2.0 GENERAL REQUIREMENTS
This section deals with the reliability
and effective maintenance of electrical systems that can be achieved in part by careful planning and proper design. The training of personnel
in safety-related work practices that pertain to their respective job assignments is outlined.
2.1 ELECTRICAL MAINTENANCE OR REPAIRS
Only qualified persons shall perform electrical repairs. Once a problem is discovered while
troubleshooting or maintaining electrical equipment,
any further work on this component or
system must be suspended until the associated corrective actions are processed through a
system. It is dangerous for an unqualified worker to attempt electrical repair.
Before any electrical maintenance or troubleshooting is performed,
sources of electrical energy
shall be deenergized, except where it is necessary for troubleshooting, testing, or areas that are
to deenergize. All energy sources shall be brought to a safe state. For example,
capacitors shall be discharged and high capacitance elements
shall be short-circuited and
2.1.1 WORK ON ENERGIZED/DEENERGIZED ELECTRICAL EQUIPMENT
The first consideration for working
on any electrical system is to have the circuit positively
deenergized. All circuits and equipment must be considered energized until opened,
and/or locked according to an approved procedure and should be proven deenergized by
testing with an approved testing device known
to be in proper working order. NFPA 70E refers
to this as an electrically safe work condition and defines it as “a state in which the conductor
circuit part to be worked on or near has been disconnected from energized parts, locked/tagged
in accordance with established standards,
tested to ensure the absence of voltage, and
grounded if determined necessary.” The electrical hazard controls identified in NFPA 70E are
intended to protect a person from arc flash and shock hazards. Due to the explosive effects of
some arc events, physical trauma injuries
could occur. The personal protective equipment
(PPE) requirement identified in NFPA 70E is intended to protect against physical trauma other
than exposure to the thermal effects of an arc flash.
2.1.2 CONSIDERATIONS FOR WORKING ON ENERGIZED SYSTEMS AND
employees performing such tasks as electrical repairs, modifications, and tests on
energized electrical systems, parts, and equipment need
to comply with the following:
1. Parts to which an employee might be exposed shall be put into an electrically safe work
before the employee works on or near them, unless the employer can
demonstrate that deenergizing introduces additional or increased hazards
or is infeasible
due to equipment design or operational limitations.
2. Personnel shall not work on energized circuits unless they
are qualified to do so, or, for
training purposes, unless they work under the direct supervision of a qualified person.
protection in the form of insulated tools and insulated protective equipment,
such as gloves, blankets, sleeves, mats, etc., shall be used
while working on energized
circuits. (See NFPA 70E)
4. Other work, independent of voltage, that presents a significant shock, arc flash, or arc
blast hazard to employees.
Note: The discussion in #4 above assumes the system voltage is less than the maximum use
voltage of the ASTM class of rubber goods used.
2.1.3. SAFETY WATCH RESPONSIBILITIES AND QUALIFICATIONS
The responsibilities and qualifications of personnel for sites that require the
use of a safety
watch are as follows:
1. Trained in cardiopulmonary resuscitation (CPR);
2. Possessing a thorough knowledge
of the locations of emergency-shutdown push buttons
and power disconnects in their operations;
3. Possessing a thorough knowledge
of the specific working procedures to be followed and
the work to be done;
4. Specific responsibilities include monitoring the work
area for unsafe conditions or work
practices and taking necessary action to ensure abatement of the unsafe condition or
deenergizing equipment and alerting emergency-rescue personnel as
conditions warrant, maintaining visual and audible contact with personnel
work, and removal of injured personnel, if possible; and
5. The safety watch should have no other duties that preclude
observing and rendering aid
2.2 BASIC SAFEGUARDS
To protect employees from some of the electrical hazards at industrial
sites, Federal regulations
limit the performance of electrical work to qualified and competent personnel. Specifically, the
that only a qualified person or someone working under the direct supervision of a
qualified person may perform any repair, installation,
or testing of electrical equipment. See
Section 2.8 and the definitions of "Qualified Employee" or "Qualified Person" in Appendix B.
of the best ways to prevent electrical accidents at industrial sites is to be aware of electrical
dangers in the workplace. Once hazards
have been identified, they must be pointed out and
proper steps taken by a qualified person.
The following, where used, will improve
the safety of the workplace:
1. Maintain good housekeeping and cleanliness.
2. Identify and control potential hazards.
4. Resist pressure to "hurry up."
5. Plan and analyze for safety in each step of a project.
6. Document work.
7. Use properly rated test equipment and verify its condition and operation before and after
and practice applicable emergency procedures.
