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Electrical Hazards Awareness Briefing


The purpose worker safety Raising your awareness of electrical hazards Instructing you on how to recognize electrical hazards Providing ways to eliminate, ... – PowerPoint PPT presentation

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Title: Electrical Hazards Awareness Briefing

Electrical Hazards Awareness Briefing
  • Basic Electrical Safety Hazard Awareness for
  • Non-Electrical Personnel
  • Module 1

  • The purpose worker safety
  • Raising your awareness of electrical hazards
  • Instructing you on how to recognize electrical
  • Providing ways to eliminate, remove and prevent
    electrical hazards in the workplace
  • Emphasizing the extreme importance of observing
    all electrical safety requirements and practices
  • Instructing you on what to do during an
    electrical accident

  • An average of one worker is electrocuted on the
    job every day
  • An average of one person is electrocuted in the
    home every 36 hours
  • Electrical incidents are far more likely to be
    fatal than other types
  • There are four main types of electrical injuries
  • Electrocution (death due to electrical shock)
  • Electrical shock
  • Burns
  • Falls

Electrical Terminology
  • Current the movement of electrical charge
  • Resistance opposition to current flow
  • Voltage a measure of electrical force
  • Conductors substances, such as metals, that
    have little resistance to electricity
  • Insulators substances, such as wood, rubber,
    glass, and bakelite, that have high resistance to
  • Grounding a conductive connection to the earth
    which acts as a protective measure

Electrical Shock
  • Received when current passes through the body
  • Severity of the shock depends on
  • Path of current through the body
  • Amount of current flowing through the body
  • Length of time the body is in the circuit

Dangers of Electrical Shock
  • Currents greater than 75 mA can cause
    ventricular fibrillation (rapid, ineffective
  • Will cause death in a few minutes unless a
    defibrillator is used
  • 75 mA is not much current a small power drill
    uses 30 times as much

Defibrillator in use
mA milliampere 1/1,000 of an ampere
How is an electrical shock received?
  • When two wires have different potential
    differences (voltages), current will flow if they
    are connected together
  • In most household wiring, the black wires are at
    110 volts relative to ground
  • The white wires are at zero volts because they
    are connected to ground
  • If you come into contact with an energized (live)
    black wire, and you are also in contact with the
    white grounded wire, current will pass through
    your body and YOU WILL RECEIVE A SHOCK

How is an electrical shock received?(contd)
  • If you are in contact with an energized wire or
    any energized electrical component, and also with
    any grounded object, YOU WILL RECEIVE A SHOCK
  • You can even receive a shock when you are not in
    contact with a ground
  • If you contact both wires of a 240-volt cable,
    YOU WILL RECEIVE A SHOCK and possibly be

Low Voltage Does Not Mean Low Hazard
  • A small amount of electrical current can cause
    injury, even death
  • The current from a 7.5-watt, 120-volt lamp,
    passing across the chest, is enough to cause
    fatal electrocution
  • Deaths from 120 volts represent about 12 percent
    of all electrocutions

Electrical Burns
  • Most common shock-related, nonfatal injury
  • Occurs when you touch electrical wiring or
    equipment that is improperly used or maintained
  • Typically occurs on the hands
  • Very serious injury that needs immediate

Recognize the Hazards
Have you seen areas like these?
Both are NEC violations and present a safety
hazard, based on inaccessible circuit control
Do not block the working space around electrical
equipment (600 volts, nominal, or less). This
space provides and maintains sufficient access
and working space to permit ready and safe
operation and maintenance of such equipment
Recognize the Hazards
What do you do if you see these situations?
Call a timeout and inform your supervisor
Do not remove or open receptacle covers, switch
plates, or covers of electrical equipment unless
qualified and authorized
Recognize the Hazard
  • Assume all exposed wiring is energized until
    proven otherwise. STOP, protect the area and
    contact supervision if you encounter this

Potentially energized exposed wire with status
Recognize the HazardTripping and Abrasion
Not OK
  • Dont cause tripping hazards or create pinch
    points for cords
  • If you must run a cord temporarily across the
    floor, protect your co-workers by covering the
    cord appropriately

Recognize the Hazards
Remove from service damaged or frayed
cords Report electrical equipment damage to your
  • Visually inspect electrical equipment before each
    use for damage and/or external defects such as
    loose, missing or deformed parts, pinched or
    crushed outer jackets or insulation. This type
    of external damage may indicate internal damage
    to the equipment.
  • Electrical cords that are worn or damaged must be
    replaced without delay.
  • Before cleaning electrical equipment, turn it off
    and unplug it.

