Electrical space: the final frontier where electrical inspectors voyage to explore two of the many requirements of section 110.26(A)
Electrical space: the final frontier. “These are the voyages of the electrical inspector.” This plays on a quote from one of my favorite Star Trek movies. Space, especially electrical equipment space in buildings, can seem like it is a final frontier because it is getting harder to come by. Or is it? Prior to the COVID outbreak, buildings were being built to house hundreds, even thousands of employees, so space for electrical and mechanical rooms was at a premium and in tight quarters. Office space, especially when being rented by the square foot, was made a higher priority. With the way that many of us work shifting due to the pandemic, designs of buildings are likely to also start shifting to accommodate the move to a more remote workforce, which occupies less space within buildings. This may cause office spaces to be consolidated, therefore giving more room for electrical and mechanical rooms. Consolidation of space for offices may be occurring, but the change in how we work appears aimed more at having open spaces being converted to conference rooms for team meetings. But no matter what is occurring in the space designated for offices or meeting rooms, the one area that cannot be compromised is the spaces about electrical equipment. There are two types of spaces around electrical equipment mentioned in the 2023 National Electrical Code® (NEC®): working space and dedicated equipment space. Each one has quite different requirements, but all aid in the safety of the worker and longevity of the installation.
Working space within the NEC, in general, is comprised of three parts:
- Depth of Working Space - found in section 110.26(A)(1). This measurement factors in nominal voltage to ground and if there are grounded parts or exposed live parts across from the equipment. Measurements are taken from live exposed parts or from enclosure if live parts are enclosed, out the front until the minimum distance found in Table 110.26(A)(1) is met.
- Width of Working Space –in section 110.26(A)(2). This dimension is derived by measuring the width across the front of the equipment. This can be taken from center (15 inches in middle of equipment), from left side of equipment or from right side. No matter the voltage or amperage the width will never be less than 30 inches.
- Height of working Space – addressed in 110.26(A)(3). This is measured from grade, floor, or platform to a height of 6.5 feet and is the width of the equipment or minimally 30 inches.
All these spaces combine to form a box, if you will, that is for the qualified worker to occupy when servicing or working on the equipment. This is intended to provide room to move, which is necessary to keep them from bumping into something and possibly getting shocked or causing an arc flash. This area also allows easy access to equipment should a breaker or disconnect need to be shut off quickly. Working space is not to be used for storage according to 110.26(B). In all my years as an inspector I can’t tell you how many times I have had to write that violation during the electrical inspections. These mostly occurred on remodels where circuits and wiring were added to the existing electrical systems. I would politely remind the building owner/occupant that working space was required to help keep the electrical worker safe from exposure to electrical hazards that may be present. New to the 2023 NEC in section 110.26(A)(6) is the requirement that the grade, floor or platform in the working space be clear and as level or flat as practical for the entire required depth and width.
The dedicated equipment space in 110.26(E) is just what you would think it would be; space dedicated solely for the installation of electrical equipment. Indoor dedicated electrical space is found in 110.26(E)(1)(a), which electrical inspectors often refer to as the “thumb print” of the equipment plus six feet above the top of the equipment. For example, a panelboard 20-inches wide x 6-inches deep mounted to the surface of the wall at seven feet to the top would have dedicate electrical space extending up to 13 ft above the finished floor. So the overall dedicated space is 20-inches wide x 6-inches deep up to 13 ft. In general, only electrical items are allowed within that space, which might include:
- raceways (and associated fittings)
- junction boxes
This list is not all inclusive, but an idea of what may be seen within the vicinity of electrical equipment. One exception to the dedicated space requirement is made for suspended ceilings with removable panels. With design limitations imposed on room size, there may be the occasional foreign system intruding into the dedicated electrical space required by section 110.26(E)(1)(a), typically becoming a violation. So, if the system was installed in accordance with 110.26(E)(1)(b), which addresses foreign systems over the dedicated electrical space, there would not be a problem. Remember our example, the top of the dedicated electrical space was 13 feet above finished floor, so the foreign system would need to be higher than 13 feet. If a foreign system is subject to condensation or leaks, the electrical equipment would require protection from such occurrences, which may also mean the system needs to be higher since the method of protection is not allowed within the dedicated electrical space. This space was put into the code to ensure adequate access to the electrical system for the installation of associated parts and to protect the electrical installation from other systems foreign to the electrical system.
Electrical space: the final frontier where the voyages of the electrical inspector have explored two of the many requirements of section 110.26(A).