The TD-135 is a conventional fixed-temperature heat detector engineered to provide thermal fire detection in a low-profile design. Built with a neutral white, fire-resistant thermoplastic housing, it blends into room ceilings while protruding no more than one inch below the surface. Equipped with a bi-metal disc sensing element, the unit automatically initiates an alarm by closing its normally open contacts when ambient temperatures exceed 57°C. The detector automatically resets and returns to normal operation once ambient air temperatures drop back below the rated threshold.
