A backup generator supplies electricity during a power outage, typically for brief periods. The electrical capacity of a backup generator is directly related to the cost, so buyers must carefully calculate their electric requirements when making their purchase decision. The operation of power generators involves significant safety considerations.
Overview
The fuel supply for a backup generator is usually gasoline, propane or natural gas. A backup generator connects directly to the house’s main power supply. A transfer switch on the generator detects a power loss and automatically turns the generator on. This allows the house to have electricity during the power outage with minimal interruption. The transfer switch also turns the generator off when it detects power from the house’s main power supply. Backup generators typically run regular self-tests automatically to ensure these power transfers occur smoothly.
Power
The power of a deck of generator must be greater than its maximum total load when the generator starts up. This generally requires you to add the running our of all the electrical appliances you wish to operate at the same time. You must also add the startup power of your largest appliance to this total, typically an air conditioner or furnace. The startup wattage should be listed on the appliance and is typically three to five times the running wattage of the appliance. You can also calculate an appliance’s power requirement by multiplying its amperage by its voltage.
Backup generators do not typically supply power for the entire house; rather, they usually just supply power for essential needs. A 20,000-watt generator will typically be needed to run an entire home and usually costs about $7,000. A 10,000-watt generator is adequate for a small home or job site, and typically costs about $5,500. Backup generators for emergency purposes only can be substantially smaller.
Safety
The biggest risk of operating a backup generator is that it produces carbon monoxide as an exhaust gas. Backup generators were responsible for 85 deaths by carbon monoxide in 2005, according to the Consumer Product Safety Commission. It is essential that the backup generator is outside when it is running, preferably at a distance of at least 10 feet. Gasoline engines produce much more carbon monoxide than those that run on propane or natural gas.
Electricity and fire hazards are also important safety considerations when operating a backup generator. You generally need to plug the electrical clients is directly into the generator using heavy-duty extension cords rated for exterior use. A single extension cord should also connect the generator to the transfer switch.
