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ELECTRICAL SAFETY AWARNESS TRAINING

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Responsible for the condition of plug and cord of equipment ... periodically test it by plugging something into it and pushing the 'test' button. ... – PowerPoint PPT presentation

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Title: ELECTRICAL SAFETY AWARNESS TRAINING


1
ELECTRICAL SAFETY AWARNESS TRAINING
Training Program
Updated 5/5/04
2
Electrical Fires in the USA
  • Daily, fires occur due to electrical problems
    defective electrical device, circuit overloading,
    circuit overheating, explosions ignited by
    electrical spark, etc.
  • Electricity is one of the most common causes of
    fire in the USA. Each year there are
    approximately
  • 1.6 million fires (all causes) reported,
  • causing 3,600 fire deaths,
  • 18,000 fire related injuries,
  • 10.7 billion in property damage.
  • Source National Fire Protection Association, 2007

3
Grounding
  • What is Grounding?
  • Grounding a tool or electrical system means
    intentionally creating a low-resistance path that
    connects to the earth. This prevents the buildup
    of voltages that could cause an electrical
    accident.
  • Grounding is normally a secondary protective
    measure to
  • protect against electric shock. It will
    substantially reduce the
  • risk of injury or death in case of shock,
    especially when used
  • in combination with other electrical safety
    measures.
  • An equipment ground helps protect the equipment
    operator.
  • It furnishes a second path for the current to
    pass through
  • from the tool or machine to the ground. This
    additional
  • ground safeguards the operator if a malfunction
    causes the
  • tools metal frame to become energized. The
    resulting flow
  • of current may activate the circuit protection
    devices.

4
Protection
  • Overcurrent Protection
  • Fuses and circuit breakers open/break the circuit
    automatically when too much current flows through
    them.
  • This is designed to protect the wiring/equipment
    from overheating and possible damage NOT THE
    USER
  • GFCI (Ground Fault Circuit Interrupter)
  • Used in wet and other high-risk areas.
  • Stops the flow of electricity when there is
  • a difference between current leaving and
  • returning from the outlet.
  • Should be tested monthly
  • Push test button and then the reset button

5
Power Extension Cords and Power Strips
  • Extension Cords Power Strips are for TEMPORARY
    use only!
  • They may not be run through doorways, ceilings or
    windows
  • Power Strips (Transient Voltage Surge
    Suppressors)
  • FOR ELECTRONICS ONLY (Computer Equipment etc.)
  • NOT FOR APPLIANCES (Refrigerator, Microwave
    Toaster, Coffee Pot, Water Cooler etc.)
  • Do not overload
  • The number of outlets on the power
  • strip does not indicate how many
  • devices can be connected

12
6
Properly Used Power Strip
  • EXAMPLES OF A PROPERLY
  • USED POWER STRIP
  • STRIP IS NOT OVERLOADED
  • ONLY COMPUTER (ELECTRICAL) EQUIPMENT IS ATTACHED
    TO STRIP
  • CORDS ARE KEPT NEAT
  • NO EXTENSION CORDS ARE ATTACHED TO POWER STRIP
  • POWER STRIP IS ATTACHED DIRECTLY TO WALL
    OUTLET-NO EXTENSION CORD IS USED

7
Improperly Used Power Strip
  • EXAMPLES OF AN IMPROPERLY
  • USED POWER STRIP
  • POWER STRIP IS OVERLOADED DUE TO MINI-FRIDGE,
    MICROWAVE, AND TWO-POT COFFEE MAKER ALL ON ONE
    POWER STRIP
  • APPLIANCES ARE CONNECTED TO A POWER STRIP (THEY
    SHOULD BE CONNECTED DIRECTLY INTO A WALL OUTLET)
  • POWER STRIP IS NOT CONNECTED DIRECTLY TO THE WALL
    OUTLET - AN EXTENSION CORD IS USED

EXTENSION CORD IS USED WITH POWER STRIP
8
Damaged and Unapproved Devices
Not Permitted
Cord plug with ground prong missing
Damaged TVSS rated power strip
Adapter enables circuit overload
9
Damaged and Unapproved Devices
Not Permitted
Lamp extension cord, also damaged
Power taps
Adapter to change 3-prong plug to 2-prong
eliminating ground
10
Container Bonding and Grounding(Static
Electricity)
Bonding Cable
Grounding Cable
Grounding Bus
or Electrode
7
  • Proper grounding and bonding is used to address
    the dangers of static electricity.
  • In order for grounding to protect, all surfaces
    must be bonded together and grounded to earth.
  • Static electricity is thereby released to earth
    as it is generated, preventing the accumulation
    of dangerous charges that may ignite flammable /
    hazardous substances.