9. Become qualified in CPR and first aid and maintain current certifications.
10. Wear appropriate
11. Refer to system drawings and perform system walk-downs.
12. Electrical equipment should be maintained in accordance with the
13. Ensure that work is adequately planned through an approved work control process.
Management is responsible to provide a workplace that is free from recognized hazards that
might cause injury, illness, or death and to comply
with the specific safety and health standards
issued by Federal, state, and local authorities, particularly OSHA. Managers expect their
employees to comply with these regulations as well as the DOE requirements formulated for the
health and safety of employees. Prevention
of injury and illness requires the efforts of all and is
a goal well worth achieving.
2.3.1 MANAGEMENT RESPONSIBILITIES
safety and protection of employees, managers have the following responsibilities:
1. Ensure that employees are provided a workplace that
is free from recognized hazards.
2. Ensure that employees performing electrical work are trained and qualified (see Section
Ensure that approved, maintained, and tested personal protective equipment and clothing is
provided, available, and used properly.
Establish, implement, and maintain procedures and practices that will ensure safe conduct
of electrical work.
5. Keep and maintain records
2.3.2 EMPLOYEE RESPONSIBILITIES
Employees are responsible to comply with occupational safety and health regulations and
standards that apply to their own actions and conduct, including immediate reporting to
management of unsafe and unhealthful conditions.
All modifications to existing and new facilities and projects should be subject to inspection by
AHJ or authorized designee to verify compliance with the codes and standards in effect on
the date that the work was approved by a final
design review. If the installation involves a
hazard to life, equipment, or property, current standards and codes should be used to mitigate
According to OSHA, all major replacements, modifications, repairs, or rehabilitation performed
after March 15, 1972, on
electrical systems and equipment installed before March 15,1972, are
required to comply with all the requirements of 29 CFR 1910.302 to 1910.308.
major replacements, modifications, or rehabilitation to be work similar to that involved when a
new building or facility
is built, a new addition is built, or an entire floor is renovated.
2.5 APPROVAL OF ELECTRICAL EQUIPMENT
All electrical equipment,
components, and conductors shall be approved for their intended uses.
If any electrical system component is of a kind that any Nationally
Laboratory (NRTL) accepts, certifies, lists, or labels, then only NRTL accepted, certified, listed,
or labeled components
can be used. A nonlisted, nonlabeled, noncertified component may be
used if it is of a kind that no NRTL covers, and then it shall be tested
or inspected by the local
authority responsible for enforcing the Code. For example, this would apply to custom-made
equipment. The custom-made
equipment should be built in accordance with a design approved
by the AHJ.
See 29 CFR 1910.399 for definitions relating to OSHA requirements
for accepting electrical
equipment and wiring methods that are not approved by an NRTL.
2.6 CODES, STANDARDS, AND REGULATIONS
who perform electrical or electronic work, where applicable, shall comply with relevant
DOE Orders that may identify the following codes
1. Standards published by the National Fire Protection Association (NFPA)
2. National Electrical Safety Code, ANSI
3. All relevant state and local requirements.
4. Components or installations in aircraft, watercraft, and railroads are exempt from
above approval requirements.
The standards and performance specifications from the following organizations are
and should be observed when applicable:
1. Institute of Electrical and Electronics Engineers (IEEE)
2. National Electrical Manufacturers
3. American National Standards Institute (ANSI)
4. American Society for Testing and Materials (ASTM)
5. National Fire Protection Association (NFPA)
6. Underwriters Laboratory,
7. Factory Mutual Engineering Corporation (FMEC)
8. Other NRTLs recognized by OSHA on a limited basis.
Where no clear
applicable code or standard provides adequate guidance or when questions
regarding workmanship, judgment, or conflicting criteria arise,
personnel safety protection shall
be the primary consideration. Therefore, where there are conflicts between the mandatory
of the above codes, standards, and regulations, the requirements that address the
particular hazard and provide the greater safety shall
2.7 GROUND FAULT CIRCUIT INTERRUPTERS (GFCIs) AND ARC
FAULT CIRCUIT INTERRUPTERS (AFCIs)
There are two classes of GFCIs,
each with a distinct function. A Class A GFCI trips when the
current to ground has a value in the range of 4 through 6 milliamperes and is
used for personnel
protection. A Class A GFCI is suitable for use in branch circuits. A Class B GFCI (commonly
used as ground fault protection
for equipment) trips when the current to ground exceeds 20
milliamperes. A Class B GFCI is not suitable for employee protection.
circuit protection can be used in any location, circuit, or occupancy to provide
additional protection from line-to-ground shock hazards
because of the use of electric hand
tools. There are four types of GFCIs used in the industry:
1. Circuit breaker type
3. Portable type
4. Permanently mounted type
The condition of use determines the type of GFCI selected. For example, if an
maintenance person plugs an extension cord into a non-protected GFCI receptacle, the easiest
way to provide GFCI protection
is to utilize a portable-type GFCI.
