210.70 Lighting Outlets Required
The National Electrical Code states its purpose as “the practical safeguarding of persons and property from hazards arising from the use of electricity.” [90.1(A)] The adequacy of the Code is covered in 90.1(B). Some key points covered in this section include: 1) provisions contained in the Code are considered necessary for safety; 2) while proper maintenance and compliance with the Code will result in an installation that is essentially free from electrical hazards, it will not necessarily be efficient, convenient or adequate for good service; and 3) provisions in the National Electrical Code do not necessarily provide for future expansion of electrical use. Although planning for future electrical use is not required, we are not limited to the minimum requirements either.
Receptacle and lighting outlet requirements are covered in Article 210. All occupancies are covered, but many of these provisions pertain to dwelling units. Last month’s In Focus began a new series covering required lighting outlet provisions. The series began with a discussion of related terminology from Article 100; then discussed some associated provisions from Articles 314 and 422. This month’s In Focus resumes with 210.70.
As stated in 210.70, lighting outlets must be installed in accordance with the provisions in 210.70(A), (B), and (C). These three subsections contain requirements for dwelling units, guest rooms (hotel, motel, or similar occupancies) and certain areas in non-dwelling occupancies. Required lighting outlet provisions for dwelling units are divided into three subsections under 210.70(A). They include: habitable rooms, additional locations and storage (or equipment) spaces. The first subsection covers lighting outlet provisions for habitable rooms (and bathrooms). The second contains requirements for hallways, stairways and garages. The last subsection under 210.70(A) covers attics, underfloor spaces, utility rooms and basements.
Lighting outlets in dwelling units must be installed in accordance with 210.70(A)(1), (2) and (3). At least one wall-switch-controlled lighting outlet must be installed in every habitable room (and bathroom) of a dwelling [210.70(A)(1)]. This provision requires at least one lighting outlet in every habitable room and at least one wall switch to control it. The dictionary defines habitable as “fit to be lived in.” Habitable rooms include, but are not limited to: kitchens, breakfast areas, dining rooms, family rooms, great rooms, bonus rooms, sitting rooms, living rooms, parlors, libraries, dens, sunrooms, bedrooms, recreational rooms, etc. Unless meeting one of the two exceptions, at least one lighting outlet controlled by a wall switch is required in every habitable room. (See Figure 1.)
As stipulated in 90.1(C), the Code is not intended as a design specification. Therefore, the exact height of a wall switch is not specified. While the lighting outlet must be located within the room, the switch’s location is not stipulated. The wall switch can be installed inside or outside the room. Most of the time, the wall switch is located in the room and within reach upon entering the room. Sometimes the wall switch is located just outside the room. For example, a kitchen in a dwelling unit has lighting outlet in the center of the room. No door will be installed in the kitchen’s entrance. On the left side of the entry is a pantry, and just beyond it is the refrigerator. There is no room for the switch on the left side. On the right side is the electric range. On the wall behind the range is a metal backsplash. Because of this design, there is no convenient location for the wall switch in the kitchen. The switch will be installed on the wall just outside the kitchen’s entrance. (See Figure 2.)
While the Code does not require more than one wall switch in each room, additional switches are often installed in rooms having more than one door (or entry). For example, a living room in a dwelling has three entry points. Although only one switch is required, the electrical contractor will install three. This room’s lighting will be controlled by two three-way and one four-way switch. (See Figure 3.) Some state and local jurisdictions may require additional wall switches in rooms having more than one door (or entry). Obtain a copy of any additional rules and regulations for your area.
Two exceptions are under the requirement pertaining to habitable rooms. Except for kitchens and bathrooms, one or more receptacles controlled by a wall switch may be installed in lieu of a lighting outlet [210.70(A)(1) Exception No. 1]. If the wall switch controls one or more receptacles, no lighting outlet is required. For example, a wall switch installed in the living room will control the bottom half of each duplex receptacle in that room. Because of the switched receptacles, no lighting outlet is required. (See Figure 4.)
Wiring a receptacle so that one half is a typical receptacle and the other half is controlled by a switch is commonly called a split-wired receptacle. The tab on the side is removed so one receptacle can be controlled from the wall switch and the other can remain energized, whether the switch is on or off. (See Figure 5.) Split-wired receptacles can be supplied from a single source (one breaker or fuse) or more than one source. A split-wired receptacle supplied from a single source is not a multiwire branch circuit. Therefore, compliance with multiwire branch-circuit requirements is not necessary.
Split-wired receptacles supplied from a multiwire branch circuit must be installed in accordance with provisions in 210.4(B) and 300.13(B). A multiwire branch circuit consists of two or more ungrounded (hot) conductors and one grounded (neutral) conductor. In dwelling units, if a multiwire branch circuit supplies more than one device (or equipment) on the same yoke, a means must be provided to disconnect all ungrounded (hot) conductors simultaneously. This simultaneous disconnecting means must be located in the panelboard where the branch circuits originate [210.4(B)]. For example, a dwelling unit contains a split-wired receptacle that is supplied from a multiwire branch circuit. One circuit supplies the outlet that is controlled by a wall switch. The other circuit feeds the other outlet. Since this multiwire branch circuit supplies one device on the same yoke, a means must be provided to disconnect both circuits at the same time. This can be accomplished by using either one double-pole circuit breaker, or two single-pole breakers with approved tie handles. (See Figure 6.) In multiwire branch circuits, the continuity of a grounded conductor must not depend on device connections such as receptacles, lampholders, etc., where the removal of such devices would interrupt the continuity [300.13(B)].
The first exception under 210.70(A) does not stipulate a maximum or minimum number of switched receptacles. In Figure 4, the bottom half of each living room receptacle is switched. This exception is met even if only one half of one duplex receptacle is controlled by the wall switch. The location of the switched receptacle is not specified either. The switched receptacle could be below the switch, on the far side of the room, or anywhere in between.
Next month’s In Focus will continue discussion of required lighting outlets in dwelling units 210.70(A)(1). EC
MILLER, owner of Lighthouse Educational Services, teaches custom-tailored classes and conducts seminars covering various aspects of the electrical industry. He is the author of Illustrated Guide to the National Electrical Code. For more information, visit his Web site at www.charlesRmiller.com. He can be reached by phone at (615) 333-3336, or via e-mail at charles@charlesRmiller.com.