IEEE C57.12.28-2005 IEEE Standard for Pad-Mounted Equipment—Enclosure Integrity.
4.1.3 Sharp corners External sharp corners and projections shall be minimized. 4.1.4 Panel assembly Panels shall be fastened or hinged to resist disassembly, breaking, or prying open from the outside with the doors in the closed and locked position. Normal entry shall be possible only with the use of proper access tools. There shall be no exposed screws, bolts, or other fastening devices that are externally removable (with the exception of pentahead bolts provided for extra security) that would provide access to energized parts in the enclosure. 4.1.5 Door hardware Locking bolts and associated threaded receptacles, hinges, and hinge pins shall be AISI type 304 stainless steel or material of equivalent corrosion resistance. 4.1.6 Handhole covers If handhole covers are exposed, they shall be secured from the inside of the enclosure. 4.1.7 Locking/latching devices The latching device(s) shall be designed and constructed of such a material so as to resist breaking or bending. The provision for locking device(s) on the enclosure door(s) shall be designed and located as to comply with the defined tests. 4.1.8 Enclosure access All access doors shall be fastened with a device that uses a pentahead tool to permit unlatching the door only after the padlock has been removed. This pentahead device or bolt shall be coordinated such that the padlock may not be inserted into the hasp until the access door is fully latched and the pentahead device is securely engaged. Enclosures without latches shall have padlock and pentahead bolt provisions and shall be coordinated to prevent insertion of a padlock until the access door is fully closed and the pentahead device or bolt is securely engaged. The padlock shall be removed before the pentahead bolt can be disengaged. A minimum of one pentahead device or bolt and padlocking means shall be provided. The pentahead device or bolt shall be surrounded by a nonrotating guard or shall be recessed such that the pentahead device or bolt can be engaged only by the proper tool.
IEEE C57.12.28 pdf download.