This proposed standard had been returned to the Technical Committee for further study at the NFPA Fall Meeting in November, 1993. After the meeting, the proponents of the new standard tried to persuade the NFPA Standards Council to overturn the Association action and issue it anyway. They claimed the floor action was the result of serious distortions of the record by opponents of the new technology. They noted the financial interests involved in the higher costs of conventional systems, and alleged that these were a principal motivating factor behind the opposition. They implicitly threatened NFPA and others with a lawsuit based on the restraint of trade aspects of the process.
The Council disagreed, concluding the vote was sincerely motivated by concerns that the technology had not been proven. The Council decided to facilitate an independent third-party review and to defer further processing until then.
That third-party review was conducted by the National Institute of Standards and Technology (NIST), and resulted in a report issued in April of this year entitled "Early Streamer Emission Air Terminals Lightning Protection Systems: Literature Review and Technical Analysis." It concluded that "enhancement of upward streamer initiation from an ESE terminal (compared to a conventional terminal) has a plausible physical basis." The report also noted, however, that "the precise amount by which this enhancement in streamer initiation improves the lightning attraction efficiency of an air terminal remains questionable. There is reason to doubt that it significantly extends the maximum range of protection."
The NIST report concluded that "until issues concerning the relative performances of single ESE and conventional terminals are settled, meaningful statements cannot be made about the comparative performances of arrays of these terminals." Since there was little reliable evidence that the new terminals actually have an increased zone of protection, the Council decided that "a sound technical basis for proposed NFPA 781 has not been demonstrated."
The Council did agree, however, with another part of the NIST report that properly designed ESE terminals perform at least as well as conventional terminals with the same geometrical configuration. Therefore, these terminals may have a place in conventional lightning protective systems. The Council noted that nothing in NFPA 780 (Lightning Protection Code) prohibits such terminals if they otherwise comply with that standard.
The Council then considered whether the new standard should remain under further development and over two dissenting votes (Nelson and Peterson) decided that adequate research on these systems would not be available in the short term. The Council discharged the Technical Committee "with appreciation for their efforts." They noted that proponents of the new technology remain free to petition the Council "whenever they believe that the case can be made that the technology has been sufficiently validated to permit meaningful standards development."
In a related, parallel action, the Council rejected a complaint from ESE proponents suggesting that the conventional standard, NFPA 780 (Lightning Protection Code) be withdrawn since it could not be scientifically proven either. The Council noted the strong consensus that standard (which originated in 1904) had received in the current cycle. The Council did agree, however, to reidentify this document as a standard instead of a code, the "Standard for the Installation of Lightning Protective Systems," and to expedite the next review process by placing it on a two-year cycle (reporting to the 1997 Annual Meeting) instead of its normal three-year cycle.
MV tables fixed
NFPA has noted that the NEC ampacity tables for medium voltage conductors (Tables 310-67 through 310-84) were printed incorrectly in the first printings of the 1996 NEC. The tables as printed failed to take into account the panel action to accept additional 105 [degrees] C ampacity values in the form of additional columns in all of the ampacity tables.
The new values can be used "where design conditions require maximum conductor operating temperatures above 90 [degrees] C." This could be, for example, where the cable is buried deeper than the maximum depths allowed in Figure 310-1 and must be derated 6% per ft of increased depth. The higher value cannot be used for terminations unless the terminations have been listed accordingly.