The CR/CF single circuit with normally closed contact configuration is available in Aluminum and White finish.  The suffix "W" denotes the White finish of the units.This heat detector, being Normally Closed, is often used in conjunction with household intrusion alarm panels, connected to a 24-hour input as an initiating device.  The internal contacts will open when the detector operates either on a rate of temperature increase, or if the releasing temperature is reached.  With its non-metallic diaphragm, the detector can operate normally at low temperatures, making it suitable for non-heated or chilled environments including garages and carports.  Because it responds to a rate of temperature increase, it is recommended that it be used in conjunction with sprinkler devices as the detector will initiate and alarm before the waterflow switch.


Combination Rate-of-Rise & Fixed Temperature

The Model Number prefix “CR” indicates that the detector is a combination Rate-of-Rise and Fixed Temperature,(often referred to as “Dual-action”), unit.  The Rate-of-Rise function allows the detector to open its contacts when the temperature at the ceiling increases at a rate of 8.4 Celsius degrees (15 Fahrenheit degrees) per minute. The opening of the contacts can initiate a fire alarm condition. The Fixed Temperature portion consists of a spring-loaded plunger held in place by a eutectic solder that will fuse at the specific temperature (in Fahrenheit degrees) as indicated by the Model Number i.e. 135,165, and 200 degrees.
Fixed Temperature Only
The Model Number prefix “CF” indicates that the detector is Fixed Temperature Only, and will therefore not respond to a rate of temperature increase but will operate when the detector fuses at the prescribed (Fahrenheit) temperature as indicated by the model number, i.e. 135,165, and 200 degrees.  This detector is referred to as “Fixed Temperature Only, non-restorable”.