Basic Electrical SafetyTalk

WHAT’S AT STAKE?

STATIC AND DYNAMIC ELECTRICITY

All electrical systems have the potential to cause harm. Electricity can be either “static” or “dynamic.” Dynamic Electricity is the uniform motion of electrons through a conductor (this is known as electric current). Conductors are materials that allow the movement of electricity through it. Most metals are conductors. The human body is also a conductor.

Static Electricity is accumulation of charge on surfaces as a result of contact and friction with another surface. This contact/friction causes an accumulation of electrons on one surface, and a deficiency of electrons on the other surface.

Path or Loop

Electric current cannot exist without an unbroken path to and from the conductor. Electricity will form a “path” or “loop”. When you plug in a device (e.g., a power tool), the electricity takes the easiest path from the plug-in, to the tool, and back to the power source. This is action is also known as creating or completing an electrical circuit.

Installation / Maintenance of Electrical Systems

Almost every building has an electrical power, communications, lighting, and control system that is installed during construction and maintained after that. These systems power the lights, appliances, and equipment that make people’s lives and jobs easier and more comfortable.

Installing electrical systems in newly constructed buildings is often less complicated than maintaining equipment in existing buildings because electrical wiring is more easily accessible during construction. Maintaining equipment and systems involves identifying problems and repairing broken equipment that is sometimes difficult to reach. Maintenance work may include fixing or replacing parts, light fixtures, control systems, motors, and other types of electrical equipment.

WHAT’S THE DANGER?

FOUR TYPES OF INJURIES

  1. Electrocution (fatal)
  2. Electric Shock
  3. Burns
  4. Falls

These injuries occur as follows:

  • Direct contact with exposed energized conductors or circuit parts. When electrical current travels through our bodies, it can interfere with the normal electrical signals between the brain and our muscles (e.g., heart may stop beating properly, breathing may stop, or muscles may spasm).
  • When the electricity arcs (jumps, or “arcs”) from an exposed energized conductor or circuit part (e.g., overhead power lines) through a gas (such as air) to a person who is grounded (that would provide an alternative route to the ground for the electrical current).
  • Thermal burns including burns from heat generated by an electric arc, and flame burns from materials that catch on fire from heating or ignition by electrical currents or an electric arc flash. Contact burns from being shocked can burn internal tissues while leaving only very small injuries on the outside of the skin.
  • Thermal burns from the heat radiated from an electric arc flash. Ultraviolet (UV) and infrared (IR) light emitted from the arc flash can also cause damage to the eyes.
  • An arc blast can include a potential pressure wave released from an arc flash. This wave can cause physical injuries, collapse your lungs, or create noise that can damage hearing.
  • Muscle contractions, or a startle reaction, can cause a person to fall from a ladder, scaffold or aerial bucket.

HOW TO PROTECT YOURSELF

ELECTRICAL SAFETY BASICS

  • Don’t work with exposed conductors carrying 50 volts or more.
  • Make sure electrical equipment is properly connected, grounded and in good working order.
  • Extension cords may not be used as permanent wiring and should be removed after temporary use for an activity or event.
  • Surge suppressors with built-in circuit breakers may be used long-term and are available with three, six and 15 foot-long cords.
  • High amperage equipment such as space heaters, portable air conditioners and other equipment must be plugged directly into permanent wall receptacles.
  • Do not access, use or alter any building’s electrical service, including circuit breaker panels, unless you are specifically qualified and authorized to do so.
  • Wet environments can increase the risk of an electrical shock.

Housekeeping and Maintenance

  • Maintain at least 30 inches of clearance in front of electrical panels to ensure a safe environment for facilities workers.
  • Make sure that all junction boxes are covered.

Avoid activities that requires training

  • Working with exposed conductors carrying 50 volts or more
  • Making repairs or alterations to any electrical equipment
  • Opening up the case, or removing barrier guards, of any equipment that utilizes electricity
  • Using any tools or a meter to measure for the presence of electricity
  • Resetting a tripped circuit breaker, or replace a blown fuse

General Safety Tips For Working With Or Near Electricity

  • Inspect portable cord-and-plug connected equipment, extension cords, power bars, and electrical fittings for damage or wear before each use. Repair or replace damaged equipment immediately.
  • Always tape extension cords to walls or floors when necessary. Do not use nails and staples because they can damage extension cords and cause fire and shocks.
  • Use extension cords or equipment that is rated for the level of amperage or wattage that you are using.
  • Always use the correct size fuse. Replacing a fuse with one of a larger size can cause excessive currents in the wiring and possibly start a fire.
  • Be aware that unusually warm or hot outlets or cords may be a sign that unsafe wiring conditions exists. Unplug any cords or extension cords from these outlets and do not use until a qualified electrician has checked the wiring.
  • Always use ladders made with non-conductive side rails (e.g., fibreglass) when working with or near electricity or power lines.
  • Place halogen lights away from combustible materials such as cloths or curtains. Halogen lamps can become very hot and may be a fire hazard.
  • Risk of electric shock is greater in areas that are wet or damp. Install Ground Fault Circuit Interrupters (GFCIs) as they will interrupt the electrical circuit before a current sufficient to cause death or serious injury occurs.
  • Use a portable in-line Ground Fault Circuit Interrupter (GFCI) if you are not certain that the receptacle you are plugging your extension cord into is GFCI protected.
  • Make sure that exposed receptacle boxes are made of non-conductive materials.
  • Know where the panel and circuit breakers are located in case of an emergency.
  • Label all circuit breakers and fuse boxes clearly. Each switch should be positively identified as to which outlet or appliance it is for.
  • Do not use outlets or cords that have exposed wiring.
  • Do not use portable cord-and-plug connected power tools if the guards are removed.
  • Do not block access to panels and circuit breakers or fuse boxes.
  • Do not touch a person or electrical apparatus in the event of an electrical incident. Always disconnect the power source first.

FINAL WORD

Electrical repairs must be carried out only by persons who are qualified and authorized to do so. Makeshift repairs of electrical equipment have resulted in many deaths in the workplace. Remember, you are in danger of electrocution if testing and repairs are done incorrectly.