Why is it so important to work safely with or near electricity?
The electrical current in regular businesses and homes has enough power to cause death by electrocution. Even changing a light bulb without unplugging the lamp can be hazardous because coming in contact with the "hot" or live part of the socket could kill a person.
What kinds of injuries result from electrical currents?
There are four main types of injuries: electrocution (fatal), electric shock, burns, and falls. These injuries can happen in various ways:
direct contact with the electrical energy.
when the electricity arcs (jumps) through a gas (such as air) to a person who is grounded (that would provide an alternative route to the ground for the electricity).
thermal burns including flash burns from heat generated by an electric arc, and flame burns from materials that catch on fire from heating or ignition by electrical currents. High voltage contact burns can burn internal tissues while leaving only very small injuries on the outside of the skin.
muscle contractions, or a startle reaction, can cause a person to fall from a ladder, scaffold or aerial bucket. The fall can cause serious injuries.
What are some general safety tips for working with or near electricity?
Inspect tools, power cords, and electrical fittings for damage or wear prior to each use. Repair or replace damaged equipment immediately.
Always tape cords to walls or floors when necessary. Nails and staples can damage cords causing fire and shock hazards.
Use 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 may be a sign that unsafe wiring conditions exists. Unplug any cords to these outlets and do not use until a qualified electrician has checked the wiring.
Always use ladders made of wood or other non-conductive materials 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.
Make sure that exposed receptacle boxes are made of non-conductive materials.
Know where the breakers and boxes 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 power tools with the guards removed.
Do not block access to circuit breakers or fuse boxes.
Do not touch a person or electrical apparatus in the event of an electrical accident. Always disconnect the current first.
What are some tips for working with power tools?
Switch tools OFF before connecting them to a power supply.
Disconnect power supply before making adjustments.
Ensure tools are properly grounded or double-insulated. The grounded tool must have an approved 3-wire cord with a 3-prong plug. This plug should be plugged in a properly grounded 3-pole outlet.
Test all tools for effective grounding with a continuity tester or a ground fault circuit interrupter (GFCI) before use.
Do not bypass the switch and operate the tools by connecting and disconnecting the power cord.
Do not use electrical tools in wet conditions or damp locations unless tool is connected to a GFCI.
Do not clean tools with flammable or toxic solvents.
Do not operate tools in an area containing explosive vapours or gases.
What are some tips for working with power cords?
Keep power cords clear of tools during use.
Suspend power cords over aisles or work areas to eliminate stumbling or tripping hazards.
Replace open front plugs with dead front plugs. Dead front plugs are sealed and present less danger of shock or short circuit.
Do not use light duty power cords.
Do not carry electrical tools by the power cord.
Do not tie power cords in tight knots. Knots can cause short circuits and shocks. Loop the cords or use a twist lock plug.
What is a Ground Fault Circuit Interrupter (GFCI)?
A Ground Fault Circuit Interrupter (GFCI) works by detecting any loss of electrical current in a circuit. When a loss is detected, the GFCI turns the electricity off before severe injuries or electrocution can occur. A painful shock may occur during the time that it takes for the GFCI to cut off the electricity so it is important to use the GFCI as an extra protective measure rather than a replacement for safe work practices.
GFCI wall outlets can be installed in place of standard outlets to protect against electrocution for just that outlet, or a series of outlets in the same branch. A GFCI Circuit Breaker can be installed on some circuit breaker electrical panels to protect an entire branch circuit. Plug-in GFCIs can be plugged into wall outlets where appliances will be used.
When and how do I test the Ground Fault Circuit Interupter (GFCI)?
Test the GFCI monthly. First plug a "night light" or lamp into the GFCI-protected wall outlet (the light should be turned on), then press the "TEST" button on the GFCI. If the GFCI is working properly, the light should go out. If not, have the GFCI repaired or replaced. Reset the GFCI to restore power.
If the "RESET" button pops out but the light does not go out, the GFCI has been improperly wired and does not offer shock protection at that wall outlet. Contact a qualified electrician to correct any wiring errors.
