electrical accidents at construction sites
4. Slide 4

   Step-by-Step Training Agenda

   • Sign Up
   • Pre-Test
   • Basic Terms
   • Case Study
   • Training Modules
   • Electrical Hazards
   • Case Study
   • Electrical Incidents
   • Post-Test
   • Hazards Prevention
   • Feedback Survey
5. Slide 5

   Sign-In

   • It is time to fill out the sign-in sheet
6. Slide 6

   Pre-Test

   • Please Begin Pre-Test (15 Minutes)
7. Slide 7

   Pre-Test

   • Please Submit Pre-Test
8. Slide 8

   Training Modules Overview

   • Section I: Basic Terms and Case Study
   • Worker Rights under OSH Act
   • Electrical Hazards Statistics
   • Basic Terms of Electricity
   • A Case Study Discussion
   • Section II: Electrical Hazards (BESAFE)
   • Electrical Burn
   • Electrocution
   • Electrical Shock
   • Electrical Arc Flash
   • Electrical Fire
   • Electrical Explosion
9. Slide 9

   Training Modules Overview

   • Section III: Electrical Incidents in Construction
   • Contact with Power Lines
   • Lack of Ground-Fault Protection
   • Path to Ground Missing or Discontinuous
   • Equipment Not Used in Manner Prescribed
   • Improper Use of Extension or Flexible Cords
   • Contact with Energized Sources
10. Slide 10

    Training Modules Overview

    • Section IV: Electrical Hazards Prevention
    • Maintain Safe Distance from Overhead Power Lines
    • Use Ground-Fault Circuit Interrupters (GFCI)
    • Inspect Portable Tools and Extension Cords
    • Use Power Tools and Equipment as Designed
    • Follow Lockout/Tagout Procedures
    • Personal Protective Equipment
    • Isolate Electrical Parts
11. Slide 11

    Training Modules Overview

    • Section 1: Basic Terms and Case Study
    • Worker Rights under OSHA Act
    • Electrical Hazard Statistics
    • Basic Terms of Electricity
    • A Case Study Discussion
    • Section 2: Electrical Hazards (BESAFE)
    • Section 3: Electrical Incidents in Construction
    • Section 4: Electrical Hazards Prevention
12. Slide 12

    Worker Rights Under the OSH Act

    • Workers have rights to
    • Working condition without a risk of serious harm
    • Review employer’s records of work injuries and illnesses
    • Get a copy of their medical records
    • Receive information and training about hazards and prevention methods, and the OSHA standards
13. Slide 13

    Worker Rights Under the OSH Act

    • Workers have rights to
    • File a complaint asking OSHA to inspect workplace
    • OSHA will keep all identities confidential
    • Exercise rights under the law without retaliation
    • If a worker is retaliated against for using their rights, the worker must file a complaint with OSHA as soon as possible (no later than 30 days)
14. Slide 14

    Worker Rights Under the OSH Act

    • OSHA electrical safety standard for construction industry, in Title 29, Code of Federal Regulations (29 CFR 1926), mandates that “The employer shall instruct each employee in the recognition and avoidance of unsafe conditions and the regulations applicable to his work environment to control or eliminate any hazards or other exposure to illness or injury”.
15. Slide 15

    Electrical Hazard Statistics

    • According to U.S. Department of Labor, electrocution is top 3 causes of death in 2017
    • Falls – 381 deaths, Stuck by Object – 80 deaths
    • Electrocutions – 71 deaths (a death per 5 days)
    • Caught-in/between – 50 deaths
    • Workers are unaware of potential hazards
    • Safety training instruct workers safety knowledge
    • Safety knowledge reduces or eliminate risks of injury
    • Safety Knowledge is Life !
16. Slide 16

    Basic Terms

    • Electron: a particle with negative charge
    • Current: electrons movement
    • (1 ampere = 6×10 19 electrons moving per second)
    • No voltage across electrons
    • Electrons move randomly
    • No current flow
    • Current flow
    • Electron flow
17. Slide 17

    Basic Terms

    • Voltage: a force to push electron movement
    • Resistance: an obstacle to restrict electron movement
    • Voltage
    • Cable
    • (conductor)
    • Resistance
    • High voltage or low resistance make high current
18. Slide 18

