Basic Electrical Safety By Greg Bock PLU Electrician
Why Bother? b In 1997, over 12,000 people went to hospital emergency rooms to be treated for electrical shocks and burns. b Hundreds of workers die every year from electrical shock. b The amount of current to power a 5-watt lightbulb is enough to kill three people. b One of your co-workers was injured last year by electricity.
Voltage, Current, Resistance b Voltage is the pressure or force that carries the current. b Current (amperage) is the amount of electricity that flows. b Resistance slows down the flow of electricity.
Current Vs. Resistance b Metals are good conductors of current having very low resistance b Rubber, ceramics, and wood are poor conductors of current with very high resistance. b Materials with high resistance are often called insulators. b The human body can be a very good conductor or a very poor conductor.
Factors Affecting the Conductivity of the Human Body b Condition of the skin: Is it wet, dry, greasy? b Health of Individual b Duration of Contact with Electricity b Part of the Body contacted
See Do’s & Don’ts Handout
More Do’s & Don’ts b Keep electrical equipment away from water sources b Use a C-rated fire extinguisher on electrical fires and shut off power source b Remove frayed or damaged equipment and cords from service b Remove plugs by pulling the plug; not the cord.
See Extension Cord Handout
Grounding Electrical Equipment b Grounding functions to conduct current leaks to the earth or ground. b A grounded cord is a 3-wire plug and requires a 3-way receptacle. b Double-insulated equipment does not require grounding.
Electrical Shock Injury AmpsMilliampsInjury 11000Severe burns Irregular heart beat (requires medical defibrillation) Cannot release grip Threshold of sensation
See Electrical Shock Handout
Summary b Even low voltage electricity can cause injury. b Your body can be a good conductor of electricity, especially when wet. b Follow the Ground Rules of electricity. b Do not use defective equipment.
Electrical Safety Quiz