Generators

Home generators are handy for backup electricity in case of an outage but must only be used in accordance with the manufacturer's guidelines. A backup generator may only be connected to your home's electrical system through an approved transfer panel and switch that has been installed by a qualified electrician. Never plug a generator into a wall outlet as serious injury can result when the current produced by the home generator is fed back into the electrical lines and transformed to a higher voltage. This can endanger the lives of utility employees working to restore the power.

• Using a Generator
• Other Resources

Purchasing a Generator

• When buying a generator, make sure you get one that is rated for the amount of power that you think you will need. Look at the labels on lighting, appliances and equipment you plan to connect to the generator to determine the amount of power that will be needed to operate the equipment.
• For lighting, the wattage of the light bulb indicates the power needed. Appliances and equipment usually have labels indicating power requirements on them. Choose a generator that produces more power than will be drawn by the combination of lighting, appliances and equipment you plan to connect to the generator including the initial surge when it is turned on. If your generator does not produce adequate power for all your needs, plan to stagger the operating times for your equipment.
• If you cannot determine the amount of power that will be needed, ask an electrician to determine that for you. If your equipment draws more power than the generator can produce, you may blow a fuse on the generator or damage the connected equipment. You can also find charts online by searching 'generator size calculator."
• If you plan to connect your generator directly to your electrical system, a qualified electrician must install it. The electrician must apply for a wiring permit and have the generator inspected by an electrical utility wiring inspector before it is used.

Using a Generator

• The primary hazards to avoid when using a generator are carbon monoxide (CO) poisoning from the toxic engine exhaust, electric shock or electrocution, and fire. Follow the manufacturer's instructions supplied with the generator.
• Ensure that the generator operates outdoors in well-ventilated conditions, well away from doors or windows, and never in your garage, to prevent exhaust gases from entering the house. Under no circumstances should portable generators be used indoors, including inside a garage, carport, basement, crawlspace or other enclosed or partially enclosed area, even with ventilation. Opening doors and windows or using fans will not prevent CO buildup in the home (see carbon monoxide poisoning). Use portable generators outdoors in well ventilated areas at least 20 feet (7 metres) from all doors, windows and vent openings. Measure 20-foot (7 metre) distance from the generator to the building.
• To avoid electrocution, keep the generator dry and do not use it in rain or wet conditions. To protect the generator from moisture, operate it on a dry surface under an open canopy, such as under a tarp held up on poles. Dry your hands if wet before touching the generator.
• Be sure to turn the generator off and let it cool down before refueling. Gasoline spilled on hot engine parts could ignite.
• Store fuel for the generator in an approved safety can. Use the type of fuel recommended in the instructions or on the label on the generator. Local laws may restrict the amount of fuel you may store or the storage location. Ask your local fire department for additional information about local regulations.
• Store the fuel outside of living areas in a locked shed or another protected area. Do not store it near a fuel-burning appliance, such as a natural gas water heater in a garage. If the fuel is spilled or the container is not sealed properly, vapours from the fuel can travel along the ground and can be ignited by the appliance's pilot light or by arcs from electric switches in the appliance.
• Plug appliances directly into the generator or use a heavy-duty, outdoor-rated CSA-approved extension cord that is rated (in watts or amps) at least equal to the sum of the connected appliance loads. Check that the entire cord is free of cuts or tears and that the plug has all three prongs, especially a grounding pin. Never try to power the house wiring by plugging the generator into a wall outlet, a practice known as “backfeeding.” This is an extremely dangerous practice that presents an electrocution risk to utility workers and neighbours served by the same utility transformer. It also bypasses some of the built-in household protection devices.
• Generators do not need to run constantly. For example, fridges and freezers can be on the generator every 3-6 hours to keep things cold.

Other Resources

NFPA Generator Safety (PDF)

Source: Environmental Health - Emergencies and Extreme Weather Events - Preventing Injuries