    Basic Terms

    • Conductor: little resistance to electron movement
    • Insulator: high resistance to electron movement
    • Conductor
    • Little obstacle
    • All electrons pass through conductor
    • Insulator
    • Strong obstacle
    • No or few electrons pass through insulator
19. Slide 19

    Basic Terms

    • Please group these materials into correct category
    • Metal
    • Conductor
    • dry wood
    • Rubber
    • Wet wood
    • Glass
    • Insulator
    • Ceramic
20. Slide 20

    Basic Terms

    • Please group these materials into correct category
    • Metal
    • Ceramic
    • Glass
    • Wet wood
    • Rubber
    • Conductor
    • dry wood
    • Insulator
21. Slide 21

    Cable structures with conductors or insulators

    • Basic Terms
    • Copper
    • (conductor)
    • Plastic cable
    • (insulator)
    • Copper
    • (conductor)
    • Plastic
    • cable
    • (insulator)
    • Protective sheath
22. Slide 22

    Basic Terms

    • Electrical Circuit: a complete path of current
    • Voltage
    • Cable
    • (conductor)
    • Resistance
    • Open current conduction
    • path
    • can
    • stop
    • current
23. Slide 23

    Current always flows through least-resistant path Voltage

    • Basic Terms
    • Voltage
    • current
    • Resistance
    • Resistance
    • current
    • Switch
    • Switch
    • After closing the switch, all current flows through the switch due to its lower resistance
24. Slide 24

    Electrical Hazard Symbols

    • These symbols tell you if the situation in the picture is safe or not safe during this training.
    • Safe
    • Not safe
25. Slide 25

    A Case Study Discussion

    • Fallen Power Lines
    • A driver inside this car
    • Picture Source: https://www.youtube.com/watch?time_continue=317&v=fLVzvMTgGDY
    • A car hits an electricity pole, so downed power lines touch the car. A driver is inside of this car. Video -This Might Shock You: Downed Power Line
26. Slide 26

    A Case Study Discussion 1

    • Q1: Can people touch down power lines by hand?
    • Answer: No
    • Always assume that down power lines are live and energized
    • Transmission
    • Distribution
    • Subtransmission
    • 500Kv
    • 230Kv
    • 138Kv
    • 69Kv
    • 7-13Kv
27. Slide 27

    A Case Study Discussion 2

    • Q2: If people touch down power lines by skin, how much current will flow through a human body?
    • Video - Electrical Shock
    • Answer: assume the power line voltage is 7Kv
    • Human Body
    • Resistance
    • Current (assume 7Kv)
    • Wet skin
    • 1K ohms
    • 7 (unit: A)
    • Dry skin
    • 100~600K ohms
    • 11~70 (unit: mA)
28. Slide 28

    A Case Study Discussion

    • Consequences if current flow through human body
    • Current in Human
    • Body
    • Reaction
    • 5 mA
    • Wet or Dry hand
    • 6-25 mA (Women)
    • 9-30 mA (men)
    • Slight shock, not painful but disturbing; average individual can let go.
    • Painful shock, loss of muscular control Body freeze
    • 50-150 mA
    • Extreme pain, respiratory arrest, severe muscular contractions. Death is possible.
    • 1-4.3 A
    • Heart stop, muscular contraction, nerve damage, death likely
    • 10 A
    • Cardiac arrest, severe burns, death probable
29. Slide 29

    A Case Study Discussion 3

    • Q3: Can people touch down power lines by a stick, pole, or broom?
    • Answer: No
    • Not safe to use traditional non-conducting materials to touch power lines.
30. Slide 30

    A Case Study Discussion 4

    • Q4: Can the car driver touch car frame or metal parts?
    • Answer: No
    • Metal frame of the car would be charged with electricity
31. Slide 31

    A Case Study Discussion 5

    • Q5: What is safe distance from fallen power lines?
    • Answer: At least 35 feet (for voltage up to 750Kv)
    • ?? Feet
32. Slide 32

    A Case Study Discussion 6

    • Q6: If car starts fire, can the driver leaves?
    • Answer: Yes, but very carefully
    • Electricity spreads outward through the ground
    • Step potential creates large voltage differences to shock
    • Step
    • Potential
33. Slide 33

