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Safety
01.4IB.50023A
Ch 2 Safety
A. S
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The information in Section A is quoted from
NFPA 70E 2018 - Article 120, 120.5 Establishing an
Electrically Safe Work Condition.
120.5 Process or Establishing and Verifying an
Electrically Safe Work Condition.
Establishing
and verifying an electrically safe condition shall
include all of the following steps, which shall be
performed in the order presented, if feasible:
1. Determine all possible sources of electrical
supply to the specific equipment. Check
applicable up-to-date drawings, diagrams,
and identification tags.
2. After properly interrupting the load current,
open the disconnecting device(s) for each
source.
3. Wherever possible, visually verify that all
blades of the disconnecting devices are
fully open or that drawout-type circuit
breakers are withdrawn to the fully
disconnected position.
4. Release stored electrical energy.
5. Release or block stored mechanical energy.
6. Apply lockout/tagout devices in accordance
with a documented and established
procedure.
7. Use an adequately rated portable test
instrument to test each phase conductor or
circuit part to verify it is de-energized. Test
each phase conductor or circuit part both
phase-to-phase and phase-to-ground.
Before and after each test, determine
that the test instrument is operating
satisfactorily through verification on any
known voltage source.
N
Exception No. 1: An adequately rated
permanently mounted test device shall be
permitted to be used to verify the absence of
voltage of the conductors or circuit parts at
the work location, provided it meets the all
following requirements: (1) It is permanently
mounted and installed in accordance with
the manufacturer’s instructions and tests
the conductors and circuit parts at the point
of work; (2) It is listed and labeled for the
purpose of verifying the absence of voltage;
(3) It tests each phase conductor or circuit
part both phase-to-phase and phase-to-
ground; (4) The test device is verified as
operating satisfactorily on any known voltage
source before and after verifying the absence
of voltage.
N
Exception No. 2: On electrical systems over
1000 volts, noncontact test instruments shall
be permitted to be used to test each phase
conductor.
Informational Note No. 1: See UL 61010-1
,
Safety Requirements for Electrical Equipment
for Measurement, Control, and Laboratory
Use, Part 1: General Requirements,
for
rating, overvoltage category, and design
requirements for voltage measurement
and test instruments intended for use on
electrical system 1000 volts and below.
N
Informational Note No. 2: For additional
information on rating and design
requirements for voltage detectors, refer
to IEC 61243-1,
Live Working - Voltage
Detectors - Part 1: Capacitive type to be used
for voltages exceeding 1kV a.c.,
or IEC 61243-
2,
Live Working - Voltage Detectors - Part 2:
Resistive type to be used for voltages of 1kV
to 36kV a.c., or
IEC 61243-3,
Live Working -
Voltage Detectors - Part 3: Two-pole voltage
type.
