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
qualified persons shall perform electrical repairs. Once a problem is discovered while
maintaining electrical equipment, any further work on this component or
system must be suspended until the
associated corrective actions are processed through a
work control 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
infeasible 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, tagged,
and/or locked according to an approved procedure and should be proven
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 or
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
(PPE) requirement identified in NFPA 70E is intended to protect against physical trauma
than exposure to the thermal effects of an arc flash.
2.1.2 CONSIDERATIONS FOR WORKING ON
ENERGIZED SYSTEMS AND
Qualified employees performing such tasks as electrical repairs,
modifications, and tests on
energized electrical systems, parts, and equipment need to comply with the
1. Parts to which an employee might be exposed shall be put into an electrically safe work
condition 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
purposes, unless they work under the direct supervision of a qualified person.
3. Sufficient 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
hazard to employees.
Note: The discussion in #4 above assumes the system voltage is less than the maximum
voltage of the ASTM class of rubber goods used.
2.1.3. SAFETY WATCH RESPONSIBILITIES AND
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
taking necessary action to ensure abatement of the unsafe condition or
work practice, deenergizing equipment
and alerting emergency-rescue personnel as
conditions warrant, maintaining visual and audible contact with
personnel performing the
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
performance of electrical work to qualified and competent personnel. Specifically, the
law requires 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.
One 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
proper steps taken by a qualified person.
The following, where used, will improve the safety of
1. Maintain good housekeeping and cleanliness.
2. Identify and control potential hazards.
3. Anticipate problems.
4. Resist pressure to "hurry up."
5. Plan and analyze for safety in each step of a
6. Document work.
7. Use properly rated test equipment and verify its condition and operation before and after
8. Know and practice applicable emergency procedures.
9. Become qualified in CPR and first aid and
maintain current certifications.
10. Wear appropriate PPE.
11. Refer to system drawings and perform system
12. Electrical equipment should be maintained in accordance with the manufacturer’s
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
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
To ensure safety and protection of employees, managers have the following
1. Ensure that employees are provided a workplace that is free from recognized hazards.
Ensure that employees performing electrical work are trained and qualified (see Section
3. Ensure that
approved, maintained, and tested personal protective equipment and clothing is
provided, available, and used
4. Establish, implement, and maintain procedures and practices that will ensure safe conduct
5. Keep and maintain records as required.
2.3.2 EMPLOYEE RESPONSIBILITIES
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
the AHJ or authorized designee to verify compliance with the codes and standards in
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. OSHA considers
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 Recognized Testing
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
authority responsible for enforcing the Code. For example, this would apply to custom-made
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
Workers who perform electrical
or electronic work, where applicable, shall comply with relevant
DOE Orders that may identify the following
codes and standards.
1. Standards published by the National Fire Protection Association (NFPA)
National Electrical Safety Code, ANSI C2.
3. All relevant state and local requirements.
4. Components or
installations in aircraft, watercraft, and railroads are exempt from the
above approval requirements.
The standards and performance specifications from the following organizations are
recommended and should be
observed when applicable:
1. Institute of Electrical and Electronics Engineers (IEEE)
2. National Electrical Manufacturers Association
3. American National Standards Institute (ANSI)
4. American Society for Testing and Materials (ASTM)
5. National Fire Protection Association (NFPA)
Underwriters Laboratory, Inc. (UL)
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
requirements of the above codes, standards, and regulations, the requirements that address the
particular hazard and provide the greater safety shall govern.
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.
Ground-fault 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
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 electrician or
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.
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.
Figure 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
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
an employee 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 a current
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
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 installations;
a) All 120-V, single-phase, 15-, 20-, and 30-A receptacle outlets that are or are not a part of
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.
GFCIs shall be trip-tested according to the manufacturer’s instructions.
Figure 2-2. There are three methods of providing GFCI protection for construction sites
2.7.3 ARC FAULT CIRCUIT INTERRUPTERS (AFCIs)
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
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
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 ability
to detect and interrupt arcing faults.
