California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 5 - Electrical Safety Orders
Group 2 - High-Voltage Electrical Safety Orders
Article 17 - Enclosures for Electrical Installations
Section 2812.1 - Fenced or Walled Enclosures

(a) The height of enclosures shall be 8 feet minimum, or floor to ceiling if the ceiling is less than 8 feet.

EXCEPTIONS:

(b) The enclosure shall be so constructed that it cannot be readily climbed.

(c) The size and location of openings in fences or similar enclosures shall be such that persons are not liable to come into accidental contact with energized parts, or to bring conducting objects into contact with them.

(d) The gate or door in the enclosure shall have minimum dimensions of 2 feet 6 inches wide and 6 feet 6 inches high, and shall be readily operable. No reduction in enclosure height at the door or gate is permitted.

(e) Metal gates or doors shall be grounded or bonded to a grounded metal enclosure. Metal fences shall be grounded as required by Article 6.

(f) If buildings form a part of an enclosure, there shall be no unguarded doors or windows which permit unintentional access to the enclosure. Where the enclosure is adjacent to and below stairways, fire escapes, balconies, or windows, suitable guards shall be installed to prevent persons from making accidental contact with energized parts.

(g) Where oil-filled apparatus is installed within an enclosure adjacent to combustible material or combustible buildings, provision shall be made to confine within the enclosure the largest amount of oil contained in a single piece of apparatus.

(h) Pressure relief devices of oil-filled apparatus shall be designed and located to minimize the hazard to persons from escaping oil.

(i) Materials other than those required for operation of the facilities shall not be stored in vaults or fenced enclosures.