Stay clear of bare, exposed wiring and REPORT IT!
Recognize the Hazard Cabinets, Boxes, and
  • Junction boxes, pull boxes and fittings must have
    approved covers in place
  • Unused openings in cabinets, boxes and fittings
    must be closed (no missing knockouts)
  • Photo shows violations of these two requirements
  • Report this situation to management

Recognize the Hazards
Never daisy chain multi-outlet strips (plugging
into each other)
Recognize the Hazard
  • Observe all barricades, postings, and warning
    signs regarding dangerous voltages
  • Do not enter or approach electrical work areas
    unless specifically authorized and qualified.

Recognize the Hazards
Not permitted and should be taken out of
service! Electrical boxes with knockouts are
designed to be installed in or on walls, not used
as multi-outlet extension cords.
Recognize the HazardGrounding Path
  • The path to ground from circuits, equipment, and
    enclosures must be permanent and continuous
  • Violation shown here is an extension cord with a
    missing grounding prong
  • Do not make alterations to polarized blades or
    ground pin to make plug fit into non-polarized or
    non-grounded outlet

Recognize the Hazards
  • Electrical hazards may exist overhead indoors
  • Crane power rails are an example
  • Electrical hazards may also exist overhead
  • Most lines are bare and higher voltage than the
    normal insulated wiring
  • Contact is not required to initiate an arc or
    cause shock and burn injuries
  • Maintain safe approach distances when working
    near energized overhead lines

Stay at least 10 feet away from overhead lines
Recognize the Hazard
  • Electrical equipment and wiring must not be
    exposed to physical damage
  • Picture shown here is physical damage to conduit
  • Stay away from damaged equipment and report
    equipment damage to supervision

Recognize the Hazard
  • Treat it as it is designed to be treated
  • Pull the plug, not the cord

Handle portable electrical equipment carefully,
in accordance with manufacturers instructions,
and in a manner that will not cause damage
Clues that Electrical Hazards May Exist
  • Tripped circuit breakers or blown fuses
  • Hot to the touch on tools, wires, cords,
    connections, or junction boxes
  • Dim and flickering lights
  • Sizzles and buzzes-unusual sounds from electrical
  • Odor of hot insulation
  • Mild tingle from contact with case or equipment
  • GFCI that shuts off a circuit
  • Worn or frayed insulation around wire or
  • Burn marks or discoloration on receptacle plates
    or plug prongs

Ground-Fault Circuit Interrupter
  • Always use a GFCI receptacle or circuit for cord
    connected tools and equipment used outdoors or
    near water
  • This device protects you from electrocution
  • The GFCI detects a difference in current between
    the black and white circuit wires
  • (This could happen when electrical equipment is
    not working correctly, causing current leakage
    known as a ground fault.)
  • Perform the test function on the GFCI to
    determine if it is functioning properly by
    pushing the button to verify it shuts off
  • Repeated resetting not allowed. Contact local
    EI to troubleshoot if GFCI continues to trip.

Prohibited Uses of Flexible CordsExamples
Substitute for fixed wiring
Run through walls, ceilings, floors, doors, or
Concealed behind or attached to building surfaces
Safe PracticesCord Control
  • Do not fasten electrical cords to surfaces with
    staples, nails, wire, or any other method that
    might damage the cord
  • Extension cords
  • Place them in appropriate locations
  • Understand they are for temporary use only
  • Tool cords
  • Keep track of them, to assure they do not become
  • Do not plug or unplug electrical cords with wet
    hands or while standing in water

Safe PracticesCord Control Cont.
  • Do not use portable electrical equipment or
    extension cords in wet or damp locations without
    a ground fault circuit interrupter (GFCI) ahead
    of the plug connection
  • GFCIs are also required for temporary power
    applications in wet or damp locations, including
    extension cords
  • Remove loads from an appliance or extension cord
    before unplugging it
  • If a plug wont stay placed snugly or fits
    loosely in a receptacle, dont use it call local
    EI to replace it

