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 20 - Interrupting and Isolating Devices
Section 2845 - Power Fuses
Current through Register 2024 Notice Reg. No. 38, September 20, 2024
(a) Use. Where fuses are used to protect conductors and equipment, a fuse shall be placed in each ungrounded conductor.
(b) Vented Power Fuses. Power fuses of the vented type shall not be used indoors, underground or in metal enclosures unless identified for the use.
(c) Interrupting Rating. The interrupting rating of power fuses shall equal or exceed the maximum fault current the fuse will be required to interrupt, including contributions from all connected sources of energy.
(d) Voltage Rating. The maximum voltage rating of power fuses shall equal or exceed the maximum circuit voltage. Fuses having a minimum recommended operating voltage shall not be applied below this voltage.
(e) Installation. Fuses shall be installed in suitable metal enclosures. Exception: Fuses shall be permitted to be installed without metal enclosures in substations, vaults, or outdoor locations.
(f) Structure Mounted Indoor or Outdoor. The height of fuse mountings on structures shall provide safe clearance between lowest energized part (open or closed position) and standing surface. For mounting heights, see Article 35.
(g) Disconnecting Means. A suitable means shall be installed to isolate each fuse from all sources of potential. Provision for installation and removal of the fuse by suitable live line tools meets this requirement.
(h) Identification of Fuse Mountings and Fuse Units. The fuse mountings and fuse units shall be permanently and legibly identified to include the following information: manufacturer's type or designation, continuous current rating, interrupting current rating, and maximum voltage rating.
(i) Clear Workspace. Space shall be provided for fuse handling in accordance with Article 35.
(j) Door Interlock. Means shall be provided to prevent access to fuses installed in metal enclosures until all sources of energy are disconnected.
(k) Enclosed Fuse Types. Fuses installed in metal enclosures shall be of the non-vented or controlled-vented type. Adequate volume or other means shall be provided to prevent the operation of fuses from causing dangerous pressures in enclosures.
(l) Fused cutouts installed in buildings or transformer vaults shall be of a type approved for the purpose. They shall be readily accessible for fuse replacement.
1. New subsection (k) filed 2-1-83; effective thirtieth day thereafter (Register 83, No. 6).
2. Editorial correction including renumbering of former article 72 to article 23 filed 11-2-83 (Register 83, No. 45).
3. Amendment filed 12-10-87; operative 1-9-88 (Register 88, No. 1.)
4. Change without regulatory affect redesignating subsections (b) through (k) as (c) through (l) filed pursuant to section 100, Title 1, California Code of Regulations (Register 91, No. 7).
5. Removal of article 23 heading and amendment of subsection (a)(1)(B) 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).
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
