How Electrical Supply Panels Work

The electrical supply panel in your home can almost be considered the brains of your home's electrical system. It is usually a big box with either fuses or circuits inside. It is often found in the basement or the garage of the home. Sometimes it can be found in a room, if the home does not have a basement or a garage. The electrical supply panel is responsible for distributing the electric current to the various circuits in the home. Here is how an electrical supply panel work.

How the Electricity Enters the House

The electricity enters the home from the street. Service wire either runs under the landscaping in underground wiring or it travels above the house in the wiring attached to the poles in front of the home. The service wire then connects to the wire coming into the home, which is ultimately connected to the electric supply panel through the main circuit breaker (also known as the main disconnect). (Note: The service wire and the rating on the panel must be similar in amperage. Therefore, you cannot supply 200 amps to a home if the outside service wire is only rated for 100 amps). Many homes today have a 150 amp or 200 amp service panel.

Hot Bus Bars

From the main circuit, you will see two service wires. They are hot (meaning 'electrically charged') and they carry 120 volts each. These wires will connect to the electrical bus bars in the electrical supply panel. The bus bars are what is responsible for supplying the power to the circuit breakers.

The Panel

Open the panel door and you will see many circuits. The circuits are usually lined in two rows. There are switched located on each of the circuits. There are two positions for each of the switches: on and off. When the circuit is located in the on position, the electricity passes through the circuit to the appliance.

Lighting and Powering Up

From the electrical supply panel, the electricity will travel to the light, or the appliance and make it work. The electricity moves along the black wiring from the service panel right into the electronic device.

Returning to the Electrical Supply Panel

Once the appliance or light is working, the electrical current will enter back into the electrical supply panel through the neutral circuit. The neutral bar, found in the electrical supply panel connects each of the neutral circuits.

The Circuit Breaker

The circuit breaker is actually a weak device, designed to trip when an electrical surge or overload occurs. It is designed to help prevent overloading of electrical current, a main cause for many house fires.

Grounding Out

For safety, each electric supply panel is connected to a grounding rod that is pounded into the earth. The neutral bar within the panel is attached to the ground rod. This is a safety feature and is often required in all homes. When you sell a home, the home inspector will likely look for the ground rod placement and utilization.