(a) Application. This section provides for
safe work practices for high-voltage and high-power testing performed in
laboratories, shops, and substations, and in the field and on electric
transmission and distribution lines and equipment. It applies only to testing
involving interim measurements using high voltage, high power, or combinations
of high voltage and high power, and not to testing involving continuous
measurements as in routine metering, relaying, and normal line work.
EXCEPTION to subsection (a): For the purposes of this
section, routine inspection and maintenance measurements made by qualified
employees shall be considered to be routine line work not included in the scope
of this section, provided that the hazards related to the use of intrinsic
high-voltage or high-power sources require only the normal precautions
associated with routine work specified in the other sections of the
High-Voltage Electrical Safety Orders. Two typical examples of such excluded
test work procedures are "phasing-out" testing and testing for a "no-voltage"
condition.
(b) General
Requirements.
(1) Safe work practices. The
employer shall establish and enforce work practices for the protection of each
worker from the hazards of high-voltage or high-power testing at all test
areas, temporary and permanent. Such work practices shall include, at a
minimum, test area safeguarding, grounding, the safe use of measuring and
control circuits, and a means providing for periodic safety checks of field
test areas.
(2) Training. The
employer shall ensure that each employee, upon initial assignment to the test
area, receives training in safe work practices, with retraining provided in
accordance with Section
2940 of these Orders and Section
3203 of the General Industry Safety
Orders.
(c) Safeguarding
of Test Areas.
(1) The employer shall provide
safeguarding within test areas to control access to test equipment or to
apparatus under test that could become energized as part of the testing by
either direct or inductive coupling and to prevent accidental employee contact
with energized parts.
(2) Permanent
test areas. The employer shall guard test areas with walls, fences, or other
barriers to keep employees out of test areas.
(3) Temporary test areas. In field testing,
or at a temporary test site not guarded by permanent fences and gates, the
employer shall ensure the use of one of the following means to prevent
employees without authorization from entering:
(A) Distinctively colored safety tape
supported approximately waist high with safety signs attached to it,
(B) A barrier or barricade that limits access
to the test area to a degree equivalent, physically and visually, to the
barricade specified in subsection (c)(3)(A) of this section, or
(C) One or more test observers stationed so
that they can monitor the entire area.
(4) Removal of safeguards. The employer shall
ensure the removal of the safeguards required by subsection (c)(3) of this
section when employees no longer need the protection afforded by the
safeguards.
(d) Grounding
Practices.
(1) Establish and implement
practices. The employer shall establish and implement safe grounding practices
for the test facility.
(A) The employer shall
maintain at ground potential all conductive parts accessible to the test
operator while the equipment is operating at high voltage.
(B) Wherever ungrounded terminals of test
equipment or apparatus under test may be present, they shall be treated as
energized until tests demonstrate that they are
deenergized.
(2)
Installation of grounds. The employer shall ensure either that visible grounds
are applied automatically, or that employees using properly insulated tools
manually apply visible grounds, to the high-voltage circuits after they are
deenergized and before any employee performs work on the circuit or on the item
or apparatus under test. Common ground connections shall be solidly connected
to the test equipment and the apparatus under test.
(3) Isolated ground return. In high-power
testing, the employer shall provide an isolated ground-return conductor system
designed to prevent the intentional passage of current, with its attendant
voltage rise, from occurring in the ground grid or in the earth. However, the
employer need not provide an isolated ground-return conductor if the employer
can demonstrate that both of the following conditions exist:
(A) The employer cannot provide an isolated
ground-return conductor due to the distance of the test site from the electric
energy source, and
(B) The employer
protects employees from any hazardous step and touch potentials that may
develop during the test.
NOTE to subsection (d)(3)(B): See Appendix E for
information on measures that employers can take to protect employees from
hazardous step and touch potentials.
(4) Equipment grounding conductors. For tests
in which using the equipment grounding conductor in the equipment power cord to
ground the test equipment would result in greater hazards to test personnel or
prevent the taking of satisfactory measurements, the employer may use a ground
clearly indicated in the test set-up if the employer can demonstrate that this
ground affords protection for employees equivalent to the protection afforded
by an equipment grounding conductor in the power supply cord.
(5) Grounding after tests. The employer shall
ensure that, when any employee enters the test area after equipment is
deenergized, a ground is placed on the high-voltage terminal and any other
exposed terminals.
(A) Before any employee
applies a direct ground, the employer shall discharge high capacitance
equipment through a resistor rated for the available energy.
(B) A direct ground shall be applied to the
exposed terminals after the stored energy drops to a level at which it is safe
to do so.
(6) Grounding
test vehicles. If the employer uses a test trailer or test vehicle in field
testing, its chassis shall be grounded. The employer shall protect each
employee against hazardous touch potentials with respect to the vehicle,
instrument panels, and other conductive parts accessible to employees with
bonding, insulation, or isolation.
(e) Control and Measuring Circuits.
(1) Control wiring. The employer shall not
run control wiring, meter connections, test leads, or cables from a test area
unless contained in a grounded metallic sheath and terminated in a grounded
metallic enclosure or unless the employer takes other precautions that it can
demonstrate will provide employees with equivalent safety.
(2) Instruments. The employer shall isolate
meters and other instruments with accessible terminals or parts from test
personnel to protect against hazards that could arise should such terminals and
parts become energized during testing. If the employer provides this isolation
by locating test equipment in metal compartments with viewing windows, the
employer shall provide interlocks to interrupt the power supply when someone
opens the compartment cover.
(3)
Routing of temporary wires. The employer shall protect temporary wiring and its
connections against damage, accidental interruptions, and other hazards. To the
maximum extent possible, the employer shall keep signal, control, ground, and
power cables separate from each other.
(4) Test observer. If any employee will be
present in the test area during testing, a test observer shall be present. The
test observer shall be capable of implementing the immediate deenergizing of
test circuits for safety purposes.
(f) Safety Check.
(1) Before each test. Safety practices
governing employee work at temporary or field test areas shall provide, at the
beginning of each series of tests, for a routine safety check of such test
areas.
(2) Conditions to be
checked. The test operator in charge shall conduct these routine safety checks
before each series of tests and shall verify at least the following conditions:
(A) Barriers and safeguards are in workable
condition and placed properly to isolate hazardous areas;
(B) System test status signals, if used, are
in operable condition;
(C) Clearly
marked test-power disconnects are readily available in an emergency;
(D) Ground connections are clearly
identifiable;
(E) Personal
protective equipment is provided and used as required by Article 10 of the GISO
and by Section
2940.06, Section
2940.11, and this section;
and
(F) Proper separation between
signal, ground, and power cables.