Electrical Safety

1
Electrical Safety

• Unqualified Worker

2
Session Objectives

• You will be able to
• Understand the hazards of electricity
• Identify and avoid common electrical hazards
• Follow safe work practices around electrical
  equipment

3
How Does Electricity Work?

• Flow of electrons, similar to flow of water
  through a pipe
• Voltage Pressure
• Amperage Flow
• Resistance Restriction

4
Electrical Hazards

• Contact with overhead and buried power lines
• Contact with damaged electrical equipment
• Improper wiring
• Overloading
• Unsafe work practices

5
Electrical Injuries

• Cardiac arrest and respiratory failure from
  electrical shock or electrocution
• Muscle, nerve, and tissue destruction from
  current passing through the body
• Burns from arc flash and arc blast
• Thermal burns from contact with source
• Secondary injuries

6
How Electrical Shock Occurs

• Shockelectrical energy contacts your body
• Contact two wires or components at different
  voltages
• Contact an energized wire or component and a
  grounded object

7
Severity of Electrical Shock

• Severity depends on
• Amount of electrical currenthigher is more
  dangerous
• Durationlonger is more dangerous
• Path through the bodythrough the heart most
  dangerous

8
Effects of Electrical Current on the Body
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Injuries from Electrical Shock

• Electrocution
• Injuries
• Blood vessels, nerves, organs, and burns
• Secondary injuries
• Falls
• Trauma

10
Arc Flash and Arc Blast

• Arc Flashelectricity flows through the air
• Temperatures as high as 35,000 degrees,
  vaporizing metal
• Severe skin burns
• Arc Blastpressure wave from an arc flash
• Severe injuries from blast
• Facility and equipment damage

Image Credit OSHA
11
Electrical Burns

• Burns are a common shock-related injury
• Electricity generates heat in the body
• 2nd and 3rd degree
• Some severe burns appear minor on the outside
• Thermal burns from hot surfaces and fires

12
Electrical HazardsAny Questions?

• Any questions about the hazards and injuries of
  electricity in the workplace?

13
Emergency Response and First Aid for Shock

• If a person is shocked
• Do not touch the person during the shock event
• Shut off electrical current
• Call for help
• Administer first aid and CPR use AED

14
Stay Away from Power Lines

• Overhead power lines
• Stay at least 10 feet away
• Keep equipment at least 10 feet away
• Add 4 inches for every 10 kV over 50 kV
• Buried power lines
• Dont dig until verified that buried lines and
  other utilities are not in the area

15
Report and Dont Use Damaged Equipment

• Stop using and report
• Broken or missing covers
• Damaged tools
• Damaged cords
• Damaged equipment

16
Ensure Electrical Equipment Is Grounded

• If no safe path to ground, exposed parts can
  become energized
• Electric power-operated tools and equipment must
  be grounded or double-insulated
• Path to ground must be continuous

17
Ground Fault Circuit Interrupter (GFCI)

• GFCIs detect current between the two circuit
  wires
• Trip at about 5 mAmp
• Can get a shock before it trips
• If it keeps tripping there is a problem
• Need to be periodically tested

18
Follow Lockout/Tagout Procedures

• Devices that prevent access to hazardous energy
• Lockout ensures equipment isnt accidentally
  restarted
• Tagout used where lockout not feasible
• Follow lockout/tagout program procedures

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Follow Safe Work Practices

• Only qualified persons may work on or near
  exposed electrical equipment and wiring
• Dont wear conductive apparel
• Work area must be illuminated
• Dont allow conductive liquids near electrical
  work or equipment
• Do not defeat electrical interlocks
• Use nonconductive ladders

20
Use Portable Electrical Equipment Safely

• Inspect for damage
• Check cord and ground
• Use safely
• Dont lift by cord
• Dry hands when plugging and unplugging
• GFCI in wet locations

21
Circuit Protective Devices

• Circuit breakers and fuses are designed to trip
  if overloaded
• Dont reset unless authorized to do so
• Contact a qualified person to investigate

22
Stay Away from Electrical Work Areas

• Electrical work areas need to be isolated
• Alerting Techniques
• Safety Signs and Tags
• Barricades
• Attendants

23
Follow the Electrical Safety Program

• Written procedure includes
• Responsibilities
• Procedures
• Safe work practices
• Personal protective equipment
• Only qualified personnel may work on or near
  exposed energized equipment!

24
Safety PracticesAny Questions?

• Any questions about
• First aid?
• Electrical equipment?
• Electrical circuits?
• Lockout/tagout?
• Safe work practices?
• The electrical safety program?

25
Key Things to Remember

• Exposure to electricity can cause electrocution,
  shock, electric and thermal burns, arc flash and
  arc blast burns, and secondary injuries
• Watch carefully for electrical hazards
• Follow safe work practices, including emergency
  response procedures
• Follow the electrical safety program
• Seek assistance from a qualified person