110.26
Spaces About Electrical Equipment (Working Space)
Working space exists to keep electricians alive. When you open a panel, switchboard, or disconnect while it is energized, you need enough room to stand safely, use tools without bumping into grounded surfaces, and escape quickly if an arc flash occurs. Section 110.26(A)(1) sets the depth of working space using Table 110.26(A)(1), which defines three conditions based on what is on the opposite side of the working space. Condition 1 is exposed live parts on one side with no live or grounded parts opposite (or both sides effectively guarded by insulation) — minimum 3 feet for 0 to 150 volts. Condition 2 is exposed live parts on one side with grounded parts opposite (such as a concrete block wall or grounded metal) — also 3 feet for 0 to 150 volts. Condition 3 is exposed live parts on both sides — also 3 feet for 0 to 150 volts. For 0 to 150 volts all three conditions require the same 3-foot minimum. For 151 to 600 volts, the depths are 3 feet (Condition 1), 3.5 feet (Condition 2), and 4 feet (Condition 3). For 601 to 1000 volts, the depths increase to 3 feet, 4 feet, and 5 feet respectively. Section 110.26(A)(2) requires the width of the working space to be at least 30 inches or the width of the equipment, whichever is greater, and the space must permit at least a 90-degree opening of the equipment door or hinged panel. Section 110.26(A)(3) sets the minimum height at 6 feet 6 inches or the height of the equipment, whichever is greater. Section 110.26(B) requires the working space to remain clear and not be used for storage. Section 110.26(C) addresses entrances — for equipment rated 1200 amps or more and over 6 feet wide, two entrances are required (one at each end of the working space), unless unobstructed egress exists or the depth of working space is doubled. Personnel doors within 25 feet of equipment rated 800 amps or more must open outward and be equipped with listed panic hardware. Section 110.26(E) requires dedicated equipment space above panelboards and switchboards — nothing unrelated (like plumbing, ductwork, or sprinkler piping) is permitted in the zone extending from the floor to 6 feet above the equipment or the structural ceiling, whichever is lower.
When You Need This
- Installing a new electrical panel, switchboard, or motor control center and verifying there is enough clearance in front of and around the equipment
- Inspecting an existing installation where storage, shelving, or building systems have encroached into the required working space
- Designing an electrical room layout for a commercial or industrial building and ensuring adequate entrances and dedicated equipment space
- Responding to an inspector's citation for a working-space violation — this is one of the top-five most cited NEC violations nationwide
- Studying for any electrician licensing exam — 110.26 questions appear on virtually every test at every level
Key Points
Common Mistakes
Using the panel area as storage — stacking boxes, tools, or materials in front of electrical equipment is the single most common NEC violation in commercial and industrial facilities
At 151-600V, confusing the three conditions and applying Condition 1 depths (3 ft) when a concrete block wall or grounded metal surface opposite the panel makes it Condition 2 (3.5 ft) — at 0-150V all conditions are 3 ft, so this mistake matters most at higher voltages
Measuring the 3-foot depth from the wall behind the panel instead of from the exposed live parts or the front opening of the enclosure
Forgetting the 30-inch width minimum — a panel squeezed into a 24-inch closet violates the code even if the depth is adequate
Not providing panic hardware on personnel doors within 25 feet of equipment rated 800 amps or more
Running water pipes, HVAC ducts, or sprinkler lines through the dedicated equipment space above a panelboard
Exam Tip
Memorize the table: for 0 to 150V, all three conditions require 3 ft. For 151 to 600V: Condition 1 = 3 ft, Condition 2 = 3.5 ft, Condition 3 = 4 ft. For 601 to 1000V: 3 ft, 4 ft, 5 ft. Width = 30 in. or equipment width. Height = 6.5 ft or equipment height. For the entrance question, remember: 1200A and over 6 ft wide = two exits required. Personnel door panic hardware = 800A and within 25 ft. The exam frequently tests whether you know the difference between Conditions 1, 2, and 3.
Frequently Asked Questions
Condition 1: exposed live parts on one side, no live or grounded parts on the other side (or insulated/guarded). Condition 2: exposed live parts on one side, grounded parts on the other side (concrete wall, grounded metal, etc.). Condition 3: exposed live parts on BOTH sides of the working space. Each condition requires progressively more depth to protect the electrician.
Yes, if the closet provides the full required working space: at least 30 inches wide (or the panel width, whichever is greater), the correct depth for the applicable condition (usually 3 feet for Condition 1), and at least 6 feet 6 inches of headroom. The closet also cannot be used for storage, and the panel must have dedicated equipment space above it free of plumbing and HVAC.
Yes. Section 110.26 applies to all electrical equipment likely to be examined, adjusted, or maintained while energized — including residential panels. You cannot park a car within the 3-foot working space in front of the panel. At 0 to 150 volts (typical residential), all three conditions require 3 feet. If the voltage is 151 to 600 volts and the opposite wall is concrete block (grounded surface), Condition 2 applies and you would need 3.5 feet.
Related Code Sections
This is an educational summary, not the official code text. The NEC® is a registered trademark and copyright © National Fire Protection Association (NFPA). The CEC is copyright © CSA Group. For official code text, visit nfpa.org or csagroup.org. SparkShift is not affiliated with NFPA or CSA Group.