NEC 110.26 · 110.34 · 110.31 · 2023 NEC

How to apply NEC 110.26 working space around electrical equipment

Picking Condition 1, 2, or 3, measuring depth the way the inspector does, width, headroom, dedicated equipment space, and the over-1000 V rules — with worked examples and a free link to the official tables.

Need the actual tables? Look up Tables 110.26(A)(1), 110.34(A), and 110.31 in the free NFPA viewer →

How to read Table 110.26(A)(1), step by step

Step	What you do	Watch out for
1	Confirm the equipment is likely to need examination, adjustment, servicing, or maintenance while energized	Panelboards, switchboards, disconnects, MCCs, and control panels almost always qualify
2	Find the nominal voltage to ground (not phase-to-phase)	A 480Y/277 V system is read in the voltage-to-ground row that covers 277 V
3	Look at what is across from the equipment face and pick the condition	Concrete, block, brick, and tile walls count as grounded — that is Condition 2, not 1
4	Read the depth for that row and condition	Depth is measured from the exposed live parts, or from the enclosure front if the parts are enclosed
5	Apply width and headroom separately (110.26(A)(2) and (A)(3))	Depth, width, and height are three separate checks — passing one does not pass the others
6	Keep the dedicated equipment space above the gear clear of foreign systems (110.26(E))	Ducts, domestic water, drains, and gas piping are the usual violations (sprinkler protection itself is permitted)

Our own summary of the 2023 NEC, not the code text. Look up Table 110.26(A)(1), Table 110.34(A), and Table 110.31 in the free NFPA viewer (nfpa.org/freeaccess) and verify against the NEC edition adopted by your AHJ.

Which condition applies? (our paraphrase)

What is across the working space	Condition	Field examples
Exposed live parts on one side; nothing live or grounded on the other (or both sides guarded by insulating material)	Condition 1	Panel facing a drywall-on-wood-stud wall; gear facing an open area
Exposed live parts on one side; grounded parts on the other	Condition 2	Panel facing a concrete, block, brick, or tile wall; panel facing grounded metal equipment
Exposed live parts on both sides of the working space	Condition 3	Two switchboards or MCC lineups facing each other across an aisle

Depth increases from Condition 1 to 3 at the higher voltage rows; at the lowest voltage row the depth is the same for all three. Our own summary of the 2023 NEC, not the code text. Look up Table 110.26(A)(1), Table 110.34(A), and Table 110.31 in the free NFPA viewer (nfpa.org/freeaccess) and verify against the NEC edition adopted by your AHJ.

Worked example 1 — 480Y/277 V panelboard facing a CMU wall

Input / step	Value	Source
Voltage to ground	277 V	System is 480Y/277 V
What is across the aisle	Concrete block wall (grounded)	Field condition
Condition	Condition 2	110.26(A)(1)
Minimum depth	3½ ft	Table 110.26(A)(1)
Minimum width	30 in or the equipment width, whichever is greater	110.26(A)(2)
Result	Keep 3½ ft clear in front, 30 in wide, full headroom	—

Worked example values only. Look up the full table in the free NFPA viewer.

Worked example 2 — 208Y/120 V panel in a tenant storage room

Input / step	Value	Source
Voltage to ground	120 V	System is 208Y/120 V
Minimum depth	3 ft (same for every condition at this voltage row)	Table 110.26(A)(1)
Headroom	6½ ft or the equipment height, whichever is greater	110.26(A)(3)
Dedicated equipment space	Footprint of the panel, floor to 6 ft above the panel (or to the structural ceiling if lower)	110.26(E)(1)(a)
Result	No shelving in the 3 ft depth; the duct over the panel must be rerouted	—

Worked example values only. The owner will stack boxes there — mark the floor and put it in the closeout.