2.7.1 HOW A GFCI WORKS
See Section 4.14 for ground-fault protection of equipment. GFCIs are devices
that sense when
current—even a small amount—passes to ground through any path other than the proper
conductor. When this condition exists,
the GFCI quickly opens the circuit, stopping all current
flow to the circuit and to a person receiving the ground-fault shock.
2-1 shows a typical circuit arrangement of a GFCI designed to protect personnel. The
incoming two-wire circuit is connected to a two-pole,
shunt-trip overload circuit breaker. The
load-side conductors pass through a differential coil onto the outgoing circuit. As long as the
Figure 2-1. GFCI-protected circuits are one way of providing protection of personnel
using electric hand
tools on construction sites or other locations.
current in both load wires is within specified tolerances, the circuit functions normally. If one of
the conductors comes in contact
with a grounded condition or passes through a person's body
to ground, an unbalanced current is established. This unbalanced current is picked
up by the
differential transformer, and a current is established through the sensing circuit to energize the
shunt trip of the overload
circuit breaker and quickly open the main circuit. A fuse or circuit
breaker cannot provide this kind of protection. The fuse or circuit
breaker will trip or open the
circuit only if a line-to-line or line-to-ground fault occurs that is greater than the circuit protection
Differential transformers continuously monitor circuits to ensure that all current that flows out to
motor or appliances
returns to the source via the circuit conductors. If any current leaks to a
fault, the sensing circuit opens the circuit breaker and stops
all current flow.
A GFCI will not protect the user from line-to-line or line-to-neutral contact hazards. For example, if
using a double-insulated drill with a metal chuck and drill bit protected by a GFCI
device drills into an energized conductor and contacts
the metal chuck or drill bit, the GFCI device
will not trip (unless it is the circuit the GFCI device is connected to) as it will not detect
The use of GFCIs in branch circuits for other than dwelling units is defined in the NEC 410.4.
Figure 2-1. GFCI-protected circuits are one way of providing protection of personnel
using electric hand tools on construction sites or other
Ground-fault protection for personnel shall be provided for temporary wiring installations utilized to
supply temporary power
to equipment used by personnel during construction, remodeling,
maintenance, repair, or demolition activities.
For temporary wiring
a) All 120-V, single-phase, 15-, 20-, and 30-A receptacle outlets that are or are not a part of
the permanent wiring
of the building or structure and that are in use by employees shall
have GFCI protection for personnel.
b) GFCI protection or an assured
equipment grounding program (See Section 8.2) for all other
receptacles shall be used to protect against electrical shocks and hazards.
Portable GFCIs shall be trip-tested according to the manufacturer’s instructions.
2.7.3 ARC FAULT CIRCUIT INTERRUPTERS (AFCIs)
Figure 2-2. There are three methods of providing GFCI protection for construction sites
One of the more promising techniques for improvement of performance of wiring systems with
respect to arc-generated fires and intermittent equipment operation is the possibility of using the
arc voltage and current signatures to
trip circuits by an AFCI. An AFCI is a device intended to
provide protection from the effects of arc faults by recognizing characteristics
unique to arcing
Figure 2-2. There are three methods of providing GFCI protection for construction sites.
and by functioning to de-energize the circuit when an arc fault is detected (NEC 210.12 and
550.25). AFCIs are evaluated to UL1699,
Safety Standard for Arc-Fault Circuit Interrupters,
using testing methods that create or simulate arcing conditions to determine the product’s
to detect and interrupt arcing faults.
Although NEC 210.12 requires that AFCI protection be provided on branch circuits that
outlets (receptacle, lighting, etc.) in dwelling unit bedrooms, there is no prohibition against
providing AFCI protection on other
circuits or location other than the bedrooms. For example,
aircraft wire systems utilize AFCIs for newer installation to trip the circuit
sensitive areas such as fuel storage areas.