    A Case Study Discussion

    • Step potential
    • ΔV=V 1 -V 2
    • Voltage
    • Potential
    • Distribution
    • V 1
    • V 2
    • The Point of Touch
    • Step size: 1 feet
    • Step voltage could be up to 744 V, assume the potential of the point of touch is 5.7 KV
34. Slide 34

    A Case Study Discussion 7

    • Q7: How to leave car without electrical shocks? Answer: Small step for little step potential
    • Shuffle away
    • No large step
    • Shock resistance
    • More Details
    • shoes
    • Put hands at your sides, jump completely.
    • No touch car and ground at the same time.
    • Put feet together, take tiny steps without lifting feet .
35. Slide 35

    A Case Study Discussion 8

    • Q8: What distance is safely away from power lines?
    • Answer:
    • Depends on the power line voltage (see next slide)
    • ?? feet
    • 10 feet rule for voltage up to 50Kv
    • Always use maximum possible distance to avoid accidental touch
36. Slide 36

    A Case Study Discussion

    • Voltage (nominal,
    • Kv, alternating current)
    • <=50
    • 50-200
    • 200-350
    • 350-500
    • Minimum clearance distance (feet)
    • 500-750
    • 750-1000
    • >1000
    • Determined by utility owner/operator or a registered professional engineer
37. Slide 37

    A Case Study Discussion

    • Date
    • Place
    • What happen?
    • Injury
    • A boom truck contacted
    • December
    • Michigan overhead power lines
    • 2018
    • Electrocuted
    • (died)
    • North A boom truck contacted Carolina overhead power lines
    • Electric
    • Shocked (died)
    • May 2018
38. Slide 38

    A Case Study Discussion

    • Date
    • July 2018
    • June, 2018
    • Place
    • Ohio
    • Kentucky
    • What happen?
    • Injury
    • A crane touched a power line
    • Electrocuted
    • (died)
    • A dump truck struck power lines, the driver got out of the truck and was electrocuted.
    • He tried to help the truck driver.
    • (died)
    • Shocked
39. Slide 39

    Other Reported Accidents

    • Source: https://www.osha.gov/pls/imis/accidentsearch.search
    • Event Description
    • Employee touches aluminum ladder to overhead power line
    • Employee is electrocuted and killed after touching live power lines
    • Employee is found unresponsive and may have been electrocuted
    • Employee comes into contact with power line while trimming
    • Employee is shocked when comes into contact with live power lines
    • Employee touches live energized parts within a power generator
40. Slide 40

    Training Modules Agenda

    • Section 1: Basic Terms and Case Study
    • Section 2: Electrical Hazards (BESAFE)
    • Electrical Burn
    • Electrocution
    • Electrical Shock
    • Electrical Arc Flash
    • Electrical Fire
    • Electrical Explosion
    • Section 3: Electrical Incidents in Construction
    • Section 4: Electrical Hazards Prevention
41. Slide 41
    • Warning: The pictures in next few slides deal with injuries and death related to electrical accidents and might be disturbing to some people.
42. Slide 42

    Electrical Burn

    • Most common
    • shock-related injury
    • Electrical energy is
    • transformed into heat
    • Source: OSHA’s Electrical Incidents eTool
    • Immediate medical
    • attention is needed
    • Don’t wear jewelry
    • (ring, necklace, bracelet )
43. Slide 43

    Electrical Burn

    • Burns around current entrance point
    • Entrance Wound
    • Burns around current exit point
    • Exit Wound
    • An accident report Source: OSHA’s Electrical Incidents eTool
    • Two workers troubleshoot power outage. Worker #1 was holding a flashlight while worker #2 tested a 7,200 volt transformer. Worker #1 came close to or contacted live electrical parts, and was burned to arm, hand, and chest.
44. Slide 44

    Electrocution

    • A serious injury caused by electrical shock
    • 71 workers died from electrocution in 2017
    • 7.3% of total deaths in construction in 2017
    • Video - What Really Happe ns To Your Body When You 're Electrocuted?
    • Source: OSHA’s Focus-four
45. Slide 45

