(3) Pit Areas in Lubrication or Service Room
(a) Ventilation Provided. The pit area shall be a Class I, Division 2 location where there is mechanical ventilation providing a minimum of six air changes per hour.
(b) Ventilation Not Provided. Where ventilation is not provided in accordance with 511.3(C)(3)(a), any pit or depression below floor level shall be a Class I, Division 1 location that extends up to the floor level.