MIL-PRF-32227

Abstract

This specification covers the performance requirements for Flame Detector Zone Modules (FDZM) (see 6.8.6), Switch Closure Zone Modules (SCZM) (see 6.8.16), and isolators (see 6.8.9) and their respective enclosures, which are components of an overall Advanced Fire and Smoke Sensor System (AFSSS) for use on naval ships. These devices may be of commercial-off-the-shelf (COTS) design, but must be rugged (see 6.8.13) enough to meet all of the requirements of this performance specification and the rigors of Navy shipboard service. Performance requirements for the other associated AFSSS components (e.g., ionization (see 6.8.8) and photoelectric (see 6.8.10) smoke sensors (see 6.8.15), heat sensors (see 6.8.7), flame detectors (see 6.8.5), and alarm panel (see 6.8.2)) are contained in their respective AFSSS specifications.<b><u>Intended Use:</u></b> The FDZM is intended to interface one AFSSS flame detector with the AFSSS alarm panel for power and monitoring purposes. If AFSSS flame detectors are actually equipped to be powered and monitored directly on the AFSSS (multiplexed) sensor loop, then FDZMs are not required and can be ignored throughout this specification. This specification, however, assumes that the AFSSS flame detectors are not equipped to be powered and monitored directly on the AFSSS sensor loop. (The AFSSS ionization and photoelectric smoke and heat sensors are so equipped.) Thus, FDZMs are assumed to be required to provide the individually addressable flame detector alarm signal to the alarm panel and to connect appropriate power from the alarm panel to the flame detector for operation via separate cabling (i.e., a separate power cable is used, different from the sensor loop cabling). The SCZM is intended to interface an individual switch closure device that does not require power (e.g., a water flow switch, manual pull station, water switch, and flooding switch) with the AFSSS alarm panel for monitoring purposes. Isolators are intended to protect sections of AFSSS alarm panel sensor loops from short circuits. Isolators are placed in series on the sensor loops, where they monitor for short circuits. Isolators are installed after groups of heat and smoke sensors, FDZMs and flame detectors, and SCZMs depending on the degree of overall sensor loop survivability desired. In the event of a short circuit, two isolators open, removing the shorted section of cabling from the sensor loop. The sensors, detectors, and zone modules remaining on both isolated sections of the sensor loop will continue to operate and communicate with the AFSSS alarm panel. The sensors, detectors, and zone modules located between the isolators (within the shorted section of cabling) will not be powered or operational. FDZMs, SCZMs, and isolators are three of several types of devices, detectors, or sensors used in the AFSSS and intended for use on Navy ships.<br>