Section 408.40655. Design requirements for other types of electrical protective equipment.

(1) The following requirements apply to the design and manufacture of electrical protective equipment that is not covered by R 408.40650:

(2)    Insulating equipment used for the protection of employees shall be capable of withstanding, without failure, the voltages that may be imposed upon it.

Note 1 to subrule (2): These voltages include transient over-voltages, such as switching surges, as well as nominal line voltage. See Construction Safety Standard Part 16 “Power Transmission and Distribution,” Appendix B, as referenced in R 408.40603, for a discussion of transient over-voltages on electric power transmission and distribution systems.

Note 2 to subrule (2): See IEEE 516 “Guide for Maintenance Methods on Energized Power Lines,” 2009 edition, as adopted in R 408.40603, for methods of determining the

magnitude of transient over-voltages on an electrical system and for a discussion comparing the ability of insulation equipment to withstand a transient overvoltage based on its ability to withstand alternating current voltage testing.

(3)   Equipment current shall comply with both of the following:

(a)   Protective equipment used for the primary insulation of employees from energized circuit parts shall be capable of passing a current test when subjected to the highest nominal voltage on which the equipment is to be used.

(b)   When insulating equipment is tested pursuant to these rules, the equipment current shall not exceed 1 microampere per kilovolt of phase-to-phase applied voltage.

Note 1 to subrule (3): This rule shall apply to equipment that provides primary insulation of employees from energized parts. It does not apply to equipment used for secondary insulation or equipment used for brush contact only.

Note 2 to subrule (3): For alternating current excitation, this current shall consist of the following components:

(i)    Capacitive current because of the dielectric properties of the insulating material itself.

(ii)   Conduction current through the volume of the insulating equipment.

(iii)   Leakage current along the surface of the tool or equipment.

The conduction current shall be normally negligible. For clean, dry insulating equipment, the leakage current shall be small, and the capacitive current shall be predominate.

Note 3 to (3): Plastic guard equipment is considered to conform to the performance requirements of this rule, if it meets, and is used in accordance with ASTM F-712 “Standard Test Methods and Specifications for Electrically Insulating Plastic Guard Equipment for Protection of Workers,” 2006 edition with 2011 supplement, as adopted in R 408.40603.

History: 2015 AACS.