What is a sample checklist for basic electrical safety?
Inspect Cords and Plugs
Check power cords and plugs daily. Discard if worn or damaged. Have any cord that feels more than comfortably warm checked by an electrician.
Eliminate Octopus Connections
Do not plug several power cords into one outlet.
Pull the plug, not the cord.
Do not disconnect power supply by pulling or jerking the cord from the outlet. Pulling the cord causes wear and may cause a shock.
Never Break OFF the Third Prong on a Plug
Replace broken 3-prong plugs and make sure the third prong is properly grounded.
Never Use Extension Cords as Permanent Wiring
Use extension cords only to temporarily supply power to an area that does not have a power outlet.
Keep power cords away from heat, water and oil. They can damage the insulation and cause a shock.
Do not allow vehicles to pass over unprotected power cords. Cords should be put in conduit or protected by placing planks alongside them.
How Electrically-Savvy Are You? What you don't know about electricity can be shocking! In addition to safety issues, a basic understanding of electricity can help you select the best electrical devices for your home and reduce your energy bill as well. The Leviton Institute helps you test your knowledge with the following true/false quiz on electricity.
1. Dimmers simply absorb energy from light bulbs and don’t save you any money. 2. Dimmers cannot be used to control ceiling fans. 3. GFCIs offer the same protection that circuit breakers do. 4. A 1200-Watt appliance draws 10 Amps of electrical current. 5. Only a licensed electrician can test a GFCI. 6. 12-gauge wire is rated to carry more electrical current than 14-gauge wire. 7. If a plug keeps falling out of a receptacle, use pliers to spread the plug blades farther apart. 8. Surges can enter your electronic equipment through phone and cable connections.
Answers 1. False. Dimmers don't absorb power. They control the amount of time a bulb is on and off 120 times a second, but your eye can't see this. A dim setting limits the time the bulb is on. A bulb dimmed to 50% uses approximately 25% less power and lasts approximately 20 times longer, saving both on lighting energy and bulb replacement costs. 2. True. Dimmers can damage fan motors. Only fan speed control units can be used with ceiling fans. They are usually available with the same styling and features as dimmers but are safe for fan motors. 3. False. Circuit breakers are designed to trip when a severe short causes high levels of electrical current to flow through your wires. GFCIs provide protection from ground fault. This can occur when current leaking from a damaged appliance travels to ground through a person touching the appliance. Ground fault current can be lethal, but is typically not high enough to trip a breaker. A GFCI is designed to trip when it senses a relatively tiny amount of ground fault current. 4. True. Light bulbs and appliances are rated in Watts, while electrical wiring is rated in Amps. Divide the Watts by 120 (the household voltage) to arrive at the amperage rating. In this case, 1200 Watts divided by 120 Volts equals 10 Amps. 5. False. Using a simple procedure you should test your GFCIs monthly. Plug a lamp into the GFCI and turn it on. Press the Test button—the GFCI should trip causing the light to go off. Press the Reset button on the GFCI and the lamp should go on again. This confirms that the GFCI is working properly. If the GFCI does not trip (shut off the light) when you press the Test button, there is an electrical problem and you should contact a licensed electrician. 6. True. The larger the diameter of wire, the more electrical current it can carry. What is sometimes confusing is that the larger the diameter, the smaller the wire gauge. For example, 14-gauge wire is rated for small electrical tools and appliances, but larger power tools require 12-gauge wire. 7. False. When a receptacle no longer holds a plug firmly in place, the half-inserted, live plug is a serious shock hazard, especially for children. When a receptacle is old or worn out by excessive use, its contacts no longer properly grip a plug. Any receptacle in this condition must be replaced. 8. True. Surges that can damage your PC, television, video recorder and answering machine can enter through phone, data line and cable connections. Use surge protective power strips that not only provide the maximum amount of powerline protection, but also offer protection for phone, data and cable lines. These multi-purpose surge strips are available in home centers, electronic stores and a variety of retail outlets.