R.
James Seffrin Jersey
Infrared Consultants
P.O. Box 39
Burlington, NJ 08016
609-386-1281
Abstract
Although infrared
inspections of electrical equipment are a widely accepted
maintenance procedure, considerable debate exists among thermographers
concerning their safe conduct. This paper discusses the National
Fire Protection Association, NFPA Bulletin 70E, the Occupational
Safety and Health Administration and how they apply to infrared
inspections of electrical equipment.
Introduction
Infrared inspections of electrical distribution
equipment are now a widely accepted maintenance procedure.
Since electrical panels must be removed, thermographers often
come in close proximity to energized components.
This paper discusses the National Fire Protection
Association, NFPA 70E, the Occupational Safety and Health
Administration and how they apply to infrared inspections
of electrical equipment.
This paper is based upon research of existing
standards at the time of publication. It is not intended to
cover all standards and situations which a thermographer could
encounter in the course of his/her work. Thermographers and
their employers must be familiar with all current applicable
safety and health standards and should consult with their
local OSHA office to ensure compliance.
The
National Fire Protection Association
The National Fire Protection Association
has led the way to fire safety since 1896. The mission of
this international nonprofit organization is to reduce the
burden of fire on the quality of life by advocating scientifically
based consensus codes and standards, research, and education
for fire and related safety issues.
Just before the turn of the century, fire
was a major safety and economic issue in North America's crowded
cities and factories. In fact, fire death rates and property
loss from fire (relative to gross national product) were six
times today's levels.
Concerned with a lack of consistent sprinkler
installation practices, a small group of New England fire
insurance leaders and sprinkler manufacturers met in 1895
and recognized the need for one formal set of standards. Soon
after, a small group met in New York to begin drafting sprinkler
rules, and by March 1896, the draft rules were complete and
a committee began organizing. By November 1896, the National
Fire Protection Association was created.
Throughout its first 100 years, NFPA's diverse
activities have clustered around the broad themes of fire
safety and education, and technological advancement in fire
protection, which reflect the original objectives of the organization.
Presently headquartered in Quincy, Massachusetts,
NFPA's membership is over 68,000 people and more than 100
organizations in the United States, Canada and 70 other countries.
More than 5300 volunteer members of 205 Technical Committees
develop more than 300 codes and standards known collectively
as the National Fire Codes®.
The NFPA has no enforcement power; its standards
are merely advisory. However, the Association enjoys a unique
reputation for its technical accuracy and procedural fairness.
Consequently, for many years all levels of government have
adopted NFPA standards, giving many of them the force of law.
One of the many NFPA codes that has achieved
worldwide recognition, adoption, and enforcement is the National
Electric Code® . NFPA 70 addresses proper electrical systems
and equipment installation to protect people and property
from hazards arising from the use of electricity in buildings
and structures.
The
History of NFPA 70E
In January 1976, the Standards Council of
the National Fire Protection Association, Inc., announced
the appointment of a new electrical standards development
committee. The "Committee on Electrical Safety Requirements
for Employee Workplaces, NFPA 70E" was formed to assist OSHA
in preparing electrical safety standards that would serve
OSHA's needs and that could be expeditiously promulgated through
the provisions of Section 6(b) of the Occupational Safety
and Health Act. OSHA had found that in attempting to utilize
the latest edition of NFPA 70, National Electrical Code® (NEC),
it was confronted with several problem areas:
(a) Adopting a new edition of the NEC by
Section 6(b) procedures would require extensive effort and
resources by OSHA and others including public notice, comments,
and hearings. Going through the 6(b) procedures might result
in requirements substantially different than those of the
NEC, thereby creating potential conflict between the OSHA
standard and other national and local standards.
(b) The NEC is intended primarily for those
who design, install, and inspect electrical installations
and it is extremely difficult for the average employer and
employee to understand.
(c) Some of the detailed provisions within
the NEC are not directly related to employee safety and, therefore,
are of little value for OSHA's needs.
(d) Electrical safety-related work practices
and maintenance of the electrical system considered critical
to safety are not found in the NEC. However, OSHA must consider
and develop these safety areas in its regulations.
This led to the concept that a document be
written that would extract suitable portions from the NEC
and from other documents applicable to electrical safety.
This concept and an offer of assistance was accepted by the
Assistant Secretary of Labor in 1975.
A study by committee found it feasible to
develop a four-part standard for electrical installations
that would be compatible with the OSHA requirements for safety
for the employee in locations covered by the NEC.
The new standard was named NFPA 70E, Standard
for Electrical Safety Requirements for Employee Workplaces.
The new standard was first published in 1979 and contained
only Part I. Parts II and III were added in subsequent editions.
The February 7, 1995, edition does not include new parts;
however, it does contain extensive revisions to previous editions.
