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					Electrical Hazards Awareness

  Basic Electrical Safety Hazard Awareness for
            Non-Electrical Personnel

                      Module 1

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•   The purpose – worker safety
      Raising your awareness of electrical hazards
      Instructing you on how to recognize electrical hazards
      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

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• An average of one worker is electrocuted on the job every
• 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

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       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

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              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

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

 * mA = milliampere = 1/1,000 of an ampere

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How is an electrical shock received?

• When two wires have different potential differences
  (voltages), current will flow if they are connected
    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

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How is an electrical shock received?

• 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 electrocuted

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 Low Voltage Does Not Mean Low
• 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
• Deaths from 120 volts represent about 12 percent of
  all electrocutions

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

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                 Recognize the Hazards
                                   Have you seen areas like these?

    Both are NEC violations and present a safety hazard, based on inaccessible circuit control devices
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
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             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
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       Recognize the Hazard

• Assume all exposed wiring
  is energized until proven
  otherwise. STOP, protect
  the area and contact
  supervision if you
  encounter this situation

                           exposed wire
                             with status
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       Recognize the Hazard
  Tripping and Abrasion Hazards
                             Not OK                            OK
• Don’t cause tripping
  hazards or create
  pinch points for
• If you must run a
  cord temporarily
  across the floor,
  protect your co-
  workers by
  covering the cord

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           Recognize the Hazards
Remove from service damaged or frayed cords
Report electrical equipment damage to your supervisor

                                                    •   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
                                                    •   Electrical cords that are worn or
                                                        damaged must be replaced without
                                Stay clear of           delay.
                                                    •   Before cleaning electrical equipment,
                                bare, exposed
                                                        turn it off and unplug it.
                                wiring and
                                REPORT IT!

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       Recognize the Hazard
    Cabinets, Boxes, and Fittings
• 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

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Recognize the Hazards

Never daisy chain multi-outlet strips (plugging into each other)

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          Recognize the Hazard

• Observe all barricades,
  postings, and warning
  signs regarding dangerous
• Do not enter or approach
  electrical work areas unless
  specifically authorized and

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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.

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            Recognize the Hazard
              Grounding 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

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         Recognize the Hazards
• Electrical hazards may exist                  Stay at least 10 feet away from overhead lines
  overhead indoors
    Crane power rails are an
• Electrical hazards may also
  exist overhead outdoors
    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
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       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

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               Recognize the Hazard

  • Treat it as it is
    designed to be
  • Pull the plug, not the

Handle portable electrical equipment carefully, in accordance with manufacturers
instructions, and in a manner that will not cause damage
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      Clues that Electrical Hazards
               May Exist
• Tripped circuit breakers or blown fuses
• Hot to the touch on tools, wires, cords, connections, or junction
• Dim and flickering lights
• Sizzles and buzzes-unusual sounds from electrical system
• 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 connection
• Burn marks or discoloration on receptacle plates or plug prongs

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    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
  E&I to troubleshoot if GFCI continues to trip.

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 Prohibited Uses of Flexible Cords

Substitute for   Run through walls,                Concealed behind
fixed wiring     ceilings, floors,                 or attached to
                 doors, or windows                 building surfaces

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                    Safe Practices
                     Cord 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

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            Safe Practices
          Cord 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 won’t stay placed snugly or fits loosely in a
  receptacle, don’t use it; call local E&I to replace it

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              Safe Practices
            Resetting Breakers
• When circuit breakers and fuses trip, don’t 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

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             Safe Practices
           Conductive Apparel
• Don’t wear loose
  conductive apparel,                       Charm
  (such as rings,                           plug
  watch bands,                              Burn
  bracelets,                                from arc

  necklaces, etc.)
  when plugging in
  electrical cords                           Charm
                                             contacted plug

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                 Safe Practices
                Wall 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
• 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

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                 Safe Practices
             Equipment 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,
•   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.

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                Safe Practices
• 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)

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       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

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          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

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           Electrical Emergencies
            Downed 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 together
    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 possible
    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

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                 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

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                  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
   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 documentation

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         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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Description: Electrical safety works guide, To ensure the safest worksite possible, common sense and safe work practices should be followed. Here are some recommended procedures and practices that will help in achieving this goal.