2.8 TRAINING AND QUALIFICATIONS OF QUALIFIED WORKERS
workers shall perform work on electrical systems. It is dangerous for unqualified
personnel to attempt to do electrical work. There should
be an employee training program
implemented to qualify workers in the safety-related work practices that pertain to their
2.8.1 FORMAL TRAINING AND QUALIFICATIONS
Management should establish formal training and qualifications for qualified
workers before they
are permitted to perform electrical work. Refresher training is recommended at intervals not to
exceed three years
to provide an update on new regulations and electrical safety criteria.
The training shall be on-the-job and/or classroom type. The degree
of training provided shall be
determined by the risk to the employee. This training shall be documented. Qualified
employees shall be
trained and familiar with, but not be limited to, the following:
1. Safety-related work practices, including proper selection and use
of PPE, that pertain to
their respective job assignments.
2. Skills and techniques necessary to distinguish exposed live parts from other
3. Skills and techniques necessary to determine the nominal voltage of exposed live parts,
distances, and the corresponding voltages to which the qualified person will be
4. Procedures on how to perform their jobs safely
5. How to lockout/tagout energized electrical circuits and equipment safely.
Other types of training recommended for
electrical workers include the following:
a. National Electrical Code (NFPA 70) (2002)
b. National Electrical Safety Code (ANSI C2)
c. Use of personal protective grounds
d. Use of testing and measuring equipment
e. Work permit and work authorization procedures
f. Use and care of personal protective equipment
g. Proper clothing required
for arc flash or arc blast protection
h. First-aid and CPR refresher training is recommended at intervals not to exceed 3 years
for Electrical Safety in the Workplace (NFPA 70E) (2004)
29 CFR 1910.269(a) and 1910.332 also require training for persons other than
if their job assignments bring them close enough to exposed parts of electrical circuits
operating at 50 V or more to
ground for a hazard to exist.
2.8.2 TRAINING OF SAFETY PERSONNEL
Safety personnel designated to support electrical safety programs
should be knowledgeable
and trained at levels commensurate with their duties.
2.9 WORKING SPACE AROUND ELECTRICAL EQUIPMENT
space around electrical enclosures or equipment shall be adequate for conducting all
anticipated maintenance and operations safely, including
sufficient space to ensure safety of
personnel working during emergency conditions and workers rescuing injured personnel.
provide the dimensional clearance (discussed in the following subsections) for
personnel access to equipment likely to require examination,
adjustment, servicing, or
maintenance while energized. Such equipment include panel boards, switches, circuit breakers,
and controls on heating and air conditioning equipment.
These clearances shall be in accordance with NESC and NEC. These working clearances
not required if the equipment is not likely to require examination, adjustment, servicing, or
maintenance while energized. However,
sufficient access and working space is still required.
2.9.1 ELECTRICAL EQUIPMENT RATED AT 600 VOLTS OR LESS
NEC 110.26 states that
a minimum working space 30 in. wide shall be provided in front of
electrical equipment rated at 600 V or less. This provides room to avoid
body contact with
grounded parts while working with energized components of the equipment. The 30-in.-wide
space may be centered in front
of the equipment or can be offset. The depth of the working
space shall be clear to the floor. Where rear access is required to work on deenergized
minimum of 30 inches shall be provided. There shall be clearance in the work area to allow at
least a 90-degree opening of equipment
doors or hinged panels on the service equipment.
Working spaces may overlap. The depth of the working space shall be 3 ft, 3 1/2 ft, or 4
depending upon existing conditions. The conditions are as follows:
Condition 1: These are exposed live components on one side
of a space and ungrounded parts
on the other side.
Condition 2: The electrical equipment is mounted or set on one wall, and the wall
opposite side is grounded. If the qualified worker should accidentally contact the conductive wall
while touching live components, a circuit would be completed to ground and a fatal shock might
Condition 3: The
electrical equipment is mounted or set on one wall, and additional electrical
equipment is mounted or set on the opposite side of the room.
There are live components on
both sides of the room. The qualified worker might accidentally make contact with live
components and be
in series with a hot phase and the grounded metal of the electrical
equipment, which could produce a fatal shock.
See Figure 2-3 for
the clearance requirements in front of electrical equipment rated 600 V or
Figure 2-3. Minimum clearances in front of electrical
equipment (600 V or less).
NEC Table 110.26(A)(1)
2.9.2 ELECTRICAL EQUIPMENT RATED OVER 600 VOLTS
NEC 110.34 lists minimum clearances required for working spaces in front of high-voltage
electrical equipment such as switchboards, control panels, switches, circuit breakers,
switchgear, and motor controllers.
three conditions to apply:
1. Where there are exposed live components on one side of a space and no live or
ungrounded parts on the
2. Where there are exposed live components on one side and grounded parts on the other
such as concrete, brick, and tile walls
that are considered to be grounded parts.