Part IV has not yet been published.
NFPA 70E is intended to serve a very specific
need of OSHA and is in no way intended to be used as a substitute
for the NEC. NFPA 70E is intended for use by employers, employees,
and OSHA.
NFPA
70E
The Introduction of 70E is divided into two
Parts: I-1 Scope and I-2 Definitions. The Scope reads as follows:
I-1.1 This standard addresses those electrical
safety requirements for employee workplaces that are necessary
for the practical safeguarding of employees in their pursuit
of gainful employment. This standard covers:
(a) Electric conductors and equipment wiring
installed within or on buildings or other structures, including
mobile homes and recreational vehicles, and other premises
such as yards, carnival, parking and other lots, and industrial
substations.
(b) Conductors that connect the installations
to a supply of electricity.
(c) Other outside conductors on the premises.
I-1.2 This standard does not cover:
(a) Installations in ships, watercraft, railway
rolling stock, aircraft, or automotive vehicles other than
mobile homes and recreational vehicles.
(b) Installations underground in mines.
(c) Installations of railways for generation,
transformation, transmission, or distribution of power used
exclusively for operation of rolling stock or installations
used exclusively for signaling and communication purposes.
(d) Installations of communication equipment
under the exclusive control of communication utilities, located
outdoors or in building spaces used exclusively for such installations.
(e) Installations under the exclusive control
of electric utilities for the purpose of communication or
metering; or for the generation, control, transformation,
transmission, and distribution of electric energy located
in buildings used exclusively by utilities for such purposes
or located outdoors on property owned or leased by the utility
or on public highways, streets, roads, etc., or outdoors by
established rights on private property.
I-1.3 This standard is divided into the following
four parts and two appendixes:
Part I, Installation Safety Requirements
Part II, Safety-Related Work Practices
Part III, Safety-Related Maintenance Requirements
Part IV, Safety Requirements for Special
Equipment (To be developed at a later date)
Appendix A, Tables, Notes, and Charts (Reserved)
Appendix B, Referenced Publications
Part
I, Installation Safety Requirements
Part I of this standard is divided into six
chapters dealing with the construction of electrical systems.
Since thermography is not construction related, Part II is
the applicable section for infrared inspection of electrical
systems.
Part II, Safety-Related Work Practices
Part II of this standard is divided into
five chapters. It covers electrical safety-related work practices
and procedures for employees who work on or near exposed energized
electrical conductors or circuit parts. The practices and
procedures are intended to provide for employee safety relative
to electrical hazards in the workplace.
The employer is responsible for providing
the safety-related work practices and training of the employees.
The employees are responsible for implementing the safety-related
work practices.
There are many references to "qualified"
and "unqualified" persons within NFPA 70E. From the standard's
definitions we find:
Qualified person. One familiar with the construction
and operation of the equipment and the hazards involved.
Unqualified person. A person who is not a
qualified person.
NFPA 70E states that only qualified persons
may work on or near energized electric circuits. Since infrared
inspections of electrical equipment will often require a thermographer
to come in close proximity to exposed live conductors, thermographers
must be Qualified Persons in order to comply with the standard.
Safety Training Chapter 2 requires that qualified
persons who work on or near energized equipment be trained
in the safety-related work practices and procedural requirements
as necessary to provide protection from the electrical hazards
associated with their respective job or task assignments.
They must also be trained in and familiar with:
(a) The skills and techniques necessary to
distinguish exposed energized parts from other parts of electric
equipment,
(b) The skills and techniques necessary to
determine the nominal voltage of exposed energized parts,
(c) The approach distances specified in Table
2-3.3.5 and the corresponding voltages to which the qualified
person will be exposed, and
(d) The decision-making process necessary
to determine the degree and extent of the hazard and the personal
protective equipment and job planning necessary to perform
the task safely.
Qualified persons must also be familiar with
the proper use of special precautionary techniques, personal
protective equipment, insulating and shielding materials,
and insulated tools and test equipment.
Qualified persons must also be trained in
and familiar with applicable emergency procedures such as
the release of victims from contact with exposed energized
conductors or circuit parts. They must receive regular training
in first aid and resuscitation.
Training may be conducted within the classroom
or through on-the-job training.
Electrical Safety Program NFPA 70E states
that the employer shall implement an overall electrical safety
program that directs activity appropriate for the voltage,
energy level, and circuit conditions.
The program must define its principles; the
controls by which it will be measured and monitored; and the
specific procedures for working on or near exposed energized
conductors and circuit parts. It must provide self-discipline
for employees and instill safety principles.
