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Chapter 7 — Printreading Applications  251

• Smoke detectors and carbon monoxide detectors shall activate all alarms, be wired for primary and battery-operated for secondary power. A combination smoke / carbon monoxide (CO) detection unit is available for applications in which both detection units are required. The presence of CO is possible when using natural-gas household equipment such as boilers, central heating systems, water heaters, and cookers. Open fires, which use gas, oil, coal, or wood as fuel, may also be sources of CO if the fuel does not burn completely. Venting gas appliances according to manufacturer instructions is important, and proper maintenance ensures a safe home environment. • At least one electrical receptacle in addition to those used for connections must be provided in each basement. For each unfinished basement, there shall be at least one GFCI receptacle. Some basements include finished spaces for added entertainment or family-room areas. If the portion of the finished area creates more than one unfinished basement space, at least one receptacle is required in each unfinished basement space. • The basement-stair light fixture is to have a threeway switch at the top and bottom of the stairway. It is common to have two three-way switches that control one or more stairway light fixtures. This enables the user to turn the lights on before walking up or down the stairs and turn the lights off once reaching the top or bottom of the stairs. • All closet lights shall be plunger-switched to turn on when the door opens. Plunger switches are convenient and eliminate the use of wall switches. See Figure 7-15. Clearance of 6″ must be maintained between any light fixture and the nearest point of storage space. • All light fixtures above the whirlpool, tubs, and showers shall be GFCI-protected. Light fixtures located within 8′ of the top rim of a tub or shower stall shall be marked for damp locations or marked for wet locations where subject to shower spray. A designer can exceed the NEC® standard and require all light fixtures in this space to be GFCI-protected. Some light fixtures and combination lighting exhaust fans are marked for use in shower or tub areas and require GFCI protection according to the manufacturer. Section 110.3(B) states that listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or on the label.



Figure 7-15. Plunger switches provide a convenient switch option, but the door must be closed when exiting the closet in order to turn off the light.

• All branch circuits that supply 125 V, single-phase, 15-amp and 20-amp receptacle outlets installed in dwelling unit bedrooms shall be protected by an arcfault circuit interrupter (AFCI). AFCI technology began in the 1990s and first appeared in the 1999 NEC®, but mandatory use was not enforced until January 1, 2002. An AFCI is intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by de-energizing the circuit when an arc fault is detected. The first device was in the form of a circuit breaker installed at the origin of the branch circuit. For branchcircuit extensions or modifications, a listed receptacle branch-circuit AFCI located at the first receptacle of the existing branch circuit can be used. T E C H FAC T In 1961, the GFCI was invented by Charles Dalziel who was a professor of electrical engineering at the University of California.

Printreading Based on the 2017 NEC®  
Printreading Based on the 2017 NEC®  

Printreading has been updated to reflect changes in the NEC® and incorporates fundamental printreading skills and relevant NEC® topics. Prin...