Origin and Development of NFPA 791
The Technical Committee on Electrical Equipment Evaluation was organized in 2008 by
NFPA in recognition of the need for requirements for the qualifications and competency of
third-parties performing field evaluations on electrical products and assemblies and to guide
the process for field evaluations.
One means to demonstrate conformance of products to an applicable product safety standard
is through certification. Historically, certification was accomplished through a laboratory investigation
of a prototype or initial sample to determine compliance with the standard, with a system of
ongoing follow-up inspections conducted to continue certification. The result was a “Certification,”
“Listing,” “Recognition,” or “Classification” of the product as defined by various standards,
including NFPA 70, National Electrical Code®. These processes were formalized in several international
standards, including ISO/IEC Guide 65, General Requirements for Bodies Operating Product
Certification Systems, and ISO/IEC Standard 17020, General Criteria for the Operation of Various Types of
Bodies Performing Inspection.
As the marketplace evolved, more and more products needed to be evaluated differently
from the above system because they were already installed at the installation site. Another
condition that did not fit the normal process and required some other process of evaluation
was that some products needed to be evaluated but were not produced in quantities that fit
the traditional certification model economically. The alternative process to meet the needs
for evaluation of unique, modified, or other equipment beyond the manufacturing process
became known as a “field evaluation.” The process used for field evaluations, by the nature of
the work, is a blend of ISO/IEC Guide 65 and ISO/IEC Standard 17020.
In 2008, a task group identified the need to create two documents covering the performance
of field evaluations of electrical equipment and used the following document as the
basis for development: Recommended Competency Guidelines for Third Party Field Evaluation Bodies,
which was developed by the American Council for Electrical Safety (ACES), a division of the
American Council of Independent Laboratories (ACIL) (first edition, November 17, 2005).
The ACES document provided guidelines regarding the competency of firms that perform