Electric ch 2 Quizlet
"BX" cable is the trade name used for Type __________ cable. Article __________ of the NEC® covers this cable type.
BX cable is the trade name used for Type AC cable. Article 320 of the NEC covers this cable type.
Describe what "ganging" electrical device boxes is and what purpose ganging electrical device boxes serves.
Ganging is the joining together of two or more device boxes for the purpose of holding more than one device. For example, two switches may be required beside the front door of a house. One switch is required to control an outside light and the other switch is necessary to control the lighting in the room. For this situation the electrician would need to gang together two single-gang metal device boxes to make a two-gang device box.
Describe how an electrician can tell Type AC and Type MC cable apart.
One of the easiest ways to determine if a cable is Type AC or Type MC is to look at how the conductors in the cables are wrapped. Type AC cable has a light brown paper covering each conductor while Type MC has no individual wrapping on the conductors. There is polyester tape over all of the conductors in Type MC cable, and usually Type MC has no aluminum bonding wire in it. However, a newly introduced Type MC cable does have an aluminum bonding wire in it but the conductors are still wrapped with a polyester tape.
Describe a combination device.
Combination devices are used when more than one device is needed at one location. This type of device has a combination of two devices, both of which are mounted on the same strap. It may be a combination of two single-pole switches, a single-pole and a three-way switch, a single-pole switch and a receptacle, or even a switch and a pilot light.
Discuss when an electrician would use a "new work" box and an "old work" box.
Electrical boxes with mounting ears are typically called "old work" boxes because the ears allow thein to be installed in an existing wall. Electrical boxes without the mounting ears are referred to as "new work" boxes and are used when installing an electrical system in a new home.
An electrician needs to mount a chime on a sheetrock wall. Name three anchor types described in this chapter that could be used.
Three common anchors that could be used to mount a chime on a sheetrock wall are: (1) toggle bolts; (2) wallboard anchors; and (3) molly bolts (also called sleeve type anchors). Plastic anchors are sometimes used but care must be used to not mount very heavy items with them, since they pull out of a sheetrock wall quite easily. Make sure to follow the manufacturer's recommendations when installing anchors in hollow walls and ceilings.
List three nationally recognized testing laboratories.
Three nationally recognized testing laboratories (NRTL) are: (1) Underwriters Laboratories Inc. (UL); (2) CSA International (formerly Canadian Standards Association); and (3) Intertek Testing Services (formerly Electrical Testing Laboratories).
Describe when three-way switches would be used in a residential lighting circuit.
Three-way switches are used to control a lighting outlet or outlets from two locations. An installation example would be in a living room that has two doorways. One three-way switch would be located next to one doorway and another three-way switch would be located next to the other doorway. A person entering or leaving the living room can turn the lighting outlet(s) in that room on or off from either doorway.
List the two types of plug fuses.
Two types of plug fuses used in residential electrical installations are the Edison base plug fuse and the Type S plug fuse.
Name and describe three cable types that can be used in residential electrical installations.
- Nonmetallic sheathed cable (Type NM)—a factory assembly of two or more insulated conductors having an outer sheathing of moisture-resistant, flame retardant, nonmetallic material. It is available with two or three conductors in sizes from 14-AWG through 2-AWG copper and 12-AWG through 2-AWG aluminum. - Underground feeder cable (Type UF)-used for underground installations of branch circuits and feeder circuits. It can also be used in interior installations but must be installed following the installation requirements for nonmetallic sheathed cable. It is available in wire sizes from 14-AWG through 4/0-AWG copper and from 12-AWG through 4/0-AWG aluminum. - Armored-clad cable (Type AC)-a fabricated assembly of insulated conductors in a flexible metallic enclosure. It is available with two, three, or four conductors. A small aluminum bonding wire is included and is used to ensure electrical continuity of the outside flexible metal sheathing. Type AC is also available with a green insulated grounding conductor. It is available in wire sizes 14-AWG through 1-AWG copper and 12-AWG through 1-AWG aluminum.
List four raceway types described in this chapter that could be used in residential wiring.
- Rigid metal conduit (RMC) - Intermediate metal conduit (IMC) - Electrical metallic tubing (EMT) - Rigid PVC conduit (PVC)
An electrician installs a 4-inch square box in a location that requires a duplex receptacle. Describe what must be done so that the duplex receptacle can be installed in the square box.
A 4-inch square box installed in a wall requires a special mounting cover called a "raised plaster ring" or "raised mud ring," If a 4-inch square box is surface. mounted, a "raised cover" is required to allow the installation of a duplex receptacle. This is the same method used to install switches in a 4-inch square box.
Describe a loadcenter.
