Role of NEMA, including Standard Publication No. LS1
National Electrical Manufacturers Association (NEMA) may be best known for LS-1, but also serves as a collective mouthpiece for TVSS manufacturers relating to other Standards such as UL 1449, IEEE C62 series, IEC 61643 series, UL 96A Master Label, NFPA 780, etc. There is rarely a surge related Standard issued without NEMA member involvement.
NEMAsurge also maintains a substantial website for the NEMA Surge Protection Institute at: www.nemasurge.com.
In 1992, NEMA released LS1. To paraphrase the Scope and Forward, the document addresses a uniform specification of low voltage surge protective devices specifically manufactured for use in the low voltage transient surge environment. The intent of the document is to outline those surge protective device “parameters considered essential, and above all measurable, using current off the shelf testing equipment and referencing established standards and measurement guidelines…” This document does “not introduce new standards, derive test and evaluation methodology, or define extensive vocabulary.” LS1 references methods associated with measurement and derivation, but most are cursor">more readily addressed in available in ANSI, IEEE, and other technical publications. Section 2 identifies Specification Parameters. Section 3 notes Test and Evaluation Procedures from applicable testing Standards. The Appendix is the actual Specification Format form page.
LS1 became controversial when it began being mischaracterized as a testing standard having an implied requirement for independent testing. Various NEMA members felt this was being exploited for commercial advantage because LS1 is a Specification Format, not a test standard. NEMA does not sanction or qualify testing. LS1 was reaffirmed in 2000 due to its high visibility and acceptance. However, in May 2001, a NEMA Task Force convened to address “numerous cases of misuse” and “update it based on current experience and knowledge”.
LS1 is in Revision now, and expected to be released in 2007/2008. Please see APT document Eureka! – Upcoming Surge Standard Interrelationships explaining the near term future of LS1 and how it fits with other future Standards in a clear concise manner.