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Detect-A-Fire Thermal Detectors can be used with Clarke's consoles or as a stand alone detector.When used with a console, an Interface Device is necessary to link the detector to the console.
DETECT-A-FIRE units are the heart of many Fire Protection Systems. These highly reliable devices have been a standard of the industry for over 45 years. In some systems the device is used as an ALARM device. to sense overheat or
fire, and alert personnel. In other systems, it is used as a RELEASE device, to sense fire and actuate fire attack systems.
DETECT-A-FIRE units have met with wide acceptance because they are designed with RATE COMPENSATION.
This provides a unique advantage over both fixed temperature and rate-of-rise types of detectors because only the DETECT-A-FIRE unit accurately senses the surrounding air temperature regardless of the fire growth rate. At
precisely the predetermined danger point, the system is activated.
Fixed temperature detectors must be completely heated to alarm temperature and therefore a disastrous lag in time may occur with a fast rate fire.
Rate-of-rise devices, on the other hand, are triggered by the rate of increase in ambient temperature and are subject to false alarms caused by harmless, transient thermal gradients such as the rush of warm air from process
ovens.
The secret of the unit's sensitivity is in the design. The outer shell is made of a rapidly expanding alloy which closely follows changes in surrounding air temperature. The inner struts are made of a lower expanding
alloy. Designed to resist thermal energy absorption and sealed inside the shell, the struts follow temperature changes more slowly.
A slow rate fire will heat the shell and struts together. At the "set point", the
unit will trigger, actuating the alarm or releasing the extinguishant.
A transient rush of warm air up to 40ºF /min. may expand the shell, but not enough to trigger the unit. By ignoring transient warm air excursions, the
DETECT-A-FIRE unit virtually eliminates false alarms prevalent with rate-of-rise devices.
If a fast rate fire starts, the shell will expand rapidly. The struts will close, actuating the alarm or releasing the agent. The
faster the fire rate of growth, the sooner the DETECT-A-FIRE unit will react.
Vertical detectors are designed for use in both "ordinary" or "harzardous" locations. For "ordinary" use, they may be mounted to any approved junction box with 7/8 inch diameter opening by using 1/2
14 NPT mounting nuts. The device may be wired in or out of conduit, depending on local preference and codes. Four leadwires are provided on normally open vertical units (that close on temperature rise), per UL requirement, to
facilitate supervision of system wiring.
Instruments are Underwriters Laboratory and Underwriters Laboratory of Canada listed and Factory Mutual approved for hazardous locations, when mounted in a suitable fitting.
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