Job Briefings Job briefings are required
before the start of each job. Briefings are required at least
once per shift for repetitive work or more frequently if significant
work changes occur. Briefings can be short if employees understand
through training and experience the hazards involved; or more
extensive if the work is complicated or hazardous or the employee
cannot be expected to recognize and avoid the hazards involved
in the job.
Conductive Materials, Tools, and Equipment
Being Handled Work practices must be employed to safeguard
employees when work is performed on or near exposed energized
circuits. Work practices must protect employees from direct
bodily contact or contact through a conductive object. Work
practices must be suitable for the work conditions under which
the work is being performed and for the voltage levels of
the exposed circuits.
Personal and Other Protective Equipment NFPA
70E states that employees working in areas where there are
potential electrical hazards shall be provided with, and shall
use, protective equipment that is appropriate for the specific
parts of the body to be protected and for the work to be performed.
Protective equipment must be maintained in
a safe, reliable, sanitary condition and must be periodically
inspected or tested. Employees must wear personal protective
equipment for the head, face, neck, chin, eyes, ears, body
and extremities when determined necessary by the Hazard/Risk
Evaluation Procedure listed in 2-5.1.6.
Nonconductive flame-resistant head protection
is required when there is a danger of contact with exposed
energized parts or from falling objects. Where there is potential
exposure to arc flash burns, or to flying objects, head protection
must be supplemented by a cape, scarf, and full face shield
or hood with a viewing window.
Eye protection is required to protect from
flying or falling objects. Where there is potential exposure
to arc flash conditions, such protective equipment must protect
the eyes from the resulting thermal and luminous energy.
Employees are required to wear clothing resistant
to flash flame wherever there is possible exposure to an electric
arc flash. Flash Protection Boundaries are defined in Table
2-3.3.5 or may be calculated from the formulas printed in
2-3.3.3.2.
Use of Equipment NFPA 70E states that only
qualified persons may perform testing work on energized electric
circuits or equipment. All test equipment must be visually
inspected for external damage and defects prior to each use.
Equipment found to be damaged or defective must be removed
from service until it is repaired and rendered safe for use.
Test equipment must be rated for the circuits being tested
and operated only in the environments for which they are designed.
Safety Signs and Tags and Barricades When
normally enclosed live parts are exposed for maintenance or
repair, they must be guarded to protect unqualified persons
from contact with the live parts. The use of safety signs
and tags warning about electrical hazards, and barricades
are required to warn and protect employees. An attendant is
required when signs and barriers do not provide sufficient
warning and protection.
Several other work practices are addressed
for those who work on or near exposed energized parts. These
include lockout/tagout, overhead lines, illumination, confined
or enclosed work spaces, conductive material and equipment,
portable ladders, conductive apparel, housekeeping duties,
and interlocks. Thermographers must comply with all work practices
which are applicable to his/her work. Should a thermographer
defeat an interlock to gain access to a piece of equipment,
the safety interlock system must be returned to its operable
condition when the work is completed.
Of the above work practices, the applicability
of "Lockout and Tagout" confuses many thermographers. Simply
put, Lockout/Tagout is designed to prevent electrocution and
injury while a circuit is being worked on.
Since thermography requires that circuits
be energized, Lockout/Tagout does not directly affect thermography
other than de-energizing certain equipment. Thermographers
should be aware of the importance of Lockout/Tagout and must
never remove or tamper with tags and locks unless they are
qualified to do so.
Part
III, Safety-Related Maintenance Requirements
Part III of this
standard is divided into eleven chapters dealing with the
maintenance of electrical equipment and installations. Since
thermography is solely inspection and not maintenance, Part
III is not applicable for infrared inspections.
Conclusion
Presently, NFPA 70E serves as a written safety
standard for the inspection of energized electrical distribution
systems. While some of the requirements are redundant to OSHA's
1910, NFPA 70E is more comprehensive.
Since NFPA 70E was developed for the Occupational
Safety and Health Administration, it is a standard that OSHA
will almost certainly reference. Enforcement seems likely
for many if not all principles of NFPA 70E since much of the
content of NFPA 70E parallels OSHA 1910.
For those involved in the generation and
transmission of electricity, OSHA 1910 Subpart R will continue
to serve as a reference standard.
Thermographers and their employers must identify
how the NFPA and OSH standards apply to their work and ensure
that they are in compliance. Failure to comply can result
in fines and criminal penalties.
References
OSHA Home Page, U. S. Department of Labor,
Occupational Safety and Health Administration, http: / / www.osha.gov
Public Law 91-596, Occupational Safety and
Health Act of 1970, amended November 5,1990.
Occupational Safety and Health Standards
for General Industry, Part 1910, U. S. Department of Labor,
Occupational Safety and Health Administration, http: / / www.osha.gov
NFPA Home Page, U. S. Department of Labor,
Occupational Safety and Health Administration, http: / / www.nfpa.org
