For equipment operating at 150 V or less to ground, under the least restrictive working-space condition (Condition 1), what is the minimum required depth of dedicated working space in front of the equipment?
Not quite. The answer is B: 3 feet
Table 110.26(A)(1) sets working-space depth at 3 ft for equipment at 0–150 V to ground, and at this lowest voltage band all three conditions (1, 2 and 3) require the same 3 ft. The conditions only separate in the 151–600 V band, where Conditions 2 and 3 require 3-1/2 ft and 4 ft. The 4 ft and 6 ft distractors come from carrying a Condition 2/3 number from a higher-voltage row down to this one. This value is the same in the 2020 and 2023 editions, so the answer holds for the exam and in the field.
Reference: NEC 2023 Table 110.26(A)(1) (Working Space — Condition 1)
Checked against multiple published sources
A SLAC safety document (2025, based on NFPA 70 110.26) and an ExpertCE article both give 3 ft depth for 0-150 V to ground in Table 110.26(A)(1). Neither names an NEC edition.