Square D Interlock

This is a 3D printed version of the Square D Interlock. It allows you to safely use a generator to power your home during utility power outages restricting the power supplied to the circuit panel to a single source -- Utility Power OR Generator Power.

This interlock is designed for a Square D breaker panel but could be modified to work on most circuit breaker panels. The concept is simple: The main breaker must be switched OFF so the Auxiliary breaker that is connected to the Backup Power (generator) can be switched ON. This interlock prevents more than one of these sources to be ON, or powering the circuit panel, at any time.