Article 100 Definitions. Guarded. Covered, shielded, fenced, enclosed, or otherwise by protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger.
NFPA 79 6.2 Protection against Direct Contact. Live parts operating at 50 volts rms or 60 volts dc or more shall be guarded against contact.