Emergency Generator Safety
Keeping It Affordable and Safe
To cut costs when planning an emergency power supply for a home or business, consider providing sufficient capacity for only essential appliances, disconnecting the “frills” until normal service is restored.
More important than sizing is correct installation. Auxiliary power sources must be completely isolated from co-op lines attached to your meter to avoid backfeed into your co-op’s system. During an outage, line workers trying to restore power-or anyone who contacts a downed line-could be seriously injured or killed by backfeed from an improperly installed generator.
A special switch is used to transfer a building’s wiring from normal to a standby power source. The switch- called a double-throw device- is designed to prevent a generator’s feedback from passing through the co-op’s lines and transformers. The switch makes it impossible to connect the main power source to the generator. Its use is required by the National Electric Code when connecting an auxiliary power source to an existing system.
Remember, the switch and its wiring will carry all the load for the building it serves when connected to co-op lines during normal operation. These switches, like the generators they connect, are available in several configurations and power ratings. Choose one matched to your co-op service connection- 200 amp, 400 amp, three-phase, etc.- not one matched to the generator output.
In most areas, local codes and co-op policies require that auxiliary power connections be inspected and approved by a recognized electrical inspection agency before they can be used.
If you are considering installing an emergency back-up generator, contact your local co-op as well as generator equipment dealers. Together they can help you select a system that will safely provide temporary power when needed without creating additional problems or hazards.