Features of the Textbook Features ur are student-focused learning tools designed gn to o help h you get the most out of your studies. This h is visual guide highlights the features designed for the te t ex tbook. Chapter Outline previews the topics to o be b learned in the chapter. Objectives clearly identify f y the knowledge and skills to be obtained when the ch c ha pter is completed. Technical Terms list the key terms to be learned in the chapter. te Safety Notes alert you to potentially dangerous materials and practices. Code Alerts point t out o sp s pe cific items from fi the National Electrical ct a l C Co de and typical building code d es . Cautions alert you to practices that could potentially d da mage ma equipment or instruments. viii Chapter Outline 12.1 Wiring Methods and Materials 12.1.1 Mechanical Considerations 12.1.2 Electrical Connections 12.1.3 Working Clearances 12.1.4 Identifification for Safety 12.2 Preparation of Conductors 12.2.1 Stripping Wire 12.2.2 Splicing Conductors 12.3 Wiring Switches and Receptacles 12.3.1 Switch Wiring 12.3.2 Receptacle Wiring 12.4 Wiring Circuits CHAPTER 12 Device Wiring Objectives Information in this chapter will enable you to: • Discuss the significance of listing or labeling electrical devices and materials. • Properly prepare conductors for connection to devices and equipment. • Make safe, secure conductor splices. • Demonstrate the proper method for attaching conductors to switches and receptacles. • Ground a receptacle. • Split-wire a receptacle. Ibthetheelectrician n fi nishing stages of a wiring project, fi makes the fi nal connection fi etween conductors and switches and recep- tacles as well as fi xtures, motors, and other fi devices. The NEC, specifi fically Article 1100, speci- fi es requirements for the installation of such fi materials and equipment. This chapter focuses on wiring switches and receptacles. Lighting is and 12.1 Wiring Methods and Materials the NEC. These articles describe, defi limit, fine, and specify the methods and materials of wir- ing used in the electrical industry today. Technical Terms break-off fin duplex receptacle grounding-type receptacle pigtail receptacle splicing split-wired receptacle wire connector CODE ALERT Avoiding Violationsonstialo A idi Vi Manyy common code violations are items cov- ered in Article 110 and Article 300, which cover uirement on wiring switches and receptacles. Lighti ng is hapter 13, Lighting Systems, , an d er 222 Motors. . A vo idi ng Vi l ti M an common co d e vio l ations are items cov- e r ed in A rticl e 11 0 a n d A rticl e 300 , which cover requirements for electrical installations and requir ements for wiring methods and me knowledgeable in s will be on wiring s covered in Chapter 13, g ter 22 Mot requ al requir ement ome kno w l ed ns wi ll be 44 Section 1 Fundamentals 3.4 Striking A hammer is used for driving nails and sta- ples, attaching hangers and electrical boxes, striking chisels, and driving ground rods. Many electricians prefer the electrician’s hammer to a standard claw hammer because r the electrician’s hammer has an extra long neck for driving nails through the bottom of an electrical box. The claw, which is straight rather than curved, is used to remove nails or loosen structural materials such as plaster during electrical remodeling. See Figure 3-18. A lineman’s is heavy enough to drive a ground rod.hammerr 3.5 Drilling Figure 3-17. Conduit benders are used for bending conduit on residential projects. A hickey is used to bend l arge-diameter or rigid conduit in muPublishersteps.most ltiple Klein Tools, Inc. Figure 3-18. Choose the correct hammer to make each task safer and easier. An electrician’s hammer has a long neck for mounting boxes and a straighter claw than a standard claw A lineman’s used for heavier work,hammer. such as driving a ground Electrician’s Hammer Claw Hammer Lineman’s Hammer Conduit Hickey Conduit Bender Goodheart-Willcox Appleton Electric Co. SAFETY NOTE Striking Tool Safety Here are l rules for th or the proper use use of strikingsomels:generaTips too • g t of Always choose the right ght size and we w eight ight o f ed use. hammer for the inten tend ed use • Never strike tools d • • on wiring c Mo req a l requiremen ome know l ed ns wi ll b o hapter g er 22 Mo requ me kno w l ed on wiring s Chapter 13, c g ter 22 Mot requ l requir eme ome kno w ns wi ll be Copyright Go odheart-Willcox Co., Inc. 3 . 