    Electrical Shock

    • Low voltage does not imply low hazard
    • Electrical shock injury depends on
    • current path
    • current amount
    • body contact time
    • Source: OSHA’s Electrical Incidents eTool
    • What is the most dangerous path for electricity shock through body? Head, Heart, or feet?
    • Answer: Heart. A current of 50mA flowing through heart triggers cardiac arrest
46. Slide 46

    Electrocution

    • If current > 75mA, death occurs in few minutes if no defibrillator in use
    • 75 mA is not much current – a small power drill uses 30 times as much current as killing current
    • Worst case: current flows through heart
    • Defibrillator in use
47. Slide 47

    Electrical Shock

    • Electricity travels in closed circuits.
    • Shock results when the body becomes part of the electrical circuit.
    • current
    • current
    • ground
    • Touches both wires of a circuit
    • Touches ground and one wire of a circuit
    • current
    • ground
    • Touches ground and a faulted energized appliance
48. Slide 48

    Electrical Shock

    • Electric current leaves intended path and travels through ionized air to one conductor, or to ground
    • Could happen by carelessly touching electrical equipment or switches
49. Slide 49

    Electrical Arc Flash

    • What causes an electrical arc flash?
    • Accidental contact
    • Equipment failure due to poor maintenance Faulty installation
    • Material failure or corrosion
    • Release of heat, bright light, gases, vapors
50. Slide 50

    Electrical Arc Flash

    • An accident report
    • Employees changed out a breaker in a 480-volt, 2000-amp, 3-phase system that was not de-energized. Employees did not wear PPE to protect from arc flash. One employee shorted out the system when his wrench, while connecting a conductor to one leg of the three phases, causing a short circuit and subsequent arc flash. The employee died.
51. Slide 51

    Electrical Arc Flash

    • OSHA requires warning labels in energized equipment
    • OSHA Regulation: 1926.403, 1926.416
    • Warning
    • Arc Flash Hazard
    • Appropriate PPE Required
    • Failure to Comply can
    • Result in Death or Injury
    • Switchboards
    • Panel boards
    • Industry control panels
    • Disconnect switches
52. Slide 52

    Electrical Fire

    • Possible reason: insulation jacket of cords is broken
    • Cords run through sharp objects, doors or windows
    • Damage insulation jacket of cords
    • Sparks or over-heat for fire
53. Slide 53

    Electrical Fire

    • Do not put water on electrical fire
    • electricity spreads to workers (electrical shock)
    • Video - Electrical Fire
    • Which fire extinguishers are for electrical fire?
    • Dry
    • Chemical
    • Powder
    • Carbon Dioxide
    • Water
    • Foam
54. Slide 54

    Electrical Explosion

    • Sudden release of energy when electricity ignites an explosive mixture of material
    • Heat radiation, pressure wave
    • Molten or fragmented metal flies in all directions
    • Video - Electrical Explosion
    • Picture Source: https://www.youtube.com/watch?v=cH9Zfq6zjgY
55. Slide 55

    Training Modules Agenda

    • Section 1: Basic Terms and Case Study
    • Section 2: Electrical Hazards (BESAFE)
    • Section 3: Electrical Incidents in Construction
    • Contact with Power Lines
    • Lack of Ground-Fault Protection
    • Path to Ground Missing or Discontinuous
    • Equipment Not Used in Manner Prescribed
    • Improper Use of Extension or Flexible Cords
    • Contact with Energized Sources
    • Section 4: Electrical Hazards Prevention
56. Slide 56

    Incident 1: Contact with Power Lines

    • Q9: What are potential electrical hazards below?
    • Overhead Power Line
    • Sand pile
    • Water gun or hose
    • Answer:
    • Never spraying water near power lines.
    • A circuit may be formed and shock persons
57. Slide 57

    Incident 1: Contact with Power Lines

    • Q10:What are potential electrical hazards below?
    • Painting
    • Building
    • Power Line
    • Lift Basket
    • Answer: possible contact with power line, fall hazard
58. Slide 58

