Every home has a circuit panel, most of which contain a set of switches that can be flipped to turn power on and off to different areas of the house. What many people don’t realize is that most circuit breaker boxes control several different types of circuits. Since every area of your house has different electrical needs, each area has to be specially wired, and there are different concerns having to do with different areas.


What all circuits have in common, however, is that they have both hot and neutral wires. The hot wire is usually black or red and leads out to the outlets and electrical fixtures in the area controlled by the circuit, while the neutral wire is usually white and exists mainly to complete the circuit.

Types of circuits

Most circuits in private homes carry 120 volts, although you will occasionally see 240-volt circuits. When a circuit draws too many amps (i.e., the demand from the appliances and fixtures plugged in to the circuit is too high), the breaker will trip or a fuse will blow. To prevent unsafe conditions, home circuit systems are designed to automatically shut off when this happens.

A typical 120-volt circuit can serve a few outlets with normal power demand. However, some homes have specialized circuits devoted specifically to high-power items such as dishwashers or refrigerators. When this happens, many circuits and breakers automatically shut down.

Grounding and polarization

Because short circuits can cause shocks, circuits need to be grounded so that any excess electricity will be neutralized. That’s why most circuits have a grounding wire that gets attached to a neutral bar within the service panel. The bar is connected to the earth so that any electricity it conducts gets immediately grounded. Without this, the electricity might find its way into places where it could pose a danger.

Polarization is the process of ensuring that the electricity flows in the direction that it’s supposed to. In many of your plug-in devices you may notice that one of the prongs in the plug is wider than the other. This ensures that the electricity flows in the proper direction into the device. In items that have two prongs of the same size, it doesn’t matter which direction the electricity flows in. Polarization essentially acts as a cut-off, ensuring that devices don’t draw power even when they’re not in use.