Transcript Electrical Safety On the Job

NUECES COUNTY
Electrical Safety
On the Job
Unqualified Worker
Session Objectives
Understand the hazards of electricity
Identify and avoid common electrical
hazards
Follow safe work practices around
electrical equipment
How Does Electricity Work?
Electrical Hazards
 Contact with power lines
 Contact with damaged
electrical equipment
 Improper wiring
 Overloading
 Unsafe work practices
Electrical Injuries
Cardiac arrest and
respiratory failure
Burns
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Muscle, nerve, and
tissue destruction
Secondary
injuries
Thermal burns
How Electrical Shock Occurs
Contact with:
 Electrical energy
 Two current-conducting wires
at different voltages
 An energized wire and a
grounded object
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Severity of Electrical Shock
 Amount of electrical current—higher
is more dangerous
 Duration—longer
is more dangerous
 Path through the
body—through
the heart is most
dangerous
Effects of Electrical
Current on the Body
0.5–3 mAmp
Faint, tingling
sensation
6–30 mAmp
Painful shock,
severe muscle
contractions ,
no muscle control
50–150 mAmp
Extremely painful
shock, respiratory
arrest, severe
muscle contractions,
death may occur
1–4 Amp
Ventricular
fibrillation, nerve
damage, death
is likely
10 Amp
Cardiac arrest,
severe burns,
death is probable
Injuries from
Electrical Shock
 Electrocution
 Injuries
 Secondary injuries
Arc Flash and Arc Blast
 Arc Flash—electricity
flows through the air
 Arc Blast—pressure
wave from an arc flash
Image Credit: OSHA
Electrical Burns
 Burns are a common
shock-related injury
 Electricity generates heat
in the body
 Thermal burns from
hot surfaces and fires
Electrical Burns (cont.)
Match the current to the body’s response
0.5 to 3 mAmp
Ventricular fibrillation; death likely
6 to 30 mAmp
Cardiac arrest; probable death
50 to 150 mAmp
1 to 4 Amp
10 Amp
Extremely painful shock;
possible death
Painful shock; loss of
muscle control
Faint, tingling sensation
Electrical Hazards—
Any Questions?
Do you understand:
 The hazards and
injuries of electricity in
the workplace?
Emergency Response and First Aid
for Electrical Shock




Do not touch!
Shut off electrical current
Call for help
Administer first aid
and CPR
Using an AED
 Helps treat ventricular
fibrillation
 Shocks the heart back to
normal rhythm
 Saves lives if used
properly
Stay Away from 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
 Don’t dig near buried lines
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Report and Don’t Use Damaged
Equipment
 Broken or missing covers
 Damaged tools
 Damaged cords
 Damaged equipment
Ensure Electrical
Equipment Is Grounded
 Exposed parts can become
energized
 Always ground electric tools
and equipment
 Path to ground must be
continuous
Circuit Protective Devices
 Circuit breakers trip
if overloaded
 Don’t reset unless
authorized
 Contact a qualified person
to investigate
Ground Fault Circuit Interrupter (GFCI)
 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 tested
periodically
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Follow Lockout/Tagout Procedures
 Devices that prevent access to
hazardous energy
 Lockout ensures equipment
isn’t accidentally restarted
 Tagout is used where lockout
is not feasible
Follow Safe Work Practices
Work on electrical equipment
only if qualified
Wear safety equipment
Illuminate work area
Use nonconductive ladders
Follow Safe Work Practices (cont.)
Don’t wear conductive apparel
Don’t use conductive liquids
Do not defeat electrical
interlocks
Use Portable Electrical Equipment Safely
 Inspect for damage
 Check cord and ground
 Don’t lift by cord
 Dry hands when plugging
and unplugging
 GFCI in wet locations
Stay Away from
Electrical Work Areas
 Electrical work areas need to
be isolated
 Alerting techniques
 Safety Signs and Tags
 Barricades
 Attendants
Only qualified personnel may work on or near
exposed energized equipment!
Safe Practices
Work on electrical
equipment if
qualified
Illuminate work
area
Wear conductive
apparel
Use nonconductive
ladders
Use conductive
liquids near
electricity
Defeat electrical
interlocks
Unsafe Practices
Safety Practices—
Any Questions?
Do you understand:
 First aid?
 Electrical equipment?
 Electrical circuits?
 Lockout/tagout?
 Safe work practices?
 The electrical safety
program?
Key Things to Remember
Exposure to electricity can be dangerous
Watch for electrical hazards
Follow safe work practices
Follow the electrical safety program
Seek assistance from a qualified person
If any further questions, contact
Risk Management Department