    Incident 1: Contact with Power Lines

    • Q11: Are power lines well insulated to prevent electric shock?
    • Answer: No. Power lines are not insulated.
    • A bird safely stop on power lines, because it always perches on a single wire, and its two feet are at the same electrical potential so no current being formed.
59. Slide 59

    Energized vs. Deenergized Work

    • Energized Work Methods
    • Insulating gloves
    • insulating live line tools
    • Live line/bare hand techniques
    • Insulating Protective Equipment (IPE)
60. Slide 60

    Energized vs. Deenergized Work

    • Helicopter Transfering Lineman to Wire
61. Slide 61

    Incident 1: Contact with Power Lines

    • Video - Electrocution/Work Safely with La dders Near Power Lines
62. Slide 62

    Incident 2: Lack of Ground-Fault Protection

    • Current flows through an unintended path (human body) to ground
    • Energized Tool
    • current
    • Ground-Fault
    • ground
63. Slide 63

    Incident 2: Lack of Ground-Fault Protection

    • Video - What is Ground? Earth Ground/Earthing
64. Slide 64

    Incident 2: Lack of Ground-Fault Protection

    • Below show examples of good or bad grounding
    • Improper Grounding
    • Proper Grounding
65. Slide 65

    Incident 2: Lack of Ground-Fault Protection

    • When receptacles are not protected by GFCI
66. Slide 66

    Incident 3: Path to Ground Missing or Discontinuous

    • Ground path is loose or broken
    • prong missing
    • prong loose
    • OSHA Regulation: 1926.405
67. Slide 67

    Incident 3: Path to Ground Missing or Discontinuous

    • Q12: If bottom 3-prong outlet is occupied, break the ground pin of plug to fit 2-prong outlet?
    • 2-prong outlet
    • 3-prong plug
    • 3-prong outlet
68. Slide 68

    Do Not use hand-held non-double-insulated electric tools Dangerous !

    • Incident 3: Path to Ground Missing or Discontinuous
    • Faulty current
    • may travel through a worker’s body
    • Drill
    • Circular Saw
    • Grinder
    • ON
    • OFF
    • Planer
    • Sander
69. Slide 69

    Incident 4: Equipment not Used in Manner Prescribed

    • No use damaged electric
    • tools or worn cords
    • OSHA Regulation: 1926.405
    • No use indoor only
    • equipment outdoors
    • Plug
    • Caution: Indoor use only
    • Grinder
70. Slide 70

    No use wrong-rating circuit breakers or fuses for over-current protection

    • Incident 4: Equipment not Used in Manner Prescribed
    • OFF OFF OFF OFF
    • ON
    • ON ON
    • ON
    • Circuit Breaker Box
71. Slide 71

    Incident 5: Improper Use of Extension or Flexible Cords

    • For temporary use, not for permanent wiring
    • Cords are improperly wired directly to circuits
    • GFCIs should be used for fault protection
72. Slide 72

    No use extension or flexible cords in moisture or wet places

    • Incident 5: Improper Use of Extension or Flexible Cords
    • Bathrooms
    • Kitchens
    • Basements
    • Laundry room
73. Slide 73

    Incident 6: Contact with Energized Sources

74. Slide 74

    Training Modules Agenda

    • Section 1: Basic Terms and Case Study
    • Section 2: Electrical Hazards (BESAFE)
    • Section 3: Electrical Incidents in Construction
    • Section 4: Electrical Hazards Prevention
    • Maintain Safe Distance from Overhead Power Lines
    • Use Ground-Fault Circuit Interrupters (GFCI)
    • Inspect Portable Tools and Extension Cords
    • Use Power Tools and Equipment as Designed
    • Follow Lockout/Tagout Procedures
    • Personal Protective Equipment
    • Isolate Electrical Parts
75. Slide 75

    Maintain Safe Distance from Overhead Power Lines

    • OSHA Regulation: 1926.600; 1926.416
76. Slide 76

    Maintain Safe Distance from Overhead Power Lines

    • OSHA Regulation: 1926.600; 1926.416
77. Slide 77

    Maintain Safe Distance from Overhead Power Lines

    • Contact utilities to de-energize overhead or buried power lines
    • OSHA Regulation: 1926.961
78. Slide 78

