General Installation Requirements, Part XXIII

Figure 1
Published On
Dec 15, 2016

The stated purpose of the National Electrical Code (NEC) is the practical safeguarding of people and property from hazards arising from electricity use. One way to help do this is to ensure there is enough room around electrical equipment.


As stated in 110.26, access and working space shall be provided and maintained about all electrical equipment to permit ready and safe operation and maintenance of the equipment. This is a general requirement saying access and working space must be provided and maintained, but it does not specify how much space has to be provided. Sections 110.26(A)(1) through (3) specify working space depth, width and height. 


Other topics in 110.26 include entrances and exits from working spaces, dedicated equipment spaces and electrical equipment rooms or enclosures housing electrical apparatus that are lock-controlled. One of the topics in this section, working space illumination, has nothing to do with minimum spacing around electrical equipment or minimum size/number of entrances and exits or even keeping the working space clear.


Working space illumination is covered in 110.26(D). Illumination shall be provided for all working spaces about service equipment, switchboards, switchgear, panelboards or motor control centers installed indoors. Just because this requirement is not the same as the requirements pertaining to minimum spacing around electrical equipment, does not mean it is 
less important.


This section states that illumination must be provided, but it does not state how much illumination has to be provided. This section does not specify minimum light levels such as foot-
candles. The next sentence in this section explains that, if adjacent lighting or lighting in the area illuminates the work space, additional lighting is not required (see Figure 1).


While it is not required to have extra lighting for the electrical equipment in the working space, it is certainly not prohibited. When working on or near energized electrical conductors or circuit parts, it is important to have plenty of lighting. Additional lighting may be necessary if a qualified person standing in front of electrical equipment is wearing an arc-rated face shield or arc-flash suit hood. For more information on this subject, see NFPA 70E, Standard for Electrical Safety in the Workplace. 


The first sentence in 110.26(D) also states the working-space illumination shall not be controlled by automatic means only. An occupancy sensor is one example of automatic means. This section does not say automatic means cannot be used to control lighting for the working area, but that the lighting must be controlled by some other way if an occupancy sensor is installed. In this case, some type of override is needed to ensure the lighting will not go off automatically.


For example, a panelboard is located in an area with one luminaire that provides illumination to the panelboard working space. The lighting fixture is controlled by a wall-mounted occupancy sensor. When the occupancy sensor is working properly, the working space light will be off until someone walks into the area. When the sensor detects the presence of a person, the light will turn on. A preset time after the person leaves the area, the light turns off. The working space illumination for this panelboard is controlled by automatic means, but it is also equipped with a means to override the automatic shutoff. Since illumination to this working space is not controlled by automatic means only, this installation is permitted (see Figure 2).


Section 110.26(D) also says additional lighting outlets are not required where the working space is illuminated as permitted by 210.70(A)(1), Exception No. 1. The requirement in 210.70(A)(1) states at least one wall-switch-controlled lighting outlet shall be installed in every habitable room and bathroom. The first exception to 210.70(A)(1) states, in other than kitchens and bathrooms, one or more receptacles controlled by a wall switch shall be permitted in lieu of lighting outlets. In a dwelling unit, it may be permissible to have a receptacle controlled by a wall switch in the area of 
working spaces. 


Section 110.26(E), Dedicated Equipment Space, is subdivided into indoor and outdoor installations. Section 110.26(A) contains requirements for equipment likely to require examination, adjustment, servicing or maintenance while energized, which includes a vast amount of equipment. Subsection 110.26(E) contains requirements for a very specific group of electrical equipment.


Although this section does not mention it pertains to equipment operating at 600 volts, nominal, or less to ground as it does in 110.26(A), the voltage threshold is the same because these requirements are in Part II, “600 Volts, Nominal, or Less.” As stated in 110.26(E), all switchboards, switchgear, panelboards and motor control centers shall be located in dedicated spaces and protected from damage. 


There are numerous places in the Code where requirements say to protect conductors and equipment from physical damage. A panelboard installed on a wall in a warehouse could be subject to physical damage. If so, it would need to be protected. Sometimes when panelboards are installed in industrial facilities, steel pipes or steel pipes filled with concrete are used to protect panelboards from hazards, such as tow motors. While this is a good way of providing protection for the panelboard, a violation could be created if the pipes are installed in a wrong location.


Physical protection, such as barriers and guards, shall not be installed within the working space of the panelboard; this includes depth of working space and width of working space (see Figure 3).


An exception under 110.26(E) states control equipment­—that by its very nature or because of other Code rules must be adjacent to or within sight of its operating machinery­—shall be permitted in those locations.


Next month’s column will continue the discussion of electrical installation requirements.

About the Author

Charles R. Miller

Code Contributor

Charles R. Miller, owner of Lighthouse Educational Services, teaches custom-tailored seminars on the National Electrical Code and NFPA 70E. He is the author of “Illustrated Guide to the National Electrical Code” and “Electrician's Exam Prep Manual.”...

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