People often get nervous when it comes to electrical work, but you'd be surprised at just how easy wiring an outlet can be. While basic home wiring is a safe do-it-yourself project if done properly, if you don't know what you're doing, you could get injured. As with any job you undertake, safety is the number one priority. The mantra to a successful electrical repair or installation is Respect the Electricity!
There are many reasons why you may want to install a new outlet, but more often than not it's because the room does not have enough or there isn't one near enough. The level of difficulty for this project depends on where the outlet is going in relation to the existing ones. If you want to install an electrical outlet on a different wall from the existing ones, it can prove to be a little more difficult.
Step 1 - Choose Your Location
Pick where you want to install the electrical outlet and find the nearest existing outlet. Plug a lamp into it and go to the electrical panel to determine which breaker controls the circuit. Mark and turn off the breaker.
Step 2 - Test the Panel
You'll have to make sure the breaker can handle the additional load you're planning to put on it. Unscrew and remove the panel cover. Be very careful here, the panel is still electrified. Set your Volt-Ohm Meter to AMPS and probe the wire attached to the breaker. Depending on the type of meter, it may come with a clamp that clamps over the wire, or it may have a "U" shape that slides over the wire. Check the instructions for your meter.
Once you get the amperage, write it down and put the cover back on the panel. Use gloves to help avoid injury.
Step 3 - Calculate the Electrical Load
To determine if the breaker can handle the extra load, you'll need to know what the outlet will be used for. Most appliances have the amperage already labeled on them. If it is not in amps, such as a 60-watt lamp, you will need to convert using this formula AMPS=WATTS/VOLTS. The volts number will be what the voltage is in your house, usually 120 volts. So, the equation will be AMPS=60/120. The answer is 0.5 amps. Now add that number to the amperage reading from the breaker and make sure it doesn't exceed 80 percent of the listed breaker rating.
A 20 amp breaker shouldn't have more than 16 amps loaded on it. Ensure the breaker is off and double check the circuit with the voltage tester.
Step 4 - Measure and Mark
Use the stud finder to locate all the wall studs between the new location and the nearest existing outlet. Mark them lightly with a pencil. Remove the cover and outlet from where you will be getting your feed. Next, use a tape measure to measure how far up the wall from the floor the other outlets in the room are. Measure and mark the new location to match. Turn the old-work box around and place it against the wall where it will be going. Trace the box with the pencil.
Step 5 - Cut and Drill
Put the goggles and face mask on, and place a drop cloth down before you cut. Cut the drywall following the pencil lines with the drywall saw. Slide the old-work box in the opening to make sure it fits.
Find the previously marked studs and cut a square in the drywall so the stud is exposed. Take the drill with the hole bit and drill through every stud between the new outlet and the one that's going to feed it.
Step 6 - Run the New Wire
Take the wire fish and run it through the holes, from one end to the other. Use electrical tape to tape the romex wire to the wire fish and gently pull the wire fish back, bringing the romex wire with it.
Step 7 - Set the Wire in the New Box
Once you have the wire run from the new location to the feed outlet, cut the remaining wire off. Use the Romex stripper to make a cut in the plastic coating to expose the wires, about 12 inches worth. Slide the wires into the opening on the back of the old-work box. If you bought a plastic box, the connector is a pressure type; if it's a metal box, then you'll have to take a knockout out and tighten the connector down inside.
Either way, make sure the connector is holding the romex at the place where the plastic coating is still on, NOT on the exposed wires. Push the old-work box back into the wall and tighten down the "wing" screws with a screwdriver.
Step 8 - Wire Up the New Outlet
With the box in the wall, cut any excess wire off. You should keep about six inches of wire in the box. Strip away about 3/4-inch of the insulation on the wires with the wire strippers. Depending on the outlet you purchased, it may have side screws to hold the wire or it may have holes on the back to pressure-hold them. The most secure way is with the side screws.
The black wire gets connected to the copper, or the darker colored screw. The white wire gets connected to the silver, or the lighter colored screw. The ground gets connected to the green screw on the outlet. Once the wire is connected, wrap electrical tape around the outlet, covering the screws. Gently push the outlet back into the box and tighten the screws to hold it in place. Screw the cover on the outlet.
Step 9 - Tap into the Old Outlet
Make sure the power is off! Back at the feed outlet, follow the same method of stripping the romex and its wires and connecting it to the box. Next, cut about 12 inches of romex from the coil, not the wall wire. Strip all the plastic coating away so you have individual wires. Strip 3/4-inch of the insulation on one end of all three wires. Take the exposed end of the black wire and connect it to the black wire that feeds the new outlet and the black wire that was feeding the existing outlet. Twist them together and tighten a wire nut over them. This is called a "pigtail."
Follow that step with the white wires and the ground wires. Tape the wire nuts where the wires meet the nuts and carefully bend them back in the box. There should be a black, white, and ground wire hanging out of the box. Cut the wire back to about six inches and strip them as described before. Connect them to the outlet the same way as earlier. Don't forget to tape the outlet. Screw the outlet back onto the box and replace the cover.
Step 10 - Turn on the Power and Test it
Head back to the electrical panel and turn the breaker back on. Test both the new outlet and the feeding outlet with the voltage tester to make sure everything is wired correctly.
Once you check the electricity, and everything is OK, the only thing left to do is to clean up. Replace the cut drywall squares and repair them with the joint compound. Then touch up the paint as needed and enjoy the satisfaction knowing that you accomplished wiring an outlet yourself!