by Francis Jock

Created on: April 21, 2009   Last Updated: October 27, 2009

Are you facing the task of repairing an electrical switch or outlet in your home? Perhaps you are upgrading your home's outlets or lighting in the family room. On a larger scale, you may be thinking about installing a structured wiring system that needs more outlets than are available. Whatever the reason is for delving into the mysterious world of home electrical repair, you should begin with a solid understanding of the three wires that make everything work.

Three wires are all that are needed to operate appliances that use 120-volts AC, and one of them is a safety ground wire. In the most basic of terms, the other two wires divide the task of bringing electricity from the outlet to the appliance and then returning it from the appliance to the outlet. In other words, electricity flows into your home from the electrical grid, is partially used, or consumed there by all the appliances, TVs, computers, water heaters, lights, and every other gadget and the remainder is returned to the grid.

Shortly after electricity became the standard for household lighting; it became obvious that wiring had to be standardized in order to prevent mishaps, electrocution and fires. As a result, electrical wires are color-coded so the installer and the repair person will not mistake which wire is delivering the electricity and which is returning it. The delivering wire is the hot wire and is wrapped in a coat of black plastic. The returning wire is color coded white.

With the exception of the ground wire, the black and white wires make up the entire wiring system in most homes. The ground wire is an accompanying solid copper wire that connects each outlet and electrical box together to form a single continuous connection to ground. Electrically speaking, "ground" means that everything is connected to the earth by an 8-foot rod located adjacent to the utility meter.

The principle behind having a ground wire is that in the event that a spark should jump across a loose connection somewhere, it will be channeled to ground instead of building up a charge and arcing into the woodwork, or some other nearby device. Like water, electricity will always seek the path of least resistance, and the safety, or ground wire conveniently escorts any errant electricity to earth where it can do no harm.

When installing a new or replacement outlet, light switch, or lighting fixture, it is important to observe which wire goes where. On an outlet, there are two screws on either side. On one side, the

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