Basic Electrical Safety

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Basic Electrical Safety

• By Greg Bock
• PLU Electrician

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Why Bother?

• In 1997, over 12,000 people went to hospital
  emergency rooms to be treated for electrical
  shocks and burns.
• Hundreds of workers die every year from
  electrical shock.
• The amount of current to power a 5-watt lightbulb
  is enough to kill three people.
• One of your co-workers was injured last year by
  electricity.

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Voltage, Current, Resistance

• Voltage is the pressure or force that carries the
  current.
• Current (amperage) is the amount of electricity
  that flows.
• Resistance slows down the flow of electricity.

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Current Vs. Resistance

• Metals are good conductors of current having very
  low resistance
• Rubber, ceramics, and wood are poor conductors of
  current with very high resistance.
• Materials with high resistance are often called
  insulators.
• The human body can be a very good conductor or a
  very poor conductor.

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Factors Affecting the Conductivity of the Human
Body

• Condition of the skin Is it wet, dry, greasy?
• Health of Individual
• Duration of Contact with Electricity
• Part of the Body contacted

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See Dos Donts Handout
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More Dos Donts

• Keep electrical equipment away from water sources
• Use a C-rated fire extinguisher on electrical
  fires and shut off power source
• Remove frayed or damaged equipment and cords from
  service
• Remove plugs by pulling the plug not the cord.

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See Extension Cord Handout
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Grounding Electrical Equipment

• Grounding functions to conduct current leaks to
  the earth or ground.
• A grounded cord is a 3-wire plug and requires a
  3-way receptacle.
• Double-insulated equipment does not require
  grounding.

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Electrical Shock Injury

• Amps Milliamps Injury
• 1 1000 Severe burns
• 0.1 100 Irregular heart beat
• (requires medical defibrillation)
• 0.01 10 Cannot release grip
• 0.001 1 Threshold of sensation

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See Electrical Shock Handout
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Summary

• Even low voltage electricity can cause injury.
• Your body can be a good conductor of electricity,
  especially when wet.
• Follow the Ground Rules of electricity.
• Do not use defective equipment.

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Electrical Safety

• Quiz