3. Where there are exposed live components on both sides.
See Figure 2-4 for the clearance requirements
in front of electrical equipment rated at over 600
V. See NEC for clearance requirements in the rear of electrical equipment.
Figure 2-4. Minimum clearances in front of electrical equipment (over 600 V).
2.10 IDENTIFICATION OF DISCONNECTION MEANS
Switches in service panels, subpanels, or elsewhere shall be marked to show what loads
equipment are supplied.
2.10.1 DISCONNECTING MEANS
In according to NEC 110.22, all disconnecting means (disconnect switches
or circuit breakers)
shall be located for easy access and shall be clearly and permanently marked to show the
purposes of the disconnects,
unless located and arranged so that the purpose is evident.
Labeling should match and be traceable to appropriate drawings. This applies
to all existing
electrical systems and all new, modernized, expanded, or altered electrical systems.
Disconnecting means shall be capable
of being locked out where required.
2.10.2 PANELBOARD CIRCUIT DIRECTORIES
Panelboard circuit directories shall be provided and fully
and clearly filled out.
2.10.3 ENCLOSURE LABELING
Printed labeling or embossed identification plates affixed to enclosures shall comply
requirements that disconnects be legibly marked and that the marking shall be of sufficient
durability for the environment involved.
2.10.4 LOAD LABELING
As with the disconnecting device, the load should be labeled. For example, the motor, the
controller, and the
disconnecting device could have the same identification number.
2.10.5 SOURCE LABELING
The source supplying power to the disconnecting
means and load should be labeled as well.
This requirement allows the electrical worker to know the identification of the elements from the
source of power through the entire circuit. (See Figure 2-5.)
Figure 2-5. Switchgear, panel boards, motor control centers, etc., should identify the
loads and elements
which they supply.
2.11 WORK INSTRUCTIONS
Before work begins, the qualified worker should ensure that the job to be done is in compliance
pertaining to the electrical work.
2.11.1 SAFE WORK INSTRUCTIONS AND SUPERVISION
Electrical work should be performed according to
written safety procedures and approved
electrical safety manuals. Electrical work should be directed by a supervisor who is qualified by
training and experience in the applicable safety-related work practices.
Workers should report any electrical hazards to their immediate
supervisor. The supervisor
should take all corrective actions necessary to address an employee's concerns.
should be based on a thorough analysis of the job and its hazards. If the
same task is repeated, it may be performed under specific work
rules that are based on such
Figure 2-5. Switchgear, panel boards, motor control
centers, etc., should identify the
loads and elements which they supply.
• NEC section 430.102
• NEC section 430.83
• NEC section
2.11.2 WORK INSTRUCTIONS
If no specific instruction is available and the job is beyond the scope of written work rules, the
supervisor should issue instructions pertaining to the job to be performed. The instructions
should contain the essential safety rules for
the job and, when documented, should be signed
by the employee, a line supervisor, or safety representative.
2.11.3 WORK PLANNING
Electrical instructions may include, but not be limited to, the following:
1. Deenergizing circuits, if possible, and providing a means
to prevent reenergization
2. Grounding conductors and all possible conducting parts
3. Controlling associated generating
4. Testing of equipment to ensure safe conditions
5. Provision of rubber-insulated protective equipment rated for the highest
6. Qualified personnel (see 2.1.2 and 2.1.3)
7. PPE and protective clothing (e.g., hardhats, safety shoes, eye and face
insulated live-line tools, hot sticks, cotton or fire-resistant clothing, and arc protection)
8. Working on experimental equipment
2.12 ELECTRICAL PERSONAL PROTECTIVE EQUIPMENT
Qualified workers are responsible for avoiding and preventing accidents while performing
electrical work, repairs, or troubleshooting electrical equipment. Personnel shall wear or use
PPE and protective clothing that is appropriate
for safe performance of work. Qualified workers
need to use appropriate arc-fault PPE whenever they work near electrical equipment that could
create an arc flash hazard.
2.12.1 MANAGEMENT'S RESPONSIBILITIES
Managers shall ensure that appropriate PPE is provided and ensure
that employees using PPE
are trained in their proper use. Furthermore, managers shall ensure that employees use the
appropriate PPE for
their assigned task.
