A 100 amp breaker box wiring diagram provides a detailed overview of the electrical wiring within the breaker box. It shows the locations of each wire, the type of wire used, and the size of the wire. The breaker box is the hub of your electrical system, distributing power throughout your home. Whether you're building a new home or upgrading your current electrical system, understanding how to wire a 100 amp. 100 amp breaker box wiring is one of the most common electrical projects in residential homes — whether you're adding a subpanel to a detached garage, upgrading an outdated system, or feeding a new living space.