New Exception 130.5(H) Exception No. 2 – Arc Flash Label Information May Not Be Required.
It is amazing how the requirements for arc flash labels have evolved with each new edition of NFPA 70E. Known as Arc Flash Warning Labels by the National Electrical Code and Equipment Labels according to NFPA 70E 130.5(H), most people simply refer to them as arc flash labels.
What first began as a simple requirement to warn people of the arc flash hazard, has morphed into a list of required information found in NFPA 70E 130.5(H). As an example the evolution of label requirements was the information to aid in selecting Personal Protective Equipment and Arc Rated Clothing. In the past, the requirements began with Hazard Risk Category Tables, then it became using the Hazard Risk Category Tables OR the calculated incident energy. Today the Hazard Risk Category Table is now the PPE Category Table and there is an array of options listed in 130.5(H). Another evolution was with the term originally known as Flash Protection Boundary. It was later changed to Arc Flash Protection Boundary and finally to Arc Flash Boundary. It is interesting to look at labels today and see what term is being used. You still see some of the earlier terms but regardless of terminology, the Arc Flash Boundary remains as the distance (approach limit) from an arc source where the incident energy is 1.2 calories/centimeter2 (cal/cm2). This is boundary is for the case when an arc flash hazard exists.
Fast forward to the 2018 Edition of NFPA 70E and yet another change to the labeling requirements has been added. 130.5(H) Exception No. 2 now permits eliminating the detailed information from the arc flash label!
No Information on the Label??!! What? Huh? Are you kidding me?
I’m not kidding and besides, April Fool’s Day is over two months away.
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.
130.5 H(1) through (H)(3) are as follows:
- (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 new exception may be one of those proverbial “shots heard round the world” so let’s look at the details. First off, to actually 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 change in labeling philosophy? It is pretty common knowledge that industrial power systems often are not limited to only one operating configuration. Multiple sources, ties, generators, the list goes on. Due to process and maintenance requirements and maintaining operation during equipment failures, it may sometimes be necessary to reconfigure the power system and the arc flash study was an attempt at hitting a moving target – with the target being the system configuration.
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. Prior to the addition of this new exception, there were generally only two available options for this situation:
- Install multiple labels for different configurations or
- Use the worst-case scenario.
Each option has its draw-backs. Using multiple labels can create confusion, and using the worst-case scenario can lead to requiring PPE of a higher arc rating than necessary for the normal configuration —not usually desirable by the worker if it is not necessary.
This new exception provides a method for industrial systems, that meet the strict requirements outlined in the new exception to ensure qualified persons 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.
Is there going to be a big push for studies to no longer include detailed information on the labels when conditions of Exception 2 are met? It is too early to know, but regardless of whether the detailed information is included or not, there is one thing will not change. The emphasis for equipment to be placed into an electrically safe work condition. The last two words of Exception 2, “while energized,” will hopefully be the true exception.
Note: Although I am the Vice-Chair of IEEE 1584, International Chair of IEC TC78 and Member of the Steering Committee of the IEEE/NFPA Arc Flash Collaborative Research, this article should not be considered a direct or implied interpretation of NEC, National Fire Protection Association, IEEE or any other standards.
Based on my article originally published in Electrical Contractor Magazine – November 2017
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