2.12.2 INSPECTING PPE
Employees shall visually inspect rubber-insulated PPE at the beginning of each workday
use and after any work performed that could damage the equipment. Such inspections shall
include a field air test of the gloves
used. Visual inspection shall be performed on hot sticks,
grounds, aerial lift equipment and booms, rope, ladders, insulated tools, etc.
does not successfully pass visual inspection shall not be used and shall be returned for repair
and testing or disposal.
2.12.3 CLEANING AND ELECTRICAL TESTING OF PPE
Rubber-insulated PPE issued for use shall receive periodic cleaning and electrical
accordance with the requirements of the appropriate ANSI/ASTM standards listed in the
References section of this handbook.
The intervals of retest for rubber goods issued for service
shall not be more than 6 months for gloves and 12 months for sleeves and blankets.
sleeves that have been electrically tested but not issued for service shall not be placed into
service unless they have been
electrically tested within the previous 12 months.
All testing methods, apparatus, and facilities shall meet the
applicable ANSI/ASTM Standard.
The method used and the results of such tests shall be documented and made available for
188.8.131.52 TESTING APPARATUS
Testing apparatus shall be operated and maintained by personnel trained for such work.
and procedures for calibrating testing apparatus are recommended to be
in accordance with ANSI C39.1.
184.108.40.206 RETESTED PPE
rubber-insulated PPE shall be identified to indicate the date of the latest test or date of
retest in accordance with the appropriate standard.
Manufacturer's recommendations shall be
followed on the type of paint or ink to be used.
2.12.4 LIVE-LINE TOOLS
shall be cleaned and inspected before use and receive a dielectric test whenever
their insulating value is suspect. A record of the testing
of live-line tools shall be maintained.
220.127.116.11 FIBERGLASS-HANDLED TOOLS
Fiberglass-handled tools shall be tested by the manufacturer
at 100 kV per ft of length. The in-service
test shall be 75 kV per ft.
18.104.22.168 WOODEN-HANDLED TOOLS
Wooden-handled tools shall
be tested by the manufacturer to 75 kV per ft of length. The in-service
test shall be 50 kV per ft.
2.12.5 MAXIMUM USAGE VOLTAGE
Maximum usage voltage phase-to-phase or phase-to-ground for insulating blankets, mats,
hose, sleeves, and gloves shall be as follows:
Class Voltage Label Color
00 500 Beige
0 1,000 Red
1 7,500 White
3 26,500 Green
4 36,000 Orange
2.12.6 MAXIMUM USAGE VOLTAGE FOR LIVE-LINE TOOLS
Maximum usage voltage per foot of length
and phase-to-phase or phase-to-ground for live-line
tools shall be as follows:
1. Tools with wooden handles 69 kV
2. Tools with
fiberglass handles 93 kV
2.12.7 RUBBER-INSULATED GLOVES
Whenever rubber-insulated protective gloves are required, approved protective
gloves shall also
be worn (See Appendix C) for those conditions where rubber-insulated protective gloves can be
used without protectors.
Electrical insulating and protective clothing and equipment should be stored lying flat,
undistorted, right-side out,
and unfolded, as appropriate, in protective containers. Blankets may
be stored rolled provided the inner diameter of the roll is at least
Rubber goods shall be stored in a location as cool, dark, and dry as possible. The location shall
be as free as practicable from
ozone, chemicals, oils, solvents, damaging vapors and fumes,
and away from electrical discharges and sunlight. Rubber gloves should be stored
a bag, box, or container designed for rubber glove storage. Rubber gloves may be kept inside of
2.12.9 SAFETY SHOES, HARDHATS, AND GLASSES
Safety shoes, hardhats, and safety glasses worn by electrical workers shall meet the
of ANSI Z41, ANSI Z89.1, and ANSI Z87.1 specifications, respectively.
2.13 WORK PRACTICES
NFPA 70E covers electrical safety-related work practices and procedures for qualified and
employees who work on or near exposed energized electrical conductors or circuit
parts in workplaces. This information provides a foundation
for establishing an electrically safe
working environment. NFPA 70E has embedded four basic strategies in the document. These
1. establish an electrically safe work condition,
3. planning the work, and
4. personal protective equipment.
NFPA 70E is updated on a 3-year cycle in compliance with ANSI requirements. This schedule
allows for the latest acceptable technology
and experience to be integrated into the document.
Qualified workers shall be knowledgeable and trained in safety-related
work practices, safety
procedures, and other requirements that pertain to their respective job assignments. Employees
shall not be permitted
to work in an area where they are likely to encounter an electrical hazard
unless they have been trained to recognize and avoid these hazards.