A loadcenter is a type of electrical panel that contains the main disconnecting means for the residential service entrance as well as the fuses or circuit breakers used to protect circuits and equipment like electric water heaters, ranges, dryers, and lighting. Most loadcenter are placed inside a dwelling unit and are typically. a.NEMA Type 1 enclosure. NEMA 1 enclosures are the most commonly used type of enclosure in residential wiring and are designed for use indoors under usual service conditions.
Describe a powder-actuated fastening system.
A powder-actuated fastening system uses a tool specifically designed to use the force of a gunpowder load to drive a fastener into concrete or steel. The depth to which a stud or pin is driven depends on the strength of the gunpowder load and the density of the material on which you are installing. The different powder loads are color coded, and it depends on the specific manufacturer as to what color code is being used. Consult the manufacturer's instructions. OSHA CFR 1926.302(e) governs the use of powder-actuated fastening systems and requires special training and certification before an electrician is allowed to use this type of fastening system. Usually a manufacturer of this type of system will provide training and certification.
Define the term "receptacle."
A receptacle is defined as a contact device installed at the outlet for the connection of an attachment plug. Even though many people, including electricians, refer to a receptacle as an "outlet," it is the wrong term to use. An outlet is the point on the wiring system at which current is taken to supply equipment. A receptacle is the device that allows us to access current from the wiring system and deliver it through a cord and attachment plug to a piece of equipment.
A single-pole circuit breaker is used on a circuit voltage __________ of volts, and a two-pole circuit breaker is used on a circuit voltage of __________ volts in residential wiring.
A single-pole circuit breaker is used on a circuit voltage of 120 volts, and a two pole circuit breaker is used on a circuit voltage of 240 volts in residential wiring.
Name the system that is used to size the conductors used in electrical work.
The American Wire Gauge (AWG) is the system used to size the conductors used in residential wiring. In this system, the smaller the number, the larger the conductor; and the larger the number, the smaller the conductor. The National Electrical Code recognizes building wire from 18-AWG up to 4/0. 1/0,2/0,3/0, and 4/0 are sometimes shown as 0,00, 000, and 0000, respectively. Electricians pronounce these wire sizes as 1 "aught," 2 "aught," 3 "aught," and 4 "aught." Conductor sizes larger than 470 are measured in circular mils. A komil is 1000 circular mils.
Conductors used in residential wiring are selected for a specific circuit according to their ampacities. Define the term "ampacity."
The ampacity of a conductor refers to the ability of a conductor to carry current. The current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating is how the term ampacity is defined in the NEC®. The larger the conductor size, the higher the ampacity is of the conductor.
Name the insulation colors of the wires found in a three-wire, nonmetallic sheathed cable.
The colors of the wires found in a three-wire nonmetallic sheathed cable are black, red, and white. There is also a bare grounding conductor in the cable.
Name the size of machine screw that is used to secure switches and receptacles to device boxes.
The size of machine screw used to secure switches and receptacles to an electrical device box is 6-32
Name the size of the most common metal electrical device box used in residential wiring.
The size of the most common metal electrical device box used in residential wiring is a 3- X 2- X 344-inch (75- X 50- X 90-mm) device box
Name the trade name used for flexible metal conduit.
The trade name that electricians use for flexible metal conduit (FMC) is Greenfield
Describe the difference between Type SEU and Type SER cable in terms of physical characteristics.
Type SEU cable contains three conductors enclosed in a flame-retardant, moisture-resistant outer covering. The service neutral conductor is made up of several bare conductors wrapped around the insulated, ungrounded conductors. Type SER cable is similar to Type SEU but has four conductors wrapped in a round configuration. The neutral conductor is insulated and the cable also contains a bare grounding conductor.
Type UF cable is used in __________ installations for branch circuits and feeders. Article __________ of the NEC® covers Type UF cable.
Type UF cable is used in underground installations for branch circuits and feeder circuits, Article 340 of the NEC® covers Type UF cable.
The approval of electrical equipment by the authority having jurisdiction is often based on the listing and labeling of the product. Describe what "listing" and "labeling" electrical equipment means.
When an electrical product is listed, it means that the product has been put on a list published by an NRTL. The independent testing laboratory evaluates the product, and if the product meets a series of designated standards, it is found suitable for its intended purpose and is placed on the list. A label is put on the equipment, or on the box that it is packaged in if the item itself is too small to accommodate a label. This is the identifying mark of a specific testing laboratory. The label allows an electrician, or more importantly the authority having jurisdiction (AHJ), to see that the product complies with appropriate standards. If the product is installed and used according to the installation instructions, it will work in a safe manner.
