California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 7 - General Industry Safety Orders
Group 13 - Cranes and Other Hoisting Equipment
Article 98 - Operating Rules
Section 5003.3 - Power Line Safety (All Voltages) - Equipment Operations Closer than the Table a Zone

(a) Equipment operations in which any part of the equipment, load line, or load (including rigging and lifting accessories) is closer than the minimum approach distance under Table A of Section 5003.1 to an energized power line is prohibited except as permitted by the High-Voltage Electrical Safety Orders.

(b) Except where overhead electrical distribution and transmission lines have been de-energized and visibly grounded, the operation, erection, or handling of tools, machinery, apparatus, supplies, or materials, or any part thereof, over power lines is prohibited.

EXCEPTION TO SUBSECTION (b): Tower cranes equipped with limit switches or other systems that automatically control slew, trolley and boom travel to prevent moving any portion of the load or load line within a horizontal proximity to power lines closer than the minimum clearances set forth in Table A of Section 5003.1.