LOCATION OF DETECTORS

TM 10-6665-297-13&P 2-1 LOCATION OF DETECTORS 5. Corrosive gases: The destructive effects of corrosive gases may in some cases be minimized by locating the detector in a protected area and conditioning samples to reduce corrosiveness as they are drawn by vacuum to the detectors. Where moisture or liquid-type line filters are used, special care should be taken during installation to ensure that such devices are accessible for periodic servicing if required. 6. Water, moisture, dust, and dirt: Detectors should be mounted where water cannot enter and fill the housing to prevent exposure of the sensor element to air. Likewise, exposure to moisture, dust, and dirt should be minimized by locating detectors away from points where large amounts of such contaminants fill the air. Small overhanging or surrounding covers may be devised to protect detectors from the intrusions of dust and dirt in severe environments. A special moisture-proof detector (Model #0023-7317) should be installed where extreme humidity presents a special problem. 2-2 LOCATION OF CONTROL UNITS If possible, locate control modules or enclosures in dry, clean, nonhazardous areas; ideally, in plant engineer's control room or other place where temperature, moisture, corrosive and explosive atmospheres, or other conditions will not endanger personnel or hinder the maintenance and operation of the equipment. If a source of compressed air is readily available for cabinet purging, W- series (wall-mount) enclosures may be located in Division 2 hazardous locations. * The CD800X (explosion- proof housing) may be safely located in Division 1, Groups B, C, and D, hazardous environments. In any case, length of wire should be considered with respect to installation cost. If fans, sprinklers, door closers, ovens, or other devices are to be controlled by the control module relays, the length of the control wiring for these purposes should also be considered. 2-3 LOCATION OF WARNING DEVICES Remote annunciators such as bells, buzzers, lamps, etc., should be located where they may be readily seen or heard by personnel responsible for remedial actions, and preferably should be near the control cabinet where the nature of the condition and the appropriate response may be more readily perceived. Alarm devices should also be located in or near detectors to alert all personnel in the vicinity of an alarm. Audible alarms should be installed not less than one foot from the ceiling and, wherever possible, not less than eight feet from the floor. 2-4 CONTROL MODULE INSTALLATION Control modules and control module assemblies are installed in accordance with � Where permitted by governing code enforcement authorities. 23-9617 7/1/76 2-4