Although NEC 210.12 requires that AFCI protection be provided on
branch circuits that supply
outlets (receptacle, lighting, etc.) in dwelling unit bedrooms, there is no
providing AFCI protection on other circuits or location other than the bedrooms. For
aircraft wire systems utilize AFCIs for newer installation to trip the circuit routed through
sensitive areas such as fuel storage areas.
2.8 TRAINING AND QUALIFICATIONS OF QUALIFIED WORKERS
qualified workers shall perform work on electrical systems. It is dangerous for unqualified
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
respective job assignments.
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 parts of
3. Skills and
techniques necessary to determine the nominal voltage of exposed live parts,
clearance distances, and the
corresponding voltages to which the qualified person will be
4. Procedures on how to perform their
jobs safely and properly.
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) (2002)
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
i. Standard for Electrical Safety in the Workplace (NFPA 70E)
29 CFR 1910.269(a) and 1910.332 also require training for persons other than qualified workers
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
and trained at levels commensurate with their duties.
2.9 WORKING SPACE AROUND ELECTRICAL EQUIPMENT
Working 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.
Spacing shall provide the dimensional clearance (discussed in the following subsections) for
to equipment likely to require examination, adjustment, servicing, or
maintenance while energized. Such
equipment include panel boards, switches, circuit breakers,
switchgear, controllers, and controls on heating
and air conditioning equipment.
These clearances shall be in accordance with NESC and NEC. These working clearances are
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
NEC 110.26 states that a minimum working space 30 in. wide shall be provided in front of
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 parts, a
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 ft,
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 on the
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
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,
switchgear, and motor controllers.
There are three conditions to apply:
Where there are exposed live components on one side of a space and no live or
ungrounded parts on the other
2. Where there are exposed live components on one side and grounded parts on the other
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.
NEC Table 110.34(A)
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 or
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
2.10.3 ENCLOSURE LABELING
Printed labeling or embossed identification plates affixed to
enclosures shall comply with the
requirements that disconnects be legibly marked and that the marking shall be
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
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
with instructions pertaining to the electrical work.
2.11.1 SAFE WORK INSTRUCTIONS AND
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
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
Electrical instructions should be based on a thorough analysis of the job and its hazards. If the
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 430.7
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
should contain the essential safety rules for the job and, when documented, should be signed
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 equipment
Testing of equipment to ensure safe conditions
5. Provision of rubber-insulated protective equipment rated for
the highest voltage present
6. Qualified personnel (see 2.1.2 and 2.1.3)
7. PPE and protective clothing
(e.g., hardhats, safety shoes, eye and face protection,
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 prior to
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. Equipment that
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 testing in
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
shall not be more than 6 months for gloves and 12 months for sleeves and blankets. Gloves or
sleeves that have been electrically tested but not issued for service shall not be placed into
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
22.214.171.124 TESTING APPARATUS
apparatus shall be operated and maintained by personnel trained for such work.
Calibration schedules and
procedures for calibrating testing apparatus are recommended to be
in accordance with ANSI C39.1.
126.96.36.199 RETESTED PPE
Retested 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
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.
188.8.131.52 FIBERGLASS-HANDLED TOOLS
tools shall be tested by the manufacturer at 100 kV per ft of length. The in-service
test shall be 75 kV per
184.108.40.206 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
covers, line hose, sleeves, and gloves shall be as follows:
Class Voltage Label Color
00 500 Beige
0 1,000 Red
1 7,500 White
2 17,500 Yellow
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:
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
rolled provided the inner diameter of the roll is at least 2 in.
