The requirements of NFPA 70E do not affect electrical conductors and circuit parts installations, which are under NFPA 70, the National Electrical Code. NFPA 70E addresses electrical safety-related work practices, safety-related maintenance requirements and other administrative controls for employee workplaces necessary for the practical safeguarding of employees relative to the hazards associated with electrical energy.
However, informative Annex O in 70E does address safety-related design concepts and facility owner requirements. Annex O discusses the responsibilities of the facility owner, manager or employer to perform a risk assessment during the design of electrical systems and installations.
It is only during the design stage that many of these concepts can be incorporated into the electrical distribution system. The design considerations discussed therein have an impact on the application of the safety-related work practices only.
Design options that reduce the likelihood of exposure to electrical hazards or reduce the associated risk will enhance the effectiveness of safety-related work practices. Design options can enhance electrical safe work practices by
Reducing the likelihood of exposure, such as through the use of finger-safe components
Reducing the magnitude or severity of exposure, such as through arc energy reduction methods
Enabling achievement of an electrically safe work condition, by installing disconnects within sight of equipment.
Designers must understand that an installation in strict compliance with the NEC is the least they can do. The NEC contains minimum installation requirements only. Designers can—and should—go above and beyond where installations can be modified to enhance safe electrical work practices.
These additional design considerations may add additional cost to an installation. However, the net benefits are extremely significant. Design modifications can eliminate a costly outage and eliminate or reduce the potential for injury or fatality.
After an incident, injury or fatality, design issues are always discussed: “If only we had installed a redundant means to supply equipment, current limiting fuses, remote capabilities to open/close circuit breakers, remote racking” and much more. The minimal associated cost involved when we apply safety-related design concepts look attractive after an incident, injury or fatality.
Moving to the NEC
Many concepts found in Annex O are slowly making their way into the NEC as mandatory electrical installation requirements. For example, the 2023 NEC has modified, clarified and expanded the requirements in Section 110.16(B) for an arc flash label in accordance with applicable industry practice. The generic requirement for an arc flash hazard warning label still exists in 110.16(A) and applies to all equipment such as switchboards, switchgear and motor control centers, in other than dwelling units, that is likely to require examination, adjustment, servicing or maintenance while energized. This generic label only warns qualified persons of potential electric arc flash hazards. The prescriptive requirements in 110.16(B), however, mirror the equipment labeling requirements in NFPA 70E Section 130.5(H).
The 2023 revisions in NEC 110.16(B) are significant. They require an arc flash label in accordance with applicable industry practice and the date the label was applied.
The requirement no longer mandates the labeling of available fault current at the service overcurrent protective devices (OCPDs) and the clearing time of service OCPDs based on the available fault current at the service equipment.
Additional modifications include the expansion of the requirement to include services and all feeder-supplied equipment with the ampere threshold reduced from 1,200A to 1,000A. This is a game-changer and will mandate an arc flash label in accordance with NFPA 70E 130.5(H).
It is possible designing engineers will realize that, because they already must label each service/feeder rated 1,000A or more, they can expand the arc flash labeling throughout the entire distribution system at a very small cost. There is no need to stop at 1,000A—why not label every feeder?
About The Author
DOLLARD is retired safety coordinator for IBEW Local 98 in Philadelphia. He is a past member of the NEC Correlating Committee, CMP-10, CMP-13, CMP-15, NFPA 90A/B and NFPA 855. Jim continues to serve on NFPA 70E and as a UL Electrical Council member. Reach him at [email protected].