    Maintain Safe Distance from Overhead Power Lines

    • Use non-conductive
    • wood or fiberglass ladder
    • Put warning signs
    • OSHA Regulation: 1926.1408
    • OSHA Regulation: 1926.1053
79. Slide 79

    Maintain Safe Distance from Overhead Power Lines

    • Survey construction site
    • No materials/equipment placed under power lines
    • OSHA Regulation: 1926.850
    • OSHA Regulation: 1926.1408
    • Power Lines
80. Slide 80

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • A GFCI is a circuit breaker which shuts off power when it senses ground faults
    • Test and reset every
    • GFCI before you use
    • OSHA Regulation: 1926.404
    • Reset Button
    • Test Button
81. Slide 81

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • Types of GFCIs for construction applications
    • Receptacle type Portable type
    • Cord-connected type
    • OSHA Regulation: 1926.404
82. Slide 82

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • Use GFCIs on all 120-volt, single-phase, 15-and 20-ampere receptacles
    • Always use GFCIs in flexible or extension cords
    • OSHA Regulation: 1926.404
83. Slide 83

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • OSHA’s Regulation for Construction Industry
    • 1926.404(b)(1)(ii) Ground-fault circuit interrupters. All
    • 120-volt, single-phase 15- and 20-ampere receptacle outlets on construction sites, which are not a part of the permanent wiring of the building or structure and which are in use by employees, shall have approved ground-fault circuit interrupters for personnel protection.
84. Slide 84

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • OSHA’s Regulation for General Industry
    • 1910.304(b)(3)(ii) Ground-fault circuit interrupters. All
    • 125-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are not part of the permanent wiring of the building or structure and that are in use by personnel shall have
    • ground-fault
    • circuit-interrupter
    • protection
    • for
    • personnel.
85. Slide 85

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • Circuit Breaker vs. GFCI
    • Operation
    • What to Protect
    • Circuit Breaker
    • GFCI
    • Automatic
    • Electrical circuit
    • Automatic Human body
    • Current imbalance
    • Damaged caused between going to
    • What hazards to by overload or and returning from
    • Protect
    • short circuit
    • electrical
    • equipment
86. Slide 86

    Use Ground-Fault Circuit Interrupters (GFCIs)

    • Use double-insulated hand-held tools
    • OSHA Regulation: 1926.302
    • Double Insulation Symbol
    • Non-conducting plastics
    • No metallic case
    • Reduce ground-fault risk and avoid electrical shocks
87. Slide 87

    Use Grounding Rod

    • Enable a low-resistance path to the earth
    • Fault current does not flow through human body
    • OSHA Regulation: 1926.962
    • Grounding
    • Rod
    • Ground Clamp
    • 6-8 feet deep
    • Energized Tool
    • Ground-
    • Fault
    • Ground Soil
88. Slide 88

    Inspect Portable Tools and Extension Cords

    • OSHA Regulation: 1926.1412
    • Visually inspect electrical equipment before use
    • Take any defective equipment out of service
    • If there any cracks or broken?
    • Damaged insulation in flexible cords
89. Slide 89

    Inspect Portable Tools and Extension Cords

    • Inspect frayed, cut, or broken wires
    • Exposed metal in damaged cords is dangerous
    • No repair cords with tape
    • OSHA Regulation: 1926.1412
90. Slide 90

    Inspect Portable Tools and Extension Cords

    • OSHA Regulation: 1926.416
    • No cords through sharp objects
    • Keep cords far way from nails, staples, screws
    • Do not run extension cords across walkways
91. Slide 91

    Inspect Portable Tools and Extension Cords

    • American wire gauge (AWG) measures wire size or diameter
    • Electrical
    • AWG Current
    • Rating
    • 13 A
    • 20 A
    • 30 A
    • 8 6
    • 40 A 55 A
    • Typical Usage
    • Extension cords Small appliances Window HVAC, clothes dryers Central HVAC Electric Furnace
92. Slide 92

    Inspect Portable Tools and Extension Cords

    • Choose right wire size
    • Under-sized wire
    • Excessive power loss
    • Temperature heats up for fire risk
    • Do not overload the socket
    • OSHA Regulation: 1926.405
93. Slide 93

