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 screws are brass, while on the other side they appear a lighter white. The conventional rule-of-thumb for making a wiring connection to an outlet is "White-to-White" and Black-to-Brass". That only leaves the copper ground wire which is attached to the ground lug at the bottom of the outlet.
There are only a few tools required to make everyday household electrical repairs. A pair of needle nosed pliers, a roll of electrician's plastic tape, pair of lineman's pliers, and a multipurpose wire stripper and crimper make up the basic electrician's tool box. Two other necessary pieces of equipment are a continuity checker and a voltage tester.
A voltage tester can be a simple device that lights up when plugged into or connected to an outlet or a wire. More sophisticated devices include Volt-Ohm-Meters, Multimeters, and inductive probes that chirp whenever positioned near a wire that is hot, or live with electricity. These devices serve as a warning that electricity is present and should be turned off before going any further with your work.
When installing ceiling fans, Ground Fault Interrupters, or two-way switches, it is important to follow the manufacturer's directions supplied with the device. You are likely to encounter red or blue wires with the device and these have to be connected properly in order for the device to work as designed.
Equipped with this information, you should now have a good understanding of household positive, negative and ground wires. If you are unsure about how to properly wire a device or make an electrical repair, you should consult with a licensed electrician. As a final safety precaution, never work in a wet, damp or confined space unless you are absolutely certain that every precaution and safety measure has been taken to turn off the electricity to the circuit being repaired.