Circuits

Every time you flip on a light, you're seeing a circuit at work. In scientific terms, a circuit is the complete path that electric current takes, as it travels from a source, along the wires, to the device it's operating, and back to the source. That's how electricity moves through your house, to accomplish its various tasks: illuminating a light, running the refrigerator, or supplying power when you plug in a blow dryer. Circuits begin at the main service panel, and are protected by a circuit breaker, which trips in the event of a short or overload. Each circuit can support a limited number of devices, depending on the size of wire used, and what it needs to power. Typically, you'll have several outlets on the same 120-volt circuit, whereas heavy-duty appliances like a water heater and kitchen stove each need their own 240-volt circuit. Electrical codes now require that any circuit of at least 120 volts also have a grounding system, to guard against shock. For more information about circuits, and how they work, consult a local electrician.