An introductory guide to home electricity

There's plenty of electrical jobs the average homeowner can do on their own, as long as they stay safe. This guide walks you through the basics of home electricity so you can do home repairs safely and effectively.

Your first step to understanding electricity in your home is knowing how it comes in and where it goes. Here's the typical path electricity goes through homes:

• Electricity enters your home through an electric meter. From there it goes to a main service panel.
• The main service panel has circuit breakers or fuses and distributes the power to the house's various circuits.
• A circuit typically covers one part of the house and contains a number of outlets, such as receptacles and light fixtures.
• Each circuit is a closed loop. Electrical current leaves the service panel on the hot (usually black) wire and returns through the neutral (white) wire.
• When you flip a switch, the circuit is interrupted, cutting the flow of electricity to the fixture.
• Electrical systems also have a ground (bare or green) wire to carry excess current harmlessly to the ground in case of a short circuit.

Electricity flows through wires much like water flows through pipes and is measured by volts amps and watts.

• Volts measures the electrical pressure that causes current to flow. This pressure is set by your electrical utility company and is 120 volts for most circuits, but larger appliances may require 240 volts.
• Amps, or amperes, is the rate at which the electricity flows .
• Watts is the amount of power a lamp or appliance actually draws, which takes both volts and amps into account. For example, a light bulb that draws a 1⁄2 amp through a 120 volt circuit uses 60 watts (1⁄2 x 120).

• Think of ground wires as your home's electrical safety net. They don't normally carry a current, but they provide a safe path for electricity to disperse during a short circuit or emergency.
• The electrical code now requires that all new and upgraded wiring be fully grounded. But in older homes, the receptacles and lighting fixtures are often not grounded.
• Ungrounded receptacles have only two slots while grounded ones have a third round hole. This allows them to accept the three-prong plugs found on many heavy-duty appliances that need to be grounded to be used safely.
• Be aware that not all receptacles may have that third round hole without really being grounded. People often replace ungrounded receptacles with grounded ones, and leave the grounding unconnected, which is dangerous.
• To tell if a receptacle is grounded, use an inexpensive receptacle analyzer. If you spot a problem, turn off the power and have the receptacle's connections serviced.
• If you suspect that your entire electrical system is not properly grounded, have it inspected by an electrician.

Whether it's replacing a broken switch or installing a new light fixture, many simple electrical jobs can be easily done by the average homeowner. But to do it safely, it's important for you to know what precautions to take, how to do the job properly and understand how electricity works in your home. Remember: when in doubt, always call a professional.