Generator Transfer Switch Safety Guide

A transfer switch lets a generator safely power a home's existing wiring and circuit breakers, instead of running extension cords to individual appliances room by room.

Without a transfer switch, backfeeding a home's panel by plugging a generator into a wall outlet is dangerous and illegal in most jurisdictions — it can send live current back down the line toward utility workers repairing the outage, and risks fire from an overloaded circuit.

Manual transfer switches are less expensive and require flipping breakers by hand; automatic transfer switches (usually paired with standby generators) switch over within seconds with no manual action. Either should be installed by a licensed electrician.