This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 5. Electrical Safety Orders
Group 2. High-Voltage Electrical Safety Orders
Article 37. Provisions for Preventing Accidents Due to Proximity to Overhead Lines (Formerly Article 86)

Return to index
New query
§2946. Provisions for Preventing Accidents Due to Proximity to Overhead Lines.
Tailgate/Toolbox Topics: High Voltage Overhead Lines

(a) General. No person, firm, or corporation, or agent of same, shall require or permit any employee to perform any function in proximity to energized high-voltage lines; to enter upon any land, building, or other premises and there engage in any excavation, demolition, construction, repair, or other operation; or to erect, install, operate, or store in or upon such premises any tools, machinery, equipment, materials, or structures (including scaffolding, house moving, well drilling, pile driving, or hoisting equipment) unless and until danger from accidental contact with said high-voltage lines has been effectively guarded against.

(b) Clearances or Safeguards Required. Except where overhead electrical distribution and transmission lines have been de-energized and visibly grounded, the following provisions shall be met:

 (1) Over Lines. The operation, erection, or handling of tools, machinery, apparatus, supplies, or materials, or any part thereof, over energized overhead high-voltage lines shall be prohibited. 

 Exception: 1: Aircraft over energized overhead high-voltage lines operating in conformance with: 

 (A) Applicable regulations administered by the Federal Aviation Administration, and/or 

 (B) Helicopter Operations, Article 35, Construction Safety Orders, California Administrative Code, Title 8. 

 Exception: 2: Tower cranes (Hammerhead) installed not closer than the minimum clearances set forth in Table 2, whereon the trolley or boom travel is controlled by limit switches which will prevent carrying a load over energized overhead high-voltage lines or within a horizontal distance closer than the minimum clearances set forth in Table 2. 

 (2) The operation, erection, handling, or transportation of tools, machinery, materials, structures, scaffolds, or the moving of any house or other building, or any other activity where any parts of the above or any part of an employee's body will come closer than the minimum clearances from energized overhead lines as set forth in Table 1 shall be prohibited. 

 Exception: Amusement rides or attractions shall not be located under or within 15 ft. (4.57 m) horizontally of conductors operating in excess of 600 volts. 

 Operation of boom-type equipment shall conform to the minimum clearances set forth in Table 2, except in transit where the boom is lowered and there is no load attached, in which case the distances specified in Table 1 shall apply. 


 General Clearances Required from Energized Overhead High-Voltage Conductors 

          Nominal voltage      Minimum Required
         (Phase to Phase)      Clearance (Feet)
      600........   50,000     6               
over  50,000.....   345,000    10              
over  345,000....   750,000    16              
over  750,000....   1,000,000  20              
 (3) Boom-type lifting or hoisting equipment. The erection, operation or dismantling of any boom-type lifting or hoisting equipment, or any part thereof, closer than the minimum clearances from energized overhead high-voltage lines set forth in Table 2 shall be prohibited. 

 (4) Storage. The storage of tools, machinery, equipment, supplies, materials, or apparatus under, by, or near energized overhead high-voltage lines is hereby expressly prohibited if at any time during such handling or other manipulation it is possible to bring such tools, machinery, equipment, supplies, materials, or apparatus, or any part thereof, closer than the minimum clearances from such lines as set forth in Table 1. 

(c) The specified clearance shall not be reduced by movement due to any strains impressed (by attachments or otherwise) upon the structures supporting the overhead high-voltage line or upon any equipment, fixtures, or attachments thereon.

(d) Any overhead conductor shall be considered to be energized unless and until the person owning or operating such line verifies that the line is not energized, and the line is visibly grounded at the work site.


Boom-type lifting or hoisting equipment clearances required from energized
overhead high-voltage lines.

          Nominal voltage      Minimum Required
         (Phase to Phase)      Clearance (Feet)
      600........   50,000     10              
over  50,000.....   75,000     11              
over  75,000.....   125,000    13              
over  125,000....   175,000    15              
over  175,000....   250,000    17              
over  250,000....   370,000    21              
over  370,000....   550,000    27              
over  550,000....   1,000,000  42              
<General Materials (GM) - References, Annotations, or Tables>

    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  

1. Amendment of subsections (b), (c), repealer of subsections (d), (e) and new
subsection (d) filed 8-9-79; effective thirtieth day thereafter (Register 79, 
No. 32).

2. Editorial correction renumbering former Article 86 to Article 37 filed 11-2-
83 (Register 83, No. 45).

3. Amendment filed 12-10-87; operative 1-9-88 (Register 88, No. 1).

4. Amendment of subsection (b)(2) filed 4-1-2009; operative 4-1-2009. Submitted
to OAL for printing only pursuant to Labor Code section 142.3 (Register
2009, No. 14).

Go BackGo Back to Article 37 Table of Contents