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Author(s): Derek Vigstol. Published on September 4, 2018.

In Compliance | NEC

The triad of electrical safety


At NFPA, we often answer questions on installation requirements and safe work practices and electrical hazards by using a combination of proper installation and working safely. However, we rarely get inquiries asking what to do after the work is done—how can electrical equipment be safely maintained?

When it comes to maintenance, equipment that has no visible moving parts can be easily forgotten. The problem is that even though we don’t see them, there are moving parts. Electrons travel from atom to atom, conductor material expands and contracts from the constant heating and cooling caused by current flow, and magnetic forces put stress on internal components. All of this can lead to loose terminations, equipment deformation, and breakdown of design features meant to protect equipment from failure.

Each member of the NFPA 70® family of documents—the National Electrical Code® (NEC®); NFPA 70E®, Electrical Safety in the Workplace®; and NFPA 70B, Recommended Practice for Electrical Equipment Maintenance—addresses maintenance in a slightly different way. The NEC is an installation standard intended to protect people and property from the hazards that arise from the use of electricity by establishing installation practices that prevent fires or electrocutions. Equipment incorporating technologies such as AFCI and GFCI and installation procedures such as using a calibrated torque tool for terminations requiring a set torque value are just two examples of how the NEC achieves its purpose. At the time of installation, requirements like these will provide an installation that is essentially free of hazards to people and property.

Over time, though, equipment needs regular maintenance to remain effective. Section 110.3(B) requires that listed equipment be installed and used in accordance with any instructions included with its listing, and therefore listed devices like AFCI and GFCI come with requirements to regularly test their functionality. Who is going to make sure these devices are tested after the installation is turned over? And how about the torque values on those terminations?

NFPA 70E takes a slightly different approach to maintenance than the NEC but is still aimed at protecting people. Chapter 2 contains requirements for maintenance of electrical equipment in order to provide a safe working environment by reducing the risk to employees from equipment failure. Article 205 contains requirements for general maintenance that must be incorporated into a facility’s overall electrical safety program. Procedures like maintaining overcurrent protective devices in accordance with manufacturer’s instructions ensure that these devices operate as designed when needed. There are also installation requirements for working space, warning signs, and electrical continuity of grounding and bonding pathways.

The rest of Chapter 2 contains requirements for maintenance of equipment that could potentially pose a physical risk to employees if maintenance is not performed, such as maintaining switchgear enclosures and insulation integrity; covers designed to prevent accidental contact must be maintained to provide continued protection; portable tool cords and connections must be maintained so as not to be a shock hazard; battery room ventilation systems must be maintained to ensure adequate ventilation of hazardous gases; and personal protective equipment such as rubber insulating gloves and protective clothing must be maintained in a safe working condition.

The important part about the NFPA 70E maintenance requirements is that there needs to be consideration for maintenance when developing an electrical safety program, and there are maintenance procedures that must be included. A proper electrical safety program must stress maintenance in order to reduce the risk to employees from failure of equipment.

Finally, NFPA 70B contains recommendations for maintenance to reduce hazards to life and property from failure of equipment. A large portion of the document is aimed at providing a better understanding of the benefits of a well-administered and effective electrical preventive maintenance (EPM) program. In addition to reducing hazards from equipment failure, NFPA 70B stresses many benefits such as continued business operation and longevity of electrical equipment. The document also provides guidance for developing an effective EPM program to work in conjunction with an electrical safety program such as one designed based on NFPA 70E. As with NFPA 70E, though, NFPA 70B is a voluntary document and is only effective when facilities take the initiative to follow its recommendations.

The NFPA 70 documents have been described as the “three-legged stool” of electrical safety—it’s most effective when all three legs are in place. Remove one, however, and it may no longer be able to stand on its own.

DEREK VIGSTOL is an NFPA technical lead, Electrical Tech Services.