scope:

This manual, developed by NEMA's Fire, Life Safety, Security and Emergency Communications Section, provides technical information on basic fire alarm systems with a focus on early warning smoke detection devices. This document covers smoke detectors connected to a control panel and listed as complying with UL 268. This manual does not cover smoke alarms listed as complying with UL 217.

Purpose

The purpose of this guide is to provide information concerning the proper application of smoke detectors used in conjunction with fire alarm systems. It outlines basic principles, which should be considered in the application of early warning fire and smoke detection devices. Operating characteristics of detectors and environmental factors, which may aid, delay, or prevent their operation, are presented.

The intent of this guide is to provide educational material for fire protection engineers, mechanical and electrical engineers, fire service personnel, fire alarm designers, and installers.

Though this information is based upon industry expertise and many years of experience, it is intended to be used only as a technical guide. The requirements of applicable codes and standards, as well as directives of the Authorities Having Jurisdiction (AHJs), should be followed. In particular, NFPA 72 for installation of detectors and for testing of systems is a key element for the effectiveness of smoke detection systems.