When power lines are down, residents can restore energy to their homes or other structures by using another power source such as a portable generator. If water has been present anywhere near electrical circuits and electrical equipment, turn off the power at the main breaker or fuse on the service panel. Do not turn the power back on until electrical equipment has been inspected by a qualified electrician.
If it is necessary to use a portable generator, manufacturer recommendations and specifications must be strictly followed. If there are any questions regarding the operation or installation of the portable generator, a qualified electrician should be immediately contacted to assist in installation and start-up activities. The generator should always be positioned outside the structure.
When using gasoline- and diesel-powered portable generators to supply power to a building, switch the main breaker or fuse on the service panel to the "off" position prior to starting the generator. This will prevent power lines from being inadvertently energized by back feed electrical energy from the generators, and help protect utility line workers or other repair workers or people in neighboring buildings from possible electrocution. If the generator is plugged into a household circuit without turning the main breaker to the “off” position or removing the main fuse, the electrical current could reverse, go back through the circuit to the outside power grid, and energize power lines or electrical systems in other buildings to at or near their original voltage without the knowledge of utility or other workers.
Effects of Back feed
The problem of back feed in electrical energy is a potential risk for electrical energy workers. Electrocutions are the fifth leading cause of all reported occupational deaths. Following the safety guidelines below can reduce this risk.
Other Generator Hazards
Generator use is also a major cause of carbon monoxide (CO) poisoning. Generators should only be used in well ventilated areas.