5 3 . 5 Drilling Dri lli ng g g Electricians use a power drill/driverr for drilling holes i wood framing members, drilling pilot holes in n masonry, dri ving screws, and other basic t drill is the perfect choice for mucasks.ofAthcordless h work. In addition to a set of wood bits and masonry bits, a hole saw set may be need ed for cutting large holes in wood other soft materials. See Figure 3-19. traighter c l aw ammer. A l ineman ’ s hhammer ammer iis s for heavi er work , such as driving a ground rrod. od. g g t o f ed use. strike too l together l s t unless un l ess they are a re designe d for th r t hat purpose. se. For or example p l e hammer hea heads are hard rd ned an can shat- ter wheen n struck togetherenedagaind3caother, get her or gainst harden dene d tools. • Strik S triki ng tools should s shou l d strikke a e a surface squarely, nev neve r a r at an angle. ang • Always wear wear safetyy s gla g l asses when u en u n u n us ing strikinng kin g tools. too 118 Section Installation Copyright Goodheart-Willcox Co., Inc. Type THHN is the most common wire used in dry installations, while THWN is fre- quently used in wet installations. Refer to Table 310.104(A) for detailed information regarding insulation properties. 8.3 Conductor Size The size of the conductor to be used depends on the amount of electricity that must be con- ducted, the length of the conductor, and the type of environment in which the conductor will be used. Our discussion of wire sizes is limited to copper wire. For aluminum, a wire size larger than that for copper is always required. Refer to the NEC to determine the correct size. Goodheart-Willcox Publisher Figure 8-3. Wires may be covered by a variety of materials that protect the conductor and insulation. CODE ALERT Locations Explained The l ocation of an electrical ation is important, as certain may to be taken for the safetyprecautionsinstallneed of humans and the pres- ervation of the equip Article 100 of the NEC defines several imporment. tant location types: damp, dry, and wet. Location, Damp. Locations protected from weather and not subject to saturation with water or other liquids but subject to degrees of moisture. E e Outdomoderate or recep- tacle or light located an open porch area protectedfixtureroof.xamplin: by a Location, Dry. A location not norma ject to dampness or wetness. A l las- sified as may subject to dampnessdrywetnessbe,astemporarilyocationllycsub- or in the case of a build- ing under construction. E M devices, with the e some areas in bathroomspossiblexample: , garages,xceptionsostofindoor workshops, base- ments, etc. Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth in locations subject to satura- tion with water or other liquids, such as vehicle washing areas and in unprotected l ocations exposed to weather. Example: Security lighting or receptacles an exterior wall not under a roof. Landscapeon and deck lighting. Interior light fixtures in shower areas. Metal covering (armor)is Paper Conductor covered with THHN insulation Conductor covered with THHW insulationand CAUTION Pro Prop Prope er Wire r Wir S e Siz Siz e e Im I mpro mprope perly r l y sized si z z ed w d wire res s can can be b very e ve e very dangerous. angero If t I f the e wiress wires are a a too re too small ma ll, they they hey can ca heat heat up up and dest estroy oyy th the i he in sulation su l atio n. Thi T his T his could cou l d start art a fire or create create te a a shock a shock haaza z ard d. . Figure 8-4 shows the diameters of copper wires that are typically used in residential wir- ing. There are two units of measure for designat- ing the sizes of these wires, the fi rst being the fi American Wire Gage (AWG) . The smallest wires in residential wiring are 18 AWG to 1 AWG. The larger the number, the smaller the diameter. 3 . 5 Dri lli ng gether hey a n m h e en n re ys n ns rances cation ion of 2 . 2 . 1 12 I n dampnes s or we tness , as in t he case of a bui l d