Faulty electrical wiring is the root cause of approximately 67,800 residential fires in the United States every year. These fires cause $868 million in property damages and claim the lives of 485 adults and children every single year. Faulty electrical wiring causes twice as many residential fires as those caused by residential electrical appliances. Over 33 percent of the fires caused by faulty wiring have been traced to faulty electrical receptacles.
Receptacles simply wear out over time, especially those that receive a lot of use. With the constant insertion and extraction of plugs the receptacles internal contacts lose their tension and their ability to grasp the blades of the plug. Loose contact makes for very high resistant connections, this causes arcing, and heat build up which can ignite the surrounding combustible wall materials, curtains, etc. Replacing these defective receptacles is an easy task for the average DIY electrician.
With this article, we will continue to build our DIY electrician’s tool kit by adding two new pieces of test equipment, a non-contact voltage checker and a circuit tracer. Both are relatively inexpensive and available at most home centers as well as on line.
Non-contact voltage checkers like the Greenlee non-contact voltage detector model GT-11 sells for around $15.00 at most home centers. Most testers like your digital Multimeter or even a neon test lamp depends on a good ground or return circuit to work and if one isn’t present, there could still be voltage present but the meter would indicate no voltage present and give you a false feeling of safety. The non-contact voltage detector will indicate the presence of voltage whether there is a complete return path or not. In addition, with the non-contact detector you don’t have touch probes to a live terminal to get a reading. The non-contact detector works by detecting electromagnetic field surrounding every current carrying conductor much like a radio receiver detects radio waves.
The circuit tracer is a two-piece unit similar to the tone generator and receiver probe used by telephone installers to trace out phone wiring in your home. Units like the Gardner Bender Circuit Tracker- Circuit Breaker Finder GET-1200 Model: GET-1200 can be purchased at most home centers for under $40.00. What this tool does is determine which circuit breaker you need to turn off to kill the circuit that you want to work on. The transmitter plugs into the live receptacle and you run the receiver up and down the two rows of CBs on the panel. When it passes over the CB feeding the receptacle that the transmitter is plugged into, it emits an audible signal as well as illuminate the visual indicator. Like with the non-contact voltage detector, you don’t have to pull the cover on the power panel to use this instrument.
Hand tools that you will need
1. Straight-blade screwdriver
2. Phillips screwdriver
3. Needle nose pliers
4. Diagonal pliers
5. Wire strippers
6. Lineman pliers
Supplies that you will need
1. Plastic electrical tape, Scotch 33 is a good choice.
2. Red wire nuts
3. Yellow wire nuts
4. Green wire nuts
5. 120-Volt, 15 or 20-Amp, grounding receptacles.
6. Receptacle covers to replace broken or defaced covers.
7. Small spools of AWG 14 solid building wire in Black, White, and green colors.
What you’ve always wanted to know about receptacles but were afraid to ask.
Before we get started replacing receptacles, I want to take a couple of minutes of your time to talk about receptacles because there’s more to them then meet the eye. The first thing that I want to stress is that quality really counts where receptacles are concerned. From the front, an inexpensive receptacle may look the same as more expensive quality receptacle but they’re not the same inside or out. A quality receptacle has a metal strap that surrounds the back of the receptacle, running from plaster ear to plaster ear. On a cheap receptacle there is no strap connecting the plaster ears. The plastic components themselves are even sturdier on a quality receptacle.
Quality receptacles usually give you a choice of connecting the wires to screw terminals or using stab holes on the back of the receptacles but most cheep receptacles only provide stab holes. Stab holes make for quick connections but as any old time electrician will tell you, they are an accident waiting to happen so never use them. Take a little extra time and use the side-screw terminals. They are secure and safe and will be accepted by any electrical inspector.
Receptacles come in 15-Amp and 20-Amp sizes. From the front, you can tell them apart by their neutral slot, the longer of the two slots. The 15-A receptacle has a straight slot and the 20-A receptacle has a T-shaped slot. The receptacle’s Amperage rating is also stamped on the back of the receptacle. The thing to remember here, according to the NEC (National Electric Code), it is permissible to use a 15 or 20 Amp receptacle on a branch circuit protected by a 15 Amp CB or fuse but you can only use a 20-A (Ampere) rated receptacle on a branch circuit protected by a 20-A CB or fuse. If you don’t have a copy of this code, it would behoove you to add a copy to your library because the NEC is the Electrician’s Bible and all work has to be performed according to its rules and regulations.
