The Main Service Panel
The main service panel performs three basic functions. It distributes power to all the electrical circuits in the home, it contains devices which protect those individual circuits from overload and it provides a master switch which is used to manually cut all power in the home. The main panel has three major sections which each perform a specific function: the main breaker, the hot bus and the neutral/grounding bus.
All the electricity that enters the home goes through the main breaker located at the top of the electrical panel. It enables homeowners to cut all power to the home in case of emergency and also protects the house from external electrical overloads.
Power flows through the main breaker to the hot bus. The hot bus is the two copper or aluminum strips which run down the center of the panel. Each strip has tabs for inserting circuit breakers. Power travels from the bus to the circuit breakers. Circuit breakers function the same as the main breaker but on an individual circuit only.
After power travels through the circuit breaker to the appliance or device which needs it, it returns to the service panel via the neutral/grounding bus. The neutral bus is the two aluminum strips with many screws located on the outer edges of the main panel. The screws are for attaching the neutral and ground circuit wires to the bus. This bus connects to the neutral cable from the utility meter.