(See Section 2.8.)
22.214.171.124 LIVE PARTS
Live parts to which an employee may be exposed shall be deenergized before the employee
works on or near them, unless it can be demonstrated that deenergizing introduces additional or
increased hazards or is infeasible because
of equipment design or operational limitations. (See
Live parts that operate at less than 50 volts to ground need
not be deenergized if there will be
no increased exposure to electrical burns or to explosion due to electrical arcs.
Safe procedures for deenergizing circuits and equipment shall be determined before circuits or
equipment are deenergized. Deenergization
procedures shall be included in the lockout/tagout
procedure for the circuit or equipment to be deenergized.
126.96.36.199 CIRCUITS AND
Circuits and equipment to be worked on shall be disconnected from all electric energy sources.
Control circuit devices such
as push-buttons, selector switches, and interlocks shall not be used
as the sole means for deenergizing circuits or equipment.
Figure 2-6. Employers shall implement and document a lockout-tag-out program
with procedures to safeguard
employees from injury while working on or
near deenergized systems.
188.8.131.52 STORED ELECTRICAL ENERGY
Stored electrical energy that might endanger personnel shall be placed in a safe state.
shall be discharged and high-capacitance elements shall be short-circuited and
grounded if the stored electrical energy could endanger personnel.
184.108.40.206 STORED NONELECTRICAL ENERGY
Stored nonelectrical energy in devices that could reenergize electric circuit parts shall be
blocked or relieved to the extent that the circuit parts could not be accidentally energized by the
device. Examples include wound springs
and pneumatic-driven devices.
220.127.116.11 LOCKOUT/TAGOUT PROCEDURE
Each employer shall document and implement lock-out/tag-out procedures
employees from injury while they are working on or near deenergized electric circuits and
equipment. The lock-out/tag-out
procedures shall meet the requirement of NFPA 70E 120.2, 29
CFR 1910.147(c) to (f), 1910.269(d) and (m), 1910.333, and 1926.417. (See Figure
2.13.2 VERIFICATION OF DEENERGIZED CONDITION
Verification shall be made that all live circuits, parts, and other sources of
including mechanical energy, have been disconnected, released, or restrained.
A qualified worker shall operate the
equipment operating controls, perform voltage verification,
and inspect open switches and draw out breakers to ensure that energy sources
18.104.22.168 VOLTAGE VERIFICATION TEST
A qualified worker shall use appropriate test equipment to test the circuit elements
parts of equipment to which employees will be exposed and shall verify that the circuit elements
and equipment parts are
deenergized. The test shall also determine if a hazardous energized
condition exists as a result of induced voltage or voltage back feed
after specific parts of the
Figure 2-6. Employers shall implement and document a lockout-tagout program with
procedures to safeguard employees
from injury while working on or near deenergized
circuit have been deenergized. If the circuit to be tested is over 600 V nominal, the test equipment
shall be checked for proper
operation immediately before and immediately after this test. This test
is also recommended for systems of 600 V or less. Testing shall be
performed as if the circuit is
energized. The voltage verification device used shall be rated for the application. Proximity testers
solenoid-type devices should not be used to test for the absence of alternating current (AC)
voltage. See 22.214.171.124 for further information.
126.96.36.199 APPLICATION OF GROUNDS
Personnel protective grounds shall be applied on circuits 600 V and above or on lesser voltages
residual charges may accumulate. Personal protective grounds shall be selected and
installed in accordance with appropriate standards. (See
sections 4.6 and 7.5). Consideration
shall be given to step and touch potentials in the area of the temporary ground connections.
2.13.3 REENERGIZING EQUIPMENT
The following requirements shall be met before circuits or equipment are reenergized, even
188.8.131.52 TESTS AND VISUAL INSPECTIONS
A qualified worker shall conduct tests and visual inspections to verify that all personnel are
clear and that all tools, electrical jumpers, shorts, grounds, and other such devices have been
removed so that the circuits and
equipment can be safely energized.
184.108.40.206 WARNING EMPLOYEES
Employees exposed to the hazards associated with reenergizing the circuit
or equipment shall
be warned to stay clear of circuits and equipment.
220.127.116.11 REMOVING LOCK AND TAG
Each lock and tag shall be
removed by applying the following:
1. Each lockout or tagout device shall be removed from each energy-isolating device by the
employee who applied the lockout or tagout device, or under their direct
supervision, or as stated below.
