General Order 128

Section III

Requirements for Supply Systems

35.2    Guarding Live Parts

A.    Live parts shall be enclosed, isolated, guarded, or insulated to prevent accidental contact. (See Rules 21.2, 22.0, and 21.6 for definitions of "enclosed", "isolated", and "guarded".)

B.    In locations accessible only to qualified electrical workers, exposed conductive parts energized above 750 volts shall be located or enclosed so as to prevent accidental contact by persons or objects.

EXCEPTION:    When the measures set forth in 35.2-B are not practicable, such live parts shall be temporarily protected by suitable covers or barriers during construction, maintenance or operation activities.