    Inspect Portable Tools and Extension Cords

    • OSHA requires flexible cords to be rated for hard or extra-hard
    • Hard codes: S, ST, SO, STO, SJ, SJO, SJTO
    • OSHA Regulation: 1926.405
94. Slide 94

    Use Power Tools and Equipment as Designed

    • Use only equipment that is approved to meet
    • OSHA standards
    • Use all equipment according to manufacturer’s instruction
    • Remove damaged tools from use
    • OSHA Regulation: 1926.1417
95. Slide 95

    Use Power Tools and Equipment as Designed

    • Q13: Should you pull the plug or the cable?
    • Plug
    • Cable
    • Answer: When you disconnect the power plug from the outlet, always pull the plug (not the cable).
96. Slide 96

    Use Power Tools and Equipment as Designed

    • Use correct-rating circuit breakers or fuses for over-current protection
    • 30-amp circuit breaker
    • 15-amp receptacle
    • OSHA Regulation: 1926.449
    • No overload protection because it will not trip
97. Slide 97

    Use Power Tools and Equipment as Designed

    • Temporary lighting
    • Receptacles shall be of
    • the grounding type.
    • Be equipped with heavy duty electric cords
    • OSHA Regulation: 1926.405
98. Slide 98

    Use Power Tools and Equipment as Designed

    • Temporary lighting
    • Do not suspend by their electrical cords
    • Cords must be protected from damage, bulbs must be guarded
    • Must be equipped with overcurrent protection such as fuses or circuit breakers
    • OSHA Regulation: 1926.405
99. Slide 99

    Follow Lockout/Tagout Procedures

    • Apply locks to power source after de-energizing
    • Tag deactivated controls
    • OSHA Regulation: 1926.417
100. Slide 100

     Follow Lockout/Tagout Procedures

     • Tag de-energized equipment and circuits at all points where they can be energized
     • Tags must identify equipment or circuits being worked on
     • OSHA Regulation: 1926.417
101. Slide 101

     Follow Lockout/Tagout Procedures

     • Video - Case Study: Overhead Crane Se rvicing and Maintenance
102. Slide 102

     Personal Protective Equipment

     • Wear proper personal protective equipment (PPE)
     • Safety glasses
     • Face shields
     • Insulating gloves
     • Insulating sleeves
     • Safety shoes
     • Hard hats
     • Flame resistant clothing
     • OSHA Regulation: 1
     • OSHA has special PPE
     • 926.28
     • requirements for electrical hazards 1926.100
103. Slide 103

     Personal Protective Equipment

     • NFPA 70E is an standard for electrical safety
     • NFPA (National Fire Protection Association)
     • Help avoid injuries and fatalities due to electrical hazards
     • OSHA approaches NFPA 70E from both a standards perspective and an enforcement perspective.
     • Assist in complying with OSHA 1910 Subpart S and OS HA 1926 Subpart K
104. Slide 104

     2018 edition of NFPA

     • 70E: Table 1307.(C)(15)
     • (c)
105. Slide 105

     Personal Protective Equipment

     • Not any PPE device works for everyone
     • OSHA Regulation: 1926.28, 1926.100
     • For example, types of hard hats
     • Class of Hard Hat
     • Electrical Voltage Protection
     • Class G (General)
     • 2,200 volts
     • Class E (Electrical)
     • 20,000 volts
     • Class C (Conductive)
     • No electrical hazards protection
     • OSHA PPE Requirement
106. Slide 106

     Do not wear metal hard hats near electrical lines

     • Personal Protective Equipment
     • Class C Hard Hat
     • Class E/G Hard Hat
     • OSHA Regulation for Hard Hat Usage: 1926.100
107. Slide 107

     Personal Protective Equipment

     • A label of certification shows its class type
     • Class C Hard Hat
     • Class A/B Hard Hat
108. Slide 108

     Isolate Electrical Parts

     • Use guards or barriers
     • Replace covers
     • Guard live parts of electric equipment operating at 50 volts or more against accidental contact
     • Class
     • C Hard
     • Hat
     • OSHA
     • Regulation:
     • 1926.403(i)(2)(i)
     • Class A/B Hard Hat
109. Slide 109

