NEMA LS 1

Description / Abstract: This document addresses a uniform specification of Low Voltage Surge Protective Devices (also called Transient Voltage Surge Suppression (TVSS) devices) specifically manufactured for use in the Low Voltage (Line Service Voltages of less than l000 VRMS) Transient Surge Environment.

This document consists of two sections:

1. Specification Introduction and Definitions--where specification parameters and their definitions are given.

2. Test and Evaluation Procedures--where the guides, standards, and methodology of determining specification parameter values are introduced.

In presenting a specification format, it is not the intent of this document or that of NEMA (LOW Voltage SPD Section) to introduce new standards, derive test and evaluation methodology, or define extensive vocabulary. Rather, those parameters considered essential, and above all measurable, using current, off-the-shelf test equipment and referencing established standards and measurement guidelines, are introduced as constituting the body of a proper specification format. The methods associated with their measure or derivation will be referenced, though most are not extensively addressed, since adequate procedurai definition and discussion is readily available in ANSI, IEEE, and other technical publications.

Above all, this document is intended to be general in nature. As such, some terms and procedures may not apply to certain devices. Others may require additional technical information in order to adequately define unique application capability or special characteristics. Therefore, specification format and reference to existing standards are emphasized.