Safe Installations, Safe Work Practices
How NEC and NFPA 70E work together for greater electrical safety.
NFPA Journal®, September/October 2009
The last several revision cycles of NFPA 70, National Electrical Code® (NEC®), have yielded new and revised installation requirements intended to enhance the safety of those who work on electrical systems, many of them based on the requirements of NFPA 70E®, Electrical Safety in the Workplace®.
Among these changes is the revision of the long-standing definition of "qualified person." The concept of a qualified person can be traced back to the 1897 edition, which required a "competent man" to be on duty where generators were present. The term "competent man" was not defined.
A definition for "qualified person" followed in subsequent editions of the NEC, remaining essentially unchanged until the publication of the 2002 edition, when the bar was raised from simply being "familiar" with the construction, operation, and hazards associated with electrical equipment to having specific skills, knowledge, and safety training.
The current edition of the NEC defines a qualified person as "one who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved." This term is used throughout the NEC and is, in many cases, a condition under which a safe alternative approach to the operation of the system or equipment is acceptable.
This recent revision to the NEC’s definition puts it in step with the safety training objectives identified in Section 110.6 of NFPA 70E, which specify the level and type of training a person must have to be qualified.
In NFPA 70E, the primary approach to working on electrical equipment and systems is to place energized electrical conductors and circuit parts to which employees might be exposed in an electrically safe work condition before personnel enter the limited approach boundary. One way to establish an electrically safe work condition is to apply the appropriate lockout/tagout devices to energy sources. To facilitate implementation of the lockout/tagout procedure, a number of requirements regarding equipment "capable of being locked in the open position" have been added to, or revised in, recent editions of the NEC. Included is a requirement specifying that "the provision for locking or adding a lock to the disconnecting means shall be installed on or at the switch or circuit breaker used as the disconnecting means and shall remain in place with or without the lock installed." This requirement precludes having to employ portable or transferrable lockout devices.
Another provision added to the 2002 edition of the NEC is the arc-flash warning label required by Section 110.16 of NFPA 70E. The warning label, which is required for specified types of electrical equipment installed in other-than-dwelling occupancies, provides a warning of the potential for an arc-flash hazard. It must be visible to personnel before they examine, service, maintain, or adjust the electrical equipment. One of the Fine Print Notes that accompanies this requirement points the user to NFPA 70E for more information on the severity of arc-flash hazards, planning safe work practices, and selecting appropriate personal protective equipment (PPE).
It should be noted that Section 130.3(C) in the 2009 edition of NFPA 70E calls for equipment-specific information on available incident energy levels or the required level of PPE to be field-marked.
There is a clear delineation of scope between the NEC and NFPA 70E, but these and other recent changes in the NEC illustrate that there is an important relationship between the two documents and that some NEC requirements have a singular function of protecting only personnel working on energized electrical conductors or circuit parts. The continuing evolution of electrical safety for personnel is an interrelated mission of these two important documents.
Jeffrey Sargent is NFPA’s senior electrical specialist and is staff liaison for NFPA 70E.