Basic Electrical Maintenance

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Key Questions

The following key questions are answered in this module:

What is a GFCI?
A Ground Fault Circuit Interrupter, or GFCI, is a safety device used in electric circuits. GFCIs are built into electrical outlets and they work by comparing the incoming current on the hot side with the outgoing current on the neutral side. They should be equal. GFCIs protect people from electric shock injuries and also protect the outlets, wiring, devices, and appliances from damage caused by overheating and fires due to ground faults and shorts.

What is an AFCI?
Arc Fault Circuit Interrupter, or AFCIs, also sometimes called Arc Fault Detection Devices, or AFDDs, are designed to detect and protect against potentially dangerous arc faults in addition to short circuits and overloads.

What are the three types of wires used in building electrical circuits?
The three types of wires used in building electrical circuits are hot, neutral, and ground. Hot wires (usually black) deliver current, while neutral wires (usually white or gray) create the current's return path. Ground wires (green or bare copper) prevent electrical fires and socks by providing an alternate safe path for the current.

What are the hazards of working on energized equipment?
Arc faults and arc flash are two potential hazards of working on energized equipment. An arc fault can occur when a conductive object contacts and bridges two conductors or a conductor and the ground. For voltages above 120v, this arcing can be in the form of an arc flash, where components explode violently.

When replacing an electrical receptacle, what is the correct wiring configuration?
The correct wiring configuration for an electrical receptacle is hot (black or colored) wires attach to brass screws, neutral (white) wires attach to silver screws, and green (ground) wire attaches to green screws.

Sample Video Transcript

Below is a transcript of the video sample provided for this module:

Electrical outlets should be replaced if they are sparking, getting hot, or no longer hold plugs securely. Outlets have screw terminals on the sides and, in some cases, the screw terminals have clamps. A thin, metal break-off tab connects the upper and lower terminals to supply current to both outlets, if desired. Break off the tab if you want to control the outlets separately. Like switches, hot wires connect to gold- or brass-colored terminals and ground wires connect to green terminals. Outlets also have silver terminals for the neutral wires. In 120v circuits, outlets at the beginning or middle of a circuit are connected to two hot wires and two neutral wires in order to continue the circuit, while outlets at the end of the circuit connect one hot wire and one neutral wire. Like a switch, you can use short pieces of wire to pigtail an outlet to the circuit in order to maintain the circuit if the outlet goes bad. To replace an electrical outlet: 1. Always wear appropriate PPE for the electrical equipment you will be working on. 2. Turn off the power and follow the appropriate lock-out tag-out procedure. Unscrew and remove the faceplate. Use a voltage tester or multi-meter to make sure the power is off. 3. Unscrew the outlet from the electrical box and pull it out with the wires attached. 4. Compare the old outlet to the new outlet and match up the wire connections. Also look to see if the metal tabs need to be broken off. 5. Disconnect the wires from the old outlet. 6. If needed, trim the wires and use a wire stripper to expose about ½-inch of wire on wires that will connect to the outlet, then use needle-nose pliers to form a loop at the end. 7. Starting with the ground wire, loop each wire clockwise around its terminal screw or insert it into the screw clamp and tighten the screw. If the electrical box is metal, join the circuit ground wire to two grounding pigtails; connect one pigtail to the outlet’s ground screw and the other to the electrical box’s ground screw. 8. Tuck the wires in behind the outlet, and then align and screw the outlet to the box. 9. Re-install the cover plate, and then turn the power back on.