Disconnecting Means and Working Space: What Must Be In Sight and Why

Regulation: NEC Articles 110, 404, 430

Keywords: NEC working space requirements, disconnecting means in sight, NEC 110.26 working space, electrical panel clearance NEC, within sight NEC definition, motor disconnect in sight, NEC dedicated electrical space, headroom electrical equipment

Core Concepts

• Working Space Depth: Depends on voltage and conditions. Condition 1 (grounded surfaces): 3 ft for 0–150V, 3.5 ft for 151–600V. Condition 2: 3.5 ft / 4 ft. Condition 3 (live on both sides): 4 ft / 5 ft.
• Working Space Width and Height: Width: minimum 30 inches or equipment width, whichever is greater. Height: minimum 6.5 ft or equipment height, whichever is greater.
• Within Sight Definition: NEC defines within sight as BOTH visible AND within 50 feet. Both conditions must be met simultaneously.
• Dedicated Electrical Space: Space above electrical equipment to structural ceiling (or 25 ft, whichever is less) must be dedicated to electrical use — no foreign piping, ducts, or systems.

Exam Traps

• 'Within sight' requires BOTH visible AND within 50 feet — one condition alone does not satisfy the requirement.
• The working space in front of a panel cannot be used for storage — ever.
• A motor controller disconnect can be out of sight of the motor IF the disconnect is lockable in the open position.
• Dedicated electrical space and working space are two different zones — dedicated space is above; working space is in front.
• A door opening into working space must open at least 90 degrees and must not reduce the required clearance when open.

Memory Aid

Within sight = visible + ≤50 ft. Depth = 3/3.5/4 ft by condition. Width ≥30 in. Height ≥6.5 ft. Nothing stored in front of panels.