Working Space Clearances and Panelboard Location Rules
Panels and equipment have to be reachable and serviceable safely. Two sections govern: 110.26 (the clear space around equipment) and 240.24 (where overcurrent devices may and may not go).
1. Working space — the "3 / 30 / 6.5" you must know (110.26)
For equipment likely to be examined or serviced while energized:
| Dimension | Requirement | Section |
|---|---|---|
| Depth (in front) | 3 ft (Condition 1, 0–150 V to ground) | 110.26(A)(1) |
| Width | 30 in, or the width of the equipment — whichever is greater | 110.26(A)(2) |
| Headroom (height) | 6.5 ft (6 ft 6 in) | 110.26(A)(3) |
Depth grows for higher voltages and worse "conditions" (grounded or live parts on the other side), per Table 110.26(A)(1) — but for ordinary 120/240 V dwelling panels, it's 3 feet.