On the sides of your receptacles, you will find five screws, two brass colored screws, two silver or white colored screws, and one green or blackish-colored screw. The two brass colored screws are the hot terminals and connect to the hot conductor, which is usually a black conductor but may be any color other than white, grey, or green. The silver or white colored screw connects to the circuit’s neutral or grounded conductor, which is usually white but may be a light gray in color. The circuit-grounding conductor, which may be a green insulated or bare conductor, connects to the green grounding screw.
Check to see if there’s an AL/Cu marking on the back of the receptacle. This stamping indicates that it can be used with either copper or aluminum conductors. If this marking is not present, the receptacle can only be used with copper conductors. Never under any circumstances use a receptacle designed for copper wire only with aluminum wire because it’s not only against the NEC, it’s a fire hazard. A galvanic reaction will take place between the dissimilar metals causing corrosion and heat build up which will cause a fire.
One more thing before we move on, on the back of all quality receptacles is a strip gauge that you can use to check and see if you have stripped enough or too much insulation from the conductors.
Making the connections.
When there are only two sets of cables entering the device box many electricians use the receptacle as a feed-through device, connecting the two neutral conductors to the two neutral screws and the two hot conductors to the two brass screws but this is not the best practice. Its good practice to get into the practice of “pig-tailing” all your connections unless it the last device on the circuit. Pigtails are nothing more than short pieces of wire that connect the device to the circuit conductors. Using the appropriate size wire nut connect all the black conductors entering the box together with a black pig-tail wire and do the same for the neutral conductors and grounding conductors. To make a good solid connection, hold the stripped conductor together so that ends are all even and then twist them together with your Lineman’s pliers. Once they are twisted together screw on the wire nut. Check to make that there’s no bare copper visible after the wire nut is firmly in place. If any copper is visible, remove the wire nut and cut the twisted joint back as needed. With the grounding conductor only, twist the ones entering the box together. After twisting them together, slip the grounding pigtail through the hole in the end of the green wire nut and then screw it on the splice.
Why use pigtails
That’s easy. If a receptacle is used as a feed through device and it is removed from the circuit without splicing the wires together will kill all the devices downstream from it. In other words, you will have many dead receptacles on your hands. With a pig-tailed receptacle, you can remove a receptacle without removing power to all the other receptacles downstream from it because you don’t have to break the circuit conductors feeding them.
Replacing the old receptacle
1. Using your new circuit tracer, locate and turn off the appropriate CB or remove the appropriate fuse. If possible, secure the panel so no one turns the circuit back on or replaces the fuse while you are working on the circuit. If you can’t secure the panel, place tape over the CB or fuse holder and place a note on the panel alerting everyone to the fact that you are working on the circuit.
2. Back at the receptacle use your non-contact voltage detector to make sure that the circuit is safe to work on.
3. Remove the receptacle cover, remove the two plaster ear screws and carefully pull the receptacle from the box, and disconnect the wires attached to it.
4. If the wires were connected to stab-holes, simply cut them as close to the old receptacles body as possible.
5. Cut three pigtails about 6”-8” long and strip the ends back 1”.
6. Form a loop on one end of the pigtails in a clockwise direction. The loop should extend ½ to 2/3 the way around each terminal screw. A clockwise loop will cause the wire to tighten around the screw as the screw is tightened. If a counterclockwise loop was used the wire would be forced out from under the screw as the screw is tightened.
7. Following the instructions given earlier connect the pigtails to the conductors entering and leaving the device box.
8. Carefully cover the receptacles terminals with tape. This isn’t required by code but its good practice because it will prevent accidental shorts from occurring between the hot terminal and a bare grounding conductor or with the side of a grounded metal device box.
9. Carefully push the receptacle into the device box and secure with the plaster ear screws.
10. Replace the receptacle cover, turn on the power, and check your work.
11. Be sure to check all the receptacles downstream from the one you replaced to be sure that they are all working properly.