Safe PracticesResetting Breakers
  • When circuit breakers and fuses trip, dont reset
    or replace them!
  • Only qualified and authorized personnel are
    allowed to reset breakers and replace fuses
  • Contact qualified personnel to determine the
    cause of trips

Safe PracticesConductive Apparel
  • Dont wear loose conductive apparel, (such as
    rings, watch bands, bracelets, necklaces, etc.)
    when plugging in electrical cords

Charm contacted plug
Burn from arc
Charm contacted plug here
Safe PracticesWall Penetrations
  • When penetrating walls to hang pictures, bulletin
    boards, signs, understand and follow site
    requirements to ensure that concealed electrical
    wiring, conduit or piping will not be contacted
  • A non-obtrusive survey (e.g., Ground Penetrating
    Radar, proximity detection device) may be
    required, along with a review of applicable
    drawings, to ensure that the electrical system is
    not penetrated or contacted

Safe PracticesEquipment Applications
  • Consumer electrical equipment or appliances
    should be tested and labeled by a recognized
    testing laboratory. (Look for the UL, CSA, ETL or
    MET Label)
  • Always read and follow the manufacturers
    instructions carefully. Be sure that the
    equipment or tool is rated for the environment
    (wet, damp, etc.)
  • Plug portable space heaters directly into outlet
    Do not use extension cord. Use a circuit with as
    little else on it as possible since space heaters
    take a lot of power.

Safe PracticesQualifications
  • Do not remove/replace receptacle covers, switch
    plates, or covers of electrical equipment that
    may contain energized conductors without
    electrical qualifications and authorization
  • Only qualified electrical workers may perform
    activities such as electrical probing, measuring
    and testing electrical energized components (such
    as performing an absence of voltage test)

Electrical Emergencies
  • Do you know what dangers could be encountered?
  • Attempts to rescue an accident victim may pose as
    great a hazard for the rescuer as it does for the
  • A victim of an electrical accident is often
    unable to move or release the electrical
    conductor, because of muscle clamping
  • Caution should be a primary consideration during
    any electrical accident or emergency

Electrical Emergencies
  • Do you know the proper actions to take if you see
    someone receiving a shock or locked onto an
    energized electrical line?
  • Approaching the accident
  • Never rush into an accident situation-Assess your
    own safety
  • Call 911 as soon as possible
  • Unplug portable electrical equipment to remove
    power (1st choice)
  • Open a disconnecting device or circuit breaker to
    de-energize fixed electrical equipment
  • Use a dry wood broom, leather belt, plastic rope,
    or something similar that is non-conductive such
    as wood or plastic cane with hook on the end to
    free the person from the energy source

Electrical EmergenciesDowned Power Lines
  • Do you know the proper actions to take?
  • Approaching the accident
  • Move away from downed power line
  • Shuffle away with small steps keeping feet
  • If you see someone in direct contact with line,
    do not touch person
  • Call 911 as soon as possible
  • Do not attempt to move downed power line
  • Get the aid of trained electrical personnel if
  • If you are in your car and it is it contact with
    the downed line, stay in car. Honk horn for help
    and tell others to stay away from your vehicle

What Now?
  • Inspect your work areas
  • Existing unsafe conditions
  • Bare wires
  • Open enclosures containing exposed wires
  • Loose or missing covers or fasteners
  • Use good electrical safe practices
  • No daisy-chaining
  • No overloading outlets
  • Pull on plug, not cord

What Now?
  • What do I do if I identify a hazardous condition?
  • When unsafe electrical conditions are found,
    correct them if possible, or take steps to warn
    other employees
  • Report unsafe electrical conditions verbally
    and/or in writing to supervision so corrective
    actions can be taken immediately
  • Barricade the area, if an immediate hazard exists
  • Notify supervision for correction and

For More Information
  • Contact
  • Your Site Electrical Safety Officer, or
  • Your Safety Engineer
  • WEB Sites
  • See DOE Electrical Safety Campaign at
  • See Electrical Safety Foundation International at
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