Life is full of surprises, and so is the 2018 edition of NFPA 70E. After years of requiring specific information on arc flash equipment labels, as listed in 130.5(H1) through (H3), the 2018 edition has introduced Exception No. 2 to 130.5(H), which states this information may no longer be required, subject to meeting certain conditions. Wait… what?
The exact text of the new Exception No. 2 is: “In supervised industrial installations where conditions of maintenance and engineering supervision ensure that only qualified persons monitor and service the system, the information required in 130.5(H)(1) through 130.5(H)(3) shall be permitted to be documented in a manner that is readily available to persons likely to perform examination, servicing, maintenance, and operation of the equipment while energized.
“(H)(1) Nominal system voltage
“(H)(2) Arc flash boundary
“(H)(3) List at least one of the following: Available incident energy and the corresponding working distance or the arc flash PPE category, minimum arc rating of clothing, site-specific level of PPE.”
This could be a game changer, so let’s look at the details. To use this exception, several conditions must be met that include the following terms.
Supervised industrial installation: Although NFPA 70E does not define this term, it is considered to be an installation with a load used in industrial processes, manufacturing activities or both with additional terms addressed below.
Conditions of maintenance: The 2018 edition of NFPA 70E added a new definition for “Condition of Maintenance,” which is the state of the electrical equipment considering the manufacturers’ instructions, manufacturers’ recommendations and applicable industry codes, standards and recommended practices.
Engineering supervision: This is another term that is not specifically defined; however, it is generally considered that there is a qualified engineering person(s) available for supervision.
Qualified person: According to the NFPA 70E definition, a qualified person is one who has demonstrated skills and knowledge related to the construction and operation of electrical equipment and installations and has received safety training to identify the hazards and reduce the associated risk.
Documented: The referenced documentation for (H)(1) though (H)(3) could be in the form of an arc flash study report. This is similar to a short-circuit study where, other than a few requirements in the National Electrical Code (NEC), the calculated values from the study are not normally listed on the equipment but rather are documented in a report.
Configurations—a moving target
Why the sudden about-face? It is widely recognized that industrial power systems often are not limited to only one operating configuration. Due to process and maintenance requirements and maintaining operation during equipment failures, it may sometimes be necessary to reconfigure the power system.
With every reconfiguration, the available fault current, and possibly the protective device operating times, can change—resulting in a different incident-energy and arc-flash boundary. Previously, there were normally two options available for this situation: either install multiple labels for different configurations or use the worst-case scenario. Each option introduces additional problems. Multiple labels can create confusion, and using the worst-case scenario can lead to requiring PPE of a higher arc rating—not usually desirable by the worker if it is not necessary.
This new exception would enable industrial users, who meet the strict requirements outlined in the exception to ensure qualified persons, to have the correct information based on the specific configuration.
NEC arc flash label requirements
Just because Exception 2 provides conditions where detailed information may no longer be required on the label, the need for labels has not been eliminated. The NEC still has its requirements.
110.16, Arc Flash Hazard Warning: Electrical equipment, such as switchboards, switchgear, panelboards, industrial control panels, and motor control centers that is in other than dwelling units and is likely to require examination, adjustment, servicing or maintenance while energized, shall be field marked to warn qualified persons of potential electric arc flash hazards.
This could be a game-changer
Is there going to be a mad rush for studies to no longer include detailed information on the labels when conditions of Exception 2 are met? Time will tell, but regardless of whether the information is included or not, one thing will not change. The need for labels has not been eliminating electrically safe working condition. The last two words of Exception 2, “while energized,” will hopefully be the true exception.
Note: This article should not be considered a direct or implied interpretation of NEC or National Fire Protection Association standards.