(a) Application. This section applies to
grounding of transmission, and distribution lines and equipment for the purpose
of protecting employees. Subsection (f) of this section also applies to
protective grounding of other equipment as required elsewhere in this
Article.
(b) General. For any
employee to work transmission and distribution lines or equipment as
deenergized, the employer shall ensure that the lines or equipment are
deenergized under the provisions of Section
2940.14 and shall ensure proper
grounding of the lines or equipment as specified in subsections (c) through (i)
of this section. However, if the employer can demonstrate that installation of
a ground is impracticable or that the conditions resulting from the
installation of a ground would present greater hazards to employees than
working without grounds, the lines and equipment may be treated as deenergized
provided that the employer establishes that all of the following conditions
apply:
(1) The employer ensures that the
lines and equipment are deenergized under the provisions of Section
2940.14.
(2) There is no possibility of contact with
another energized source.
(3) The
hazard of induced voltage is not present.
(c) Testing. Tests shall be conducted to
insure that conductors or equipment have been deenergized before employees
install any ground on lines or equipment.
(d) Guards or barriers shall be installed as
necessary to prevent contact with another exposed energized conductor or
equipment.
(e) Equipotential Zone.
Temporary protective grounds shall be placed at such locations and arranged in
such a manner that the employer can demonstrate will prevent each employee from
being exposed to hazardous differences in electric potential.
NOTE to subsection (e): Appendix E to this Article
contains guidelines for establishing the equipotential zone required by this
subsection. The Division of Occupational Safety and Health will deem grounding
practices meeting these guidelines as complying with subsection (e) of this
section.
(f) Protective
Grounding Equipment.
(1) Conductor(s) or
equipment to be grounded shall be clearly identified and isolated from all
sources of voltage.
(2) Protective
grounding equipment shall be capable of conducting the maximum anticipated
fault current.
(3) Grounding
devices shall have a minimum conductance of No. 2 AWG copper.
(4) Protective grounds shall have an
impedance low enough so that they do not delay the operation of protective
devices in case of accidental energizing of the lines or equipment.
(5) There shall be a minimum of one ground on
the conductors or equipment being worked on:
(A) between the place where the work is being
done and each possible source of supply,
(B) at the work location, or
(C) as close as practicable to the source of
supply.
(6) One of the
grounding devices shall be visible to at least one member of the crew unless
one of the grounding devices is accessible only to authorized persons.
NOTE to subsection (f): Guidelines for protective
grounding equipment are contained in American Society for Testing and Materials
Standard Specifications for Temporary Grounding Systems to be Used on
De-Energized Electric Power Lines and Equipment, ASTM F 855-09. Guidelines for
selecting and installing protective grounding equipment are contained in The
Institute of Electrical Engineers Guide for Protective Grounding of Power
Lines, IEEE Std 1048-2003.
(g) Connecting and Removing Grounds.
(1) Order of connection. The employer shall
ensure that, when an employee attaches a ground to a line or to equipment, the
employee attaches the ground-end connection first and then attaches the other
end by means of a live-line tool.
(2) Order of removal. The employer shall
ensure that, when an employee removes a ground, the employee removes the
grounding device from the line or equipment using a live-line tool before he or
she removes the ground-end connection.
(h) Additional Precautions. The employer
shall ensure that, when an employee performs work on a cable at a location
remote from the cable terminal, the cable is not grounded at the cable terminal
if there is a possibility of hazardous transfer of potential should a fault
occur.
(i) Removal of Grounds for
Test. The employer may permit employees to remove grounds temporarily during
tests. During the test procedure, the employer shall ensure that each employee
uses insulating equipment, shall isolate each employee from any hazards
involved, and shall implement any additional measures necessary to protect each
exposed employee in case the previously grounded lines and equipment become
energized.