INSULATION OF LIVE PARTS. All equipment required to be insulated in order to obviate danger to life or property, shall be thoroughly insulated by Contractor at its expense. Lamps, wires, conductors, and other movable equipment shall be placed in such locations and in such manner as will prevent unauthorized persons from handling or tampering with them. Ladders, guards, etc. shall not be left attached to or resting against lampposts or poles.