By Corey Hannahs, Contributor
“…do this, don’t do that – can’t you read the sign?” The year was 1971 and I certainly find some irony in the fact that the original band to perform this well-known ditty was dubbed as the Five Man Electrical Band. In a rare case of double irony, there was a remake of the song in 1990 by a band named Tesla. With names like the Five Man Electrical Band and Tesla taking the lead on this song, it leaves little doubt that electricity and signs were meant to be united. If you listen closely to the lyrics of the song, it doesn’t necessarily portray signs in the best light (see what I did there?). The songwriter depicts signs as being controlling and limiting to individuals who may look or act differently than what may be considered as the norm. For someone who is looking for unlimited freedom to do whatever they choose, signs can certainly be seen as restrictive and unnecessary. But when it comes to ensuring the safety of individuals working around electricity, signs can be a critical factor in determining life, or death.
NFPA 70®, National Electrical Code® (NEC®), and NFPA 70E© Standard for Electrical Safety in the Workplace® are two of the three components that are crucial to the electrical Cycle of Safety, with NFPA 70B® Recommended Practice for Electrical Equipment Maintenance® being the third. While the purpose of the NEC is to safeguard persons and property from hazards that may arise from the use of electricity, NFPA 70E provides enforceable responsibilities for both employers and employees to protect workers from exposure to electrical hazards. So, while the focus of the NEC is on safe installations, NFPA 70E exists to help ensure that the installation is done safely by the individual(s) performing the work. With that said, it becomes easier to see how the NEC and NFPA 70E must be applied together in harmony to ensure the safety of both people and property within any given scenario that is dealing with electricity.
Signs, or “labeling” (not intended to imply product labeling by a listed laboratory) as they are often referenced, can be seen regularly within the NEC as well as NFPA 70E. NEC section 110.16(B) deals specifically with labeling of service equipment rated at 1200 amps or more, maintaining that the label itself must meet the requirements of NEC section 110.21(B), which deals with label design, affixation, and durability as well as containing the following information:
- Nominal system voltage
- Available fault current at the service overcurrent protective devices
- The clearing time of service overcurrent protective devices based on the available fault current at the service equipment
- The date the label was applied
The exception within NEC section 110.16(B) states that “service equipment labeling shall not be required if an arc flash label is applied in accordance with acceptable industry practice.” Such accepted industry arc flash labeling practices reside within NFPA 70E. As a means of tying the NEC installation requirements back into NFPA 70E, Informational Note No. 3 within NEC section 110.16(B) goes on to note NFPA 70E as covering labeling information stating that “Acceptable industry practices for equipment labeling are described in NFPA 70E-2018 Standard for Electrical Safety in the Workplace. This standard provides specific criteria for developing arc-flash labels for equipment that provides nominal system voltage, incident energy levels, arc-flash boundaries, minimum required levels of personal protective equipment, and so forth.”
For the Purpose of Safety
So, you may be asking yourself, where does the information we are talking about being listed on the labeling come into play as far as safety? Much of this information can be utilized for risk assessment as well as personal protection equipment (PPE) selection, should we get to that level as we work our way through the Hierarchy of Risk Control Methods as listed within NFPA 70E section 110.5(H)(3). Understanding the known risk(s) and having the information needed allows us to make a well-educated decision, including choosing proper PPE when deemed necessary.
Stepping back and taking a bird’s eye view of both the NEC and NFPA 70E, let’s again look at the purpose of each document. The NEC is about the practical safeguarding of both people and property from the hazards that arise due to the use of electricity. NFPA 70E is focused on the safety of those individuals who are performing the work. When we look at the contents of the required labeling in each standard, we see a clear picture of the purpose of each document come to life. Required labeling within the NEC primarily focuses on available fault current and short-circuit current rating (SCCR), both of which focus on the equipment itself. A miscalculation of either utilized to purchase equipment being installed, or replaced, could result in a catastrophic event that could impact the building structure and likely people within the vicinity as well. Not to mention the daunting task of getting an outage of all, or part of, the electrical system back up and running. Service equipment such as switchboards, switchgear, and panelboards are crucial pieces within the electrical distribution system. And arguably some of the most serviced and modified equipment after the initial installation takes place. Even in future alterations to the electrical distribution system, it is crucial to make sure that the available fault current and SCCR ratings of any new equipment is sized properly.
The 2020 cycle of the NEC took another step toward safety within section 408.6 by adding a requirement that states all switchboards, switchgear, and panelboards must have a SCCR not less than the available fault current. It goes on to add a labeling requirement on the equipment that states both the available fault current and the date the calculation was performed, data that would prove invaluable when it comes to properly sizing additional or replacement equipment. While the NEC doesn’t have any labeling requirements that are specific to directly establishing safety for individuals working on the electrical system, the aforementioned NEC section 110.16(B) Informational Note No. 3 points us to NFPA 70E which does. Information such as arc-flash boundaries, incident energy levels, and minimum required levels of PPE contained within NFPA 70E developed arc-flash labels have a direct impact on the safety of the individual(s) working on the equipment.
Understanding safe work distances and the equipment needed to keep you safe, should you have to work inside those distances, are critical pieces to maintaining personal safety. All things considered, NEC section 110.16(B) Informational Note No. 3 is our safety ribbon that ties both the NEC and NFPA 70E together, solidifying a shield of safety for both property and people. Labeling, as applied by both the NEC and NFPA 70E, is our sign. Don’t ignore the signs, they often point toward safety.
Corey Hannahs is an Electrical Content Specialist at the National Fire Protection Association (NFPA). In his current role, he serves as an electrical subject matter expert in the development of products and services that support NFPA documents and stakeholders. He can be reached at email@example.com.