The SST Model S250 Smoke Detector is a dual chamber ionization type detector designed to respond to the first traces of a fire by sensing both visible smoke and invisible products of combustion. A unique sensing chamber design insures maximum smoke response from any direction, even in air velocities up to 2000 feet per minute. It is designed for smoke detection in open areas or, when used with the optional duct housing, in air ducts. When installed with a suitable NOVA-5000 Detection System, the Model S250 may be used for Releasing Device Service.
The smoke detector is installed into its accessory base with a simple twist-lock action, which prevents unauthorized removal of the detector. Operating power is provided over the 2-wire detection circuit from the Control System. Proper operation of the detector is indicated by a blinking Light Emitting Diode (LED), which changes to a steady “on” condition when smoke is detected.