30 C.F.R. § 77.514 Switchboards; passageways and clearance.
Title 30 - Mineral Resources
Switchboards shall be installed to provide passageways or lanes of travel which permit access to the back of the switchboard from both ends for inspection, adjustment or repair. Openings permitting access to the rear of any switchboard shall be guarded, except where they are located in buildings which are kept locked.
Title 30: Mineral Resources
PART 77—MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES
Subpart F—Electrical Equipment—General
§ 77.514 Switchboards; passageways and clearance.

