SafetyQuestion 434 of 521
You are installing a 480Y/277V panelboard with exposed live parts likely to require examination while energized. There is a concrete (grounded) wall on the opposite side of the working space (Condition 1). What is the minimum working-space depth in front of the panel?
a.2 feet
b.2½ feet
c.3 feet
d.4 feet
Explanation
For nominal voltages of 151-600V, Condition 1 requires a minimum clear working-space depth of 3 feet in front of the equipment. The 3½- and 4-foot figures apply to Conditions 2 and 3 in that voltage range, and 2 or 2½ feet is never permitted for this equipment.
Law Reference: 2023 NEC §110.26Practice all 521 questions free — no signup required.
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