11
Responsibilities
  • Entire system must be properly bonded and
    grounded to the earth
  • Facilities
  • Responsible for the system up to the wall outlet
    (all wiring and outlets)
  • User
  • Responsible for the condition of plug and cord of
    equipment
  • Inspect equipment to ensure plugs and cords are
    not damaged.
  • Do not break off third prong or use adaptors
  • No Prong Not Grounded

12
Electrical Safety Incidents
  • The following is an example of
  • Electrocution Due to Improper Use of Common
    Equipment

13
Background
  • Dr. X was conducting an experiment related to
    plant growth.  He needed to expose the plants to
    light for specific time-periods each day.  
    Accordingly, he had a portable fluorescent
    lighting rack constructed and mounted on a wooden
    frame.  He also obtained an electric timer to
    automatically turn the lights on and off. The
    light fixture was plugged into the timer, which
    was plugged into the wall outlet.  However, since
    the timer only accepted a two prong plug, an
    adapter was used to allow the three prong plug of
    the lighting rack to be used with the two prong
    outlet of the timer.

14
The Incident
  • Dr. X adjusted the timer so that the lights
    would be on and plugged the timer into a standard
    3-prong wall outlet.  Then another person in the
    lab noticed Dr. X grasping the lighting rack and
    appearing to be rigid.  A third person grasped
    Dr. X by the shoulders and pulled him away from
    the lighting rack.  CPR was performed on him
    until EMS arrived.  Dr. X was transported to a
    hospital where he was pronounced dead.

15
The Investigation
  • The investigation revealed the following details
  • A potential difference of 397 volts was measured
    between the metal fluorescent light fixture and
    the adjacent stainless steel sink.  (There should
    not have been any potential difference).    
  • Both the fixture and the wall outlet were found
    to be wired correctly.
  • The light fixture was rated for 800 mA, but the
    lamps used were 1500 mA.
  • The transformer in the ballast was found to have
    short circuited to the case.

16
What Probably Happened
  • Use of bulbs drawing more current than approved
    for the fixture caused overheating of the ballast
    resulting in melting of insulation around the
    transformer coil.  This allowed an energized
    transformer wire to touch the metal cover of the
    ballast which in turn energized the metal
    fluorescent fixture.  The lights probably
    continued to function since they were wired
    correctly.When Dr. X grasped the fixture, some
    part of him probably brushed against the nearby
    metal sink.  This completed a circuit to ground
    through Dr. X, electrocuting him.

17
Preventing this Fatality
  • As with many very serious accidents, a number of
    factors were involved, any
  • one of which could have prevented this fatality.
  • If overrated lamps had not been used, the ballast
    would probably not have overheated and failed.
  • If the ground wire connection between the light
    fixture and the plug not been interrupted by the
    "cheater" adapter and the two-prong timer, the
    fixture would have safely shorted to ground
    tripping the circuit breaker when the equipment
    was plugged in before Dr. X touched it.
  • Had the standard outlet near the sink been Ground
    Fault Circuit Interrupter (GFCI) protected (as it
    should have been because it was near a sink), the
    GFCI would have tripped at the first flow of
    current through Dr. X immediately cutting off
    power to the fluorescent fixture and saving his
    life.
  • These electrical safety violations cost Dr. X his
    life.  If any one of them had been
  • corrected before the incident, Dr. X would still
    be researching plant growth.

18
Dont Let This Happen in Your Lab!
  • 1)Follow manufacturer's recommendations for use
    of  electrical
  • equipment.  Do not use electrical equipment for a
    task it is not designed
  • for.
  • 2) Generally, equipment used in research should
    have a 3 prong plug or
  • be double insulated. Equipment with neither of
    these features are less
  • safe but may meet electrical codes.  A 3 prong
    plug must always go into
  • a 3 prong outlet.  Do not use a "cheater" plug or
    pull out the 3rd prong.
  • 3) Do not use multiple cube taps in a standard
    outlet.  If you must plug
  • more than two pieces of low demand equipment into
    a standard outlet,
  • use a fused power strip that will trip if too
    much power is used.
  • 4) Make sure that any outlet near a sink or other
    water source is Ground
  • Fault Circuit Interrupter (GFCI) protected.  If
    you have a GFCI,
  • periodically test it by plugging something into
    it and pushing the "test
  • button.  The equipment should turn off and then
    turn it back on.

19
continued
  • 5) If you see a person being electrocuted, DO NOT
    TOUCH HIM!  The
  • electricity can go though you too.  If possible,
    remove the power (pull
  • plug or trip circuit breaker), or use a
    non-conductive item (e.g. wooden
  • broom handle) to pry him away from the contact.
  • 6) Above all, do not disable any electrical
    safety feature expecting that
  • another safety feature will protect you.  In the
    incident described above,
  • if proper lamps were used, the ballast could
    still have been defective
  • from other causes.  Also, GFCIs can be
    defective.  That is why they
  • should be periodically tested.
  • 7)  Check that power cords are in good condition.
  • 8) Do not use extension cords as a substitute for
    permanent wiring.

20
Electrical Work
  • Electrical work is only to be performed by
    qualified individuals
  • Contact Facilities X4588 for ALL electrical work
  • Do not attempt to fix on your own
  • Attempting to repair equipment
  • yourself may create a hazard

13
21
Conclusion
  • Know and follow safe work rules and practices
  • NO EXTENSION CORDS AS PERMANENT WIRING
  • POWER STRIPS ARE FOR ELECTRONICS ONLY
  • Report all unsafe conditions to Facilities X4588
    or EHS X4078
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