The generator interlock kit contains several parts, the most important being the interlock switch.
This device is installed in your electrical panel. When switched on, it prevents your portable generator and the main electrical grid from powering your electrical panel simultaneously.
This switch solves two potential problems:
1. Your expensive appliances and electronics are protected from an electrical surge when your main power is restored.
2. Electrical workers are better protected because electricity from your home is unable to back-feed on the powerlines.
Using an interlock kit also makes it easier for you to power what you want during an outage, including ceiling fans and other appliances that are hard-wired into your home.