ELECTRICAL SAFETY AWARNESS TRAINING

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ELECTRICAL SAFETY AWARNESS TRAINING
Training Program
Updated 5/5/04
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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

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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.

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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

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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

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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

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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
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Damaged and Unapproved Devices
Not Permitted
Cord plug with ground prong missing
Damaged TVSS rated power strip
Adapter enables circuit overload
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Damaged and Unapproved Devices
Not Permitted
Lamp extension cord, also damaged
Power taps
Adapter to change 3-prong plug to 2-prong
eliminating ground
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Container Bonding and Grounding(Static
Electricity)
Bonding Cable
Grounding Cable
Grounding Bus
or Electrode
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• 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.

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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

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Electrical Safety Incidents

• The following is an example of
• Electrocution Due to Improper Use of Common
  Equipment

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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

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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