Article 110 provides general requirements for all installations. Part II provides the requirements for systems operating at 1,000V (nominal) or less. And Part II begins with working spaces about electrical equipment [Sec. 110.26]. That’s a paragraph that is heavily revised from the 2023 edition. What’s been added is text requiring equipment doors not to impede ingress or egress.
An important, but often overlooked concept explicit in that first paragraph is that the working space around electrical equipment must permit “ready and safe operation and maintenance” of the equipment. All of the numerical requirements stated here are minimums. When property owners try to maximize revenue per square foot of a plant or other facility, they often treat these numbers as maximums or mere recommendations. The reality is some circumstances will require providing extra space rather than merely what is stated in the text or shown in a table.
If you don’t conform to the stated numbers, that’s an OSHA citation. If you do conform to the numbers but a reasonable person would conclude extra space is needed due to something about the application or equipment, that’s an OSHA citation. A company should always think of an OSHA citation as a certificate that reads, “We failed our employees.” Use sound engineering judgment.
The remainder of section Sec. 110.26 can also be found in the OSHA regulations, namely 1926.403. To their great credit, neither the current OSHA electrical manager nor his predecessor saw fit to develop something on their own and thus have conflicts, incompleteness, and errors. The approach taken was to codify into federal law the collective wisdom of the Code Making Panel members responsible for Art. 110. OSHA is also very aware that those panel members were not and are not working in an information silo. Thus, this particular wheel did not get reinvented by OSHA. If you have your dog-eared copy of the NEC handy, that’s all you need for discussing the OSHA regulations regarding working space.
A myth that just won’t die is the three foot rule. This rule holds that as long as you have three feet of empty space in front of a panel, you’re good. But people and equipment are three dimensional. Thus, you have work space requirements for depth [Sec. 110.26(A)(1)], width [Sec. 110.26(A)(2)], and height [Sec. 110.26(A)(3)]. What exactly these are depends on the characteristics of the specific application.
Table 110.26(A)(1) is a good general guide. The title of the table is “Working Spaces”, but in harmony with the admonition of Sec. 110.26 it provides the minimum distance. Not only is this the minimum distance, it is the minimum clear distance. Something barely jutting into this space is still in this space.
The table distances depend upon where there are exposed live parts in relation to the working space. If they are only on one side and the other side isn’t grounded the minimum clear distance is three feet. From there, that distance can be as high as five feet (exposed parts on both sides, 601V to 1000V). Three exceptions (Exception No. 1, 2, and 3) exist, and not necessarily to decrease the distance. For example, you follow the manufacturer’s space requirements for battery systems mounted on open racks.
If the equipment is in a limited access space (e.g., a ceiling space), you apply the requirements of Sec. 110.26(A)(4). You must keep equipment operating at or under 1000V separated from equipment operating at over 1000V if they certain conditions exist [Sec. 110.26(A)(5)]. You also must ensure the floor, grade, or working platform is as level and flat as practical and that it’s kept clear [1926(A)(6)].
Keeping it clear is second nature to some, but a real challenge to others. Don’t clutter your working space with packaging waste from the wiring or parts you’re using. Or anything else. This brings the need to apply some common sense that comes from Workmanship 101: Don’t work over yourself. You don’t want to be stepping on your tools, banging your hip into the maintenance cart, tripping on test equipment, or slipping on the door bolts you set on the floor. Keep things organized. And if you need extra space to work safely, then make or take that space.
