Inside the panel, connections are made to the incoming wires.

These connections are then used to supply power to selected

portions of the home. There are three different combinations:

1) one hot, one neutral, and ground: 110V circuit.

2) two hots, no neutral, and ground: 220V circuit.

3) two hots, neutral, and ground: 220V circuit + neutral,

and/or two 110V circuits with a common neutral.