NFPA 70E changes and signage requirements
Answered by Charles Helmick, development manager, AVO Training Institute, Dallas.
It should be noted that the only information for the 2012 NFPA 70E available at the time of this writing is in the Report on Proposals Draft and the public comments to those proposals. The 2012 edition of the 70E will not be available until fall 2011. That being said, the information available indicates that signage requirements will be more specific in the new 70E.
The NEC in Article 110.16 requires electrical equipment to be field marked to provide qualified employees with information they will need to work on the equipment and be able to protect themselves from arc flash hazards. Field-marked signage is integral to work procedures and has escaped the purging of installation requirements that is part of the revision to the 2012 edition of the 70E.
First, to address the term "field marked," it should be noted that manufacturers of electrical equipment do not have the necessary information to provide field-marked signage. Quite often the owner of electrical equipment (employer) is of the opinion that the equipment should be marked by the manufacturer. However, the manufacturer has no way of knowing what the short-circuit current or clearing time is that will be feeding each individual piece of equipment, and those are two main factors in determining the personal protective equipment required to work on that equipment.
Second, the manufacturer has no way of knowing the specific safe work procedures that will be required on a piece of equipment. For example, the manufacturer could put a sign on a piece of equipment stating there is an arc flash hazard present if the equipment door is open. The sign will soon be ignored because it does not address specific work procedures needed for opening the door.
The 2009 70E in 130.3(C) requires, as a minimum, the listing of the available incident energy or the required level of PPE. According to the 2012 70E, ROP 130.5(C), the same requirements are there, plus the sign should list the date the arc flash analysis was performed, the nominal system voltage and the arc flash boundary. Furthermore, the method of analysis must be documented and the ANSI Z535.4 listed in the Informational Note (formerly FPN) to provide guidelines for signage.
The 2009 70E requires a review of the analysis every five years, and the new signage requirement will make it easier for the employee using the signage information to know if the information is current or due for review.