     Isolate Electrical Parts

     • Conductors going into them must be protected, and unused openings must be closed.
110. Slide 110

     Isolate Electrical Parts

     • Junction boxes, pull boxes, and fittings must have approved covers
     • Unused openings in boxes, cabinets, and fittings must be closed
     • OSHA Regulation: 1926.405(b)(2)
111. Slide 111

     Training Modules Summary

     • Hazard Recognition
     • Prevention Methods
     • Contact with power lines
     • Effective safety training
     • Lack of ground-fault Inspect all tools before use
     • No touch fallen power lines
     • protection
     • Path to ground missing or Proper grounding
     • Use GFCIs with all tools
     • discontinuous
     • Equipment not used in
     • Lockout or tagout
     • Proper use of flexible cords
     • manner prescribed
     • Improper use of extension Do not use damaged tools
     • No work in wet conditions
     • and flexible cords
     • Contact with energized Wear PPE
     • Isolate electrical parts
     • sources
112. Slide 112

     Training Modules Summary

     • Worker to Build a Safe Working Environment
     • Good sense and aware of electrical hazard recognition
     • Don’t work alone, multiple workers together
     • Don’t work overtime to make your body tired
     • Only work on the tasks that a worker is qualified
     • Pre-job hazard analysis (OSHA booklet)
113. Slide 113

     Training Modules Summary

     • Job hazard analysis form from OSHA booklet
114. Slide 114

     Training Modules Summary

     • Worker to Build a Safe Working Environment
     • Lock out or tag out active circuits and equipment
     • Inspect and test circuits before using them
     • Know what to do if an electrical accident occurs
     • Know how to shut off to de-energize equipment
     • Know the location for circuit switches or breakers
115. Slide 115

     Case Study

     • What electrical hazards can you find below?
116. Slide 116

     Case Study

     • What electrical hazards can you find below?
     • Tr a ffic ligh ts
117. Slide 117

     Case Study

     • What electrical hazards can you find below?
118. Slide 118

     Case Study

     • A w or ker cou ld
119. Slide 119

     Case Study

     • What electrical hazards can you find below?
120. Slide 120

     Case Study

121. Slide 121

     Case Study

     • What electrical hazards can you find below?
122. Slide 122

     Case Study

     • Openings not closed
     • Panel boards have no dead front
     • No GFCI
     • Boxes not covered
     • System not grounded
123. Slide 123

     Case Study

     • What electrical hazards can you find below?
124. Slide 124

     Case Study

     • Distance between scaffold and power line less than 10 feet
125. Slide 125

     Case Study

     • What electrical hazards can you find below?
126. Slide 126

     Case Study

     • Damaged extension cord
     • Use 3-prong plug in 2-prong outlet, no grounding
127. Slide 127

     Case Study

     • What electrical hazards can you find below?
128. Slide 128

     Case Study

     • Ground pin is missing
129. Slide 129

     Case Study

     • What electrical hazards can you find below?
130. Slide 130

     Case Study

     • Flexible cords pass through doorway
     • (a pinch point)
131. Slide 131

     Case Study

     • What lessons do we learn from this accident?
     • A construction worker is manually digging holes, and the project stops due to rain. After the rain stops, the worker returns to dig. Because the electrical wire that is connected to a pull box is not protected, the insulation layer of wire is abraded by the pull box, causing the pull box, lifting machine, wire rope, and bucket to be charged. The worker carried out construction without any inspection. When he touched the charged bucket, he was subjected to a strong electric shock and died.
132. Slide 132

     Case Study

     • Workers spray solar panels for cleaning on wet building roof. Workers stand on a roof, they have the same elevation as power lines
     • 12Kv High Voltage Lines
     • Aluminum pole
     • Worker #2
     • Spray
     • Any potential electrical hazards?
     • Worker #1
133. Slide 133

     Any Questions?

134. Slide 134

     Post-Test

     • Please Begin Post-Test (15 Minutes)
135. Slide 135

     Feedback Survey

     • Please fill in the feedback survey
     • (Hand in the training package to the trainer)
136. Slide 136

     Post-Test Solution

     • Interactive Post-Test Q/A Session
137. Slide 137

     The End

     • Thank you!