2. Exception: When the authorized
employee who applied the lockout or tagout device is not
available to remove it, that device may be removed under the direction of his or
supervisor. Extreme care shall be taken and specific procedures shall be followed, including,
at a minimum, the following elements:
a. Verification by the supervisor that the authorized employee who applied the device is not
at the affected facility
b. Making all reasonable
efforts to contact the authorized employee to inform him or her
that the lockout or tagout device has been removed
c. Ensuring that the
authorized employee has this knowledge before he or she resumes
work at the affected facility
2.13.4 SAFE ENERGIZED WORK (HOT WORK)
Safety-related work practices shall be used to prevent electrical shock or other electrically
induced injuries when employees work on or near electrical conductors or circuit parts that are
energized. Only qualified workers who are
knowledgeable and have been trained to work safely
on energized circuits and to use the appropriate PPE, protective clothing, insulating
materials, and insulated tools shall be permitted to work on energized conductors or circuit
No unqualified employee shall be permitted to approach or take any conductive object closer to
exposed, energized lines or parts
than the distance listed in NFPA 70E 130.26, Approach
Boundaries to Live Parts for Shock Protection.
18.104.22.168 TWO WORKERS
of the potential for exposure to energized parts, electrical work, independent of
voltage, that presents a significant shock or arc blast
hazard to employees, needs to be
evaluated as to the number of employees involved.
shall be provided before workers are allowed to enter spaces containing
exposed energized parts.
22.214.171.124 SYSTEMS UNDER LOAD
equipment intended to switch current shall have a rating sufficient for the current.
Manual switches and disconnects, taps, terminators,
and nonenclosed switches shall not be
operated while under load, unless the devices are rated as load-break type and are so marked.
126.96.36.199 WORKING WITH TEST INSTRUMENTS AND EQUIPMENT
Sometimes it becomes necessary to check the continuity of power circuits, control
by using a particular testing instrument (volt, ohm, and/or amp meter) designed for the testing
involved. The voltage
device used shall be rated for the application. Proximity testers and
solenoid-type devices should not be used to test for the absence of
voltage because they do not
accurately detect and/or measure voltage. Also, proximity testers will not detect direct current
(DC) or AC
voltage in a cable that is shielded. Proximity testers are very useful in certain
applications; for example, for finding cables that go through
a panel but that do not terminate in
the panel. However, it should be noted that a proximity tester’s failure to detect voltage does not
guarantee that the equipment or device is deenergized. The absence of voltage can only be
verified with a voltmeter rated for the application.
Voltmeters, both analog and digital, are designed for a number of applications from appliance
troubleshooting to power system testing.
The type of voltmeter used depends on where in the
power system you are using the meter. The user must read and understand the manufacturer's
instructions on the use and application of the voltmeter. When a multi-function, multi-scale
meter is used, it is important for the user
to select the function and scale necessary for the task
being performed in order to avoid damage or destruction of the meter and injury to
employee. The selection of test instruments and equipment shall be based on its application
should apply when working with test instruments and equipment on energized
188.8.131.52.1 QUALIFIED EMPLOYEES
qualified workers who have been trained to work safely with test
instruments and equipment on energized circuits shall be permitted to perform
testing work on
electrical circuits or equipment where there is danger of injury from accidental contact with
energized parts or improper
use of the test instruments and equipment.
184.108.40.206.2 VISUAL INSPECTIONS
Test instruments and equipment and all associated test leads,
cables, power cords, probes, and
connectors shall be visually inspected for external defects or damage before being used on any
If there are defects or evidence of damage that might expose an employee to injury, the
defective or damaged item shall not be used until
required repairs and tests have been made.
220.127.116.11.3 RATING INSTRUMENTS AND EQUIPMENT
Test instruments and equipment and their accessories
shall be rated for the circuits and
equipment to which they will be connected and shall be suitable for the environment in which
will be used.
18.104.22.168.4 CALIBRATION OF ELECTRICAL INSTRUMENTS
The American National Standards Institute (ANSI) standard C39.1 defines
performance and general requirements level for electrical instruments. ANSI standards also
ensure that an instrument, when
calibrated to National Institute of Standards and Technology
(NIST) traceable standards, is capable of transferring that quality of measurement
conditions within specified limits, where that level of measurement quality is needed.
A record should be maintained for each
instrument, by serial number or equivalent method,
showing dates of inspection, calibration data as received, the date when it should be
from the field and a recalibration check made, and any interim repairs. After a period of time, it
should become obvious what
frequency needs to be established for calibrating each instrument.