Which rule governs? (quick map)

Situation	Rule to open	What it controls
Equipment 1000 V nominal or less	110.26 and Table 110.26(A)(1)	Depth by voltage and condition, width, headroom, access, dedicated space
Large equipment (high ampacity and wide lineups)	110.26(C)(2)	When a second entrance or egress path is required
Equipment over 1000 V nominal	110.34(A) and Table 110.34(A)	Depth by voltage and condition — the same condition logic, larger depths
Outdoor over-1000 V yards behind a fence	110.31 and Table 110.31	Minimum distance from the fence to exposed live parts, by voltage
Existing dwelling service equipment, small ampacity	110.26(A)(3) exception	A headroom allowance for existing dwelling units — check the ampere limit in your edition

Common field mistakes

Mistake	What to do instead
Calling a concrete wall "Condition 1"	Concrete, block, brick, and tile are treated as grounded — Condition 2 at the higher voltage rows
Using phase-to-phase voltage to enter the table	Use the nominal voltage to ground
Measuring depth from the wall the panel is mounted on	Measure from exposed live parts, or from the enclosure front when they are enclosed
Letting the pipe fitter run a line through the dedicated space	Coordinate above-gear space on the MEP drawings before rough-in
Assuming the panel door can stop short of 90°	The working space must let hinged doors and panels open at least 90°

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Working space the inspector will pass

Look up Table 110.26(A)(1) in the free NFPA viewer. NFPA offers read-only access to current NEC editions at no cost. This page explains how to apply the rules; it does not reproduce the tables. Written to the 2023 NEC — verify against the edition your AHJ has adopted.

Depth is three variables. The table is entered with the nominal voltage to ground and the condition — what the worker has at their back. A drywall-on-stud wall is usually Condition 1; a concrete, block, brick, or tile wall is grounded and makes it Condition 2; gear facing gear is Condition 3. Depth is measured from the exposed live parts, or from the enclosure front when the parts are enclosed.

Width and headroom are separate checks. The working space must be at least the width of the equipment or a fixed minimum, whichever is greater, and doors or hinged panels must be able to open at least 90°. Headroom runs from the floor to a fixed minimum height or the height of the equipment, whichever is greater. Above the gear, 110.26(E) reserves a dedicated equipment space — the footprint of the equipment up to a set height — that foreign piping and ductwork cannot enter.

Over 1000 V is a different part of Article 110. Medium-voltage switchgear and transformers use 110.34(A), which applies the same three-condition logic with larger depths. Outdoor yards use 110.31, which sets how far the fence must stand from exposed live parts — for example, a 12.47 kV yard falls in the band that calls for 10 ft from fence to live parts. Look up the other voltage bands in the viewer.

Working space is cheapest to get right on paper. Coordinate electrical rooms on the MEP set before rough-in, lay out panels on a panel schedule template, and size the feeders with the NEC 310.16 ampacity chart and standard breaker sizes guide. Field PM keeps rough-in photos and inspection results with the job so clearance disputes are settled with a picture.

FAQ

How much clearance do I need in front of an electrical panel?+

It depends on the voltage to ground and what is across from the panel (Condition 1, 2, or 3) under NEC 110.26(A)(1). For a 208Y/120 V panel, the depth is 3 ft regardless of condition. Higher voltages need more depth when the opposite wall is grounded or has live parts. Width and headroom are separate checks. Look up Table 110.26(A)(1) in the free NFPA viewer at nfpa.org/freeaccess.

What is the difference between Condition 1, 2, and 3?+

Condition 1: live parts on one side and nothing live or grounded on the other. Condition 2: live parts on one side and grounded parts (including concrete, block, brick, or tile walls) on the other. Condition 3: live parts on both sides of the working space.

What is dedicated equipment space?+

Under 110.26(E), the space matching the equipment footprint, extending from the floor to a set height above the equipment (or the structural ceiling), is reserved for electrical installations. Foreign piping, ducts, and leak-prone equipment must not be installed there. Sprinkler protection is allowed.

Do the 110.26 working space rules apply above 1000 volts?+

No. Equipment over 1000 V nominal uses 110.34(A) and Table 110.34(A), which keep the same three-condition logic but call for greater depths. Outdoor fenced installations also use 110.31 to set the distance from the fence to live parts.

Does the 2023 NEC change 110.26?+

The core structure — voltage to ground, three conditions, width, headroom, and dedicated equipment space — carries through the 2020 and 2023 editions, with the dividing line between the 110.26 rules and the over-1000 V rules set at 1000 V. Section wording and exceptions are revised every cycle, so read the edition your AHJ enforces before you lay out an electrical room.

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