Power to the people! Fixing electrical things around your home sometimes means going to the source: the electrical power source. That's the electrical service panel where utility wires deliver electricity for distribution to the many circuits in your home. If you've checked the electrical device and the electrical receptacle, but haven't found the problem yet, maybe it's in the service panel, sometimes known as the main. Let's look.

How Does It Work?

The electrical service panel receives power from the utility company and distributes it to your home through safety circuit breakers.

The electrical service panel is the main panel or cabinet through which electricity is brought into the building and then distributed to various branch circuits. Power from the utility company (or your solar power system!) enters the panel through three large wires--two hot and one neutral. The main neutral wire connects to a neutral bus or common bar, and the two hot mains connect to the main power shutoff, either a large circuit breaker or a pull-out fuse.

Each of the two bars carries 120 volts. All circuit breakers or fuses in the service panel are connected to one or both of these bars. Fuses and breakers rated at 120 volts are attached to a single hot bar; 240-volt breakers or fuses are attached to both hot bars.

Each 120-volt circuit has a black or color wire connected to a circuit breaker or fuse; the white wire is connected to the neutral bus bar. Ground wires also lead to a neutral bar. Power runs through each fuse or breaker and then out of the panel via a hot wire to whatever receptacles, lights, or appliances are on the circuit. White neutral wires bring power back to a neutral bus bar in the service panel, completing the loop, also known as an electrical circuit.

What Can Go Wrong?

Electrical service panels have components inside them that are designed to fail: fuses or circuit breakers. They form the first line of defense for your home, protecting you and your family from electrical fire and shock. An overloaded circuit blows the circuit breaker or fuse--the weakest link--in the circuit. It's fixable or replaceable.

Caution!

Never touch the bus bar inside an electrical service panel unless the main breaker has been turned off or the main fuse removed.