110.26
(C) Entrance to Working Space.
(1) Minimum Required.
At least one entrance of sufficient area shall be provided to give access to working space about electrical equipment.
(2) Large Equipment.
For equipment rated 1200 amperes or more that contains overcurrent devices, switching devices, or control devices, there shall be one entrance to the required working space not less than 610 mm (24 in.) wide and 2.0 m (61⁄2 ft) high at each end of the working space.
Where the entrance has a personnel door(s), the door(s) shall open in the direction of egress and be equipped with panic bars, pressure plates, or other devices that are normally latched but open under simple pressure.
A single entrance to the required working space shall be permitted where either of the conditions in 110.26(C)(2)(a) or (C)(2)(b) is met.
(a) Unobstructed Exit.
Where the location permits a continuous and unobstructed way of exit travel, a single entrance to the working space shall be permitted.
(b) Extra Working Space.
Where the depth of the working space is twice that required by 110.26(A)(1), a single entrance shall be permitted. It shall be located so that the distance from the equipment to the nearest edge of the entrance is not less than the minimum clear distance specified in Table 110.26(A)(1) for equipment operating at that voltage and in that condition.