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 cuff-down in
a bag, box, or container designed for rubber glove storage. Rubber gloves may be kept
2.12.9 SAFETY SHOES, HARDHATS, AND GLASSES
Safety shoes, hardhats, and
safety glasses worn by electrical workers shall meet the
requirements of ANSI Z41, ANSI Z89.1, and ANSI Z87.1
2.13 WORK PRACTICES
NFPA 70E covers electrical safety-related work practices and procedures for
unqualified 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
environment. NFPA 70E has embedded four basic strategies in the document. These
establish an electrically safe work condition,
3. planning the work, and
NFPA 70E is updated on a 3-year cycle in compliance with ANSI requirements. This
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.)
220.127.116.11 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
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.
18.104.22.168 CIRCUITS AND EQUIPMENT
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.
22.214.171.124 STORED ELECTRICAL ENERGY
Stored electrical energy that might endanger personnel shall be placed
in a safe state.
Capacitors shall be discharged and high-capacitance elements shall be short-circuited and
grounded if the stored electrical energy could endanger personnel.
126.96.36.199 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.
Each employer shall document and implement lock-out/tag-out procedures to safeguard
employees from injury while they are working on or near deenergized electric circuits and
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 2-6.)
2.13.2 VERIFICATION OF DEENERGIZED CONDITION
Verification shall be made that all live circuits, parts, and other sources of electrical energy,
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 are isolated.
188.8.131.52 VOLTAGE VERIFICATION TEST
A qualified worker shall use
appropriate test equipment to test the circuit elements and electrical
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
recommended for systems of 600 V or less. Testing shall be performed as if the circuit is
voltage verification device used shall be rated for the application. Proximity testers
devices should not be used to test for the absence of alternating current (AC)
voltage. See 184.108.40.206 for
220.127.116.11 APPLICATION OF GROUNDS
Personnel protective grounds shall be applied on circuits 600 V and above or on lesser voltages
where residual charges may accumulate. Personal protective grounds shall be selected and
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
following requirements shall be met before circuits or equipment are reenergized, even
18.104.22.168 TESTS AND VISUAL INSPECTIONS
A qualified worker shall conduct tests and visual inspections to verify
that all personnel are in the
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.
Employees exposed to the hazards associated with reenergizing the circuit or equipment shall
be warned to stay clear of circuits and equipment.
22.214.171.124 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
authorized employee who applied the lockout or tagout device, or under their
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 her
supervisor. Extreme care shall be taken and specific procedures shall be followed, including,
at a minimum, the
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
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
on energized circuits and to use the appropriate PPE, protective clothing, insulating shielding
materials, and insulated tools shall be permitted to work on energized conductors or circuit
126.96.36.199 APPROACH DISTANCE
No unqualified employee shall be permitted to approach or take any conductive object
exposed, energized lines or parts than the distance listed in NFPA 70E 130.26, Approach
to Live Parts for Shock Protection.
188.8.131.52 TWO WORKERS
Because 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.
Adequate illumination shall be provided before workers are allowed to enter spaces containing
184.108.40.206 SYSTEMS UNDER LOAD
Electrical equipment intended to switch current shall have a rating
sufficient for the current.
Manual switches and disconnects, taps, terminators, and nonenclosed switches shall
operated while under load, unless the devices are rated as load-break type and are so marked.
220.127.116.11 WORKING WITH TEST INSTRUMENTS AND EQUIPMENT
Sometimes it becomes necessary to check the continuity of
power circuits, control circuits, etc.,
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
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
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 the
employee. The selection of test instruments and equipment shall be based on its application
The following should apply when working with test instruments and equipment on
18.104.22.168.1 QUALIFIED EMPLOYEES
Only knowledgeable, 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
energized parts or improper use of the test instruments and equipment.
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
shift. 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.
22.214.171.124.3 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
they will be used.
126.96.36.199.4 CALIBRATION OF ELECTRICAL INSTRUMENTS
The American National Standards
Institute (ANSI) standard C39.1 defines the minimum
performance and general requirements level for electrical
instruments. ANSI standards also
ensure that an instrument, when calibrated to National Institute of Standards
(NIST) traceable standards, is capable of transferring that quality of measurement to field
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 recalled
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.