Many home improvement projects involve electrical wiring. These tips can help make the job safer.
Ready to install that new ceiling fan or light fixture? Home electrical projects can be fun and rewarding…and safe if you’ll just remember a few concepts. Electric power comes into our homes (in the U.S. anyway) on three wires. We’ll call them Hot A, Hot B and Neutral or Common. Voltage is a measure of how much power an electric circuit can deliver and it is always measured between two wires. High powered equipment like clothes dryers use 220 Volt electricity while TV’s and stereos run on 110 Volts. If you measure the voltage between the Hot A and Hot B wires, you would see 220 Volts and if you measured between Hot A and Neutral or between Hot B and Neutral, you would see 110 Volts.
The electric wires that come into our homes are connected into the fuse or circuit breaker panel. Circuit breakers or fuses are actually special types of switches that can turn themselves off automatically if certain dangerous conditions are present. We’ll talk more about them later but here’s what’s important for now. You cannot turn off the electricity coming into your home. That means that inside the circuit breaker panel the electricity is always on. The first safety rule is this. Don’t try to work inside the circuit breaker panel; leave this to the experts.
The second safety rule is: Turn off the power AT THE CIRCUIT BREAKER. I said before that circuit breakers are switches. You can turn them off manually by opening the door to the circuit breaker panel, locating the right breaker and flipping the switch.
The next rule is: Verify that the power is off. Don’t trust the labels inside the breaker panel. They are seldom accurate. Turn on the light or whatever you’re going to work on and flip breakers until it goes off. Your local hardware or builders supply store has an instrument (it usually looks like a pencil) that when turned on and held close to a wire will beep and flash if there is electricity in the wire. These instruments are inexpensive and invaluable. Often more than one circuit breaker will be connected to an outlet box. This instrument will warn you if all of the electricity isn’t off.
In normal house wiring (110 Volt), you will see two and possibly three wires. The black wire is normally connected to either the Hot A or Hot B wire while the white wire is connected to Neutral. However, there is no guarantee that this will always be true. The green wire, if it is present, is the safety ground wire. Safety rules for wiring state that a switch should generally (there are some exceptions) be connected to the Hot (black) wire. Outlet receptacles have chrome colored screws and brass colored screws. The black wire should be connected to the brass colored screws and the white wire to the chrome.
Wires are usually connected by twisting together the bare ends and screwing a wire nut (also called a toothpaste cap) onto them. These special connectors can be purchased at hardware or builders supply stores in sizes to fit whatever wire you’re using. Do not just twist the wires together and cover them with tape. This creates a severe fire hazard.
After the job is finished, turn the circuit breaker back on. If it pops back to the middle and will not stay on, there is a problem somewhere in the wiring. Circuit breakers are designed to turn themselves off if they detect an electrical problem. Never wire, tie or otherwise force a circuit breaker to stay in the ON position. This can cause fire and destruction of electrical equipment.
This is by no means a complete list of possible electrical safety hazards but minding these rules will give you a safe basis for your at home electrical work.