Subchapter 5. Electrical Safety Orders
Group 2. High-Voltage Electrical Safety Orders
ARTICLE 20. INTERRUPTING AND ISOLATING DEVICES
(a) Installation. The cutouts shall be so located that they may be readily and safely operated and refused, and so that the exhaust of the fuses will not endanger persons. Distribution cutouts shall not be used indoors, underground, or in metal enclosures.
(b) Interrupting Rating. The interrupting rating of distribution cutouts shall equal or exceed the maximum fault current which can occur at the fuse location. The available fault current at the fuse location shall include contributions from all connected sources of energy, such as the other lines, generators, large motors, etc.
(c) Voltage Rating. The maximum voltage rating of cutouts shall equal or exceed the maximum circuit voltage.
(d) Operation. Where fused cutouts are not suitable to interrupt the circuit manually while carrying full load, an approved means shall be installed to interrupt the entire load.
Unless the fused cutouts are interlocked with the switch to prevent opening of the cutouts under load, a conspicuous sign shall be placed at such cutouts reading, “Warning-Do Not Operate Under Load.”
(e) Identification. Distribution cutouts and fuse links shall have a permanent and legible nameplate or identification including the following information:
(1) Cutout Body, Door, or Fuse Tube. Manufacturer's type or designation, continuous current rating, maximum voltage rating, interrupting rating.
(2) Fuse Links. Continuous current rating, type identification following the continuous current rating.
(f) Structure Mounted Outdoors. The height of cutouts mounted outdoors on structures shall provide safe clearance between lowest energized parts (open or closed position) and standing surfaces. For mounting heights, see Articles 19 and 35.
(g) Clear Workspace. Space shall be provided for fuse handling in accordance with Article 35.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. Editorial correction including renumbering of former Article 73 to Article 24 filed 11-2-83 (Register 83, No. 45).
2. Amendment of subsections (a)-(d) and (f) filed 12-10-87; operative 1-9-88 (Register 88, No. 1).
3. Removal of article 24 heading and amendment of section 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).