The 5151 Heat Detector is a combination of a fixed and rate-of-rise thermal detector. It communicates an alarm to the central control panel prior to reaching its fixed set point for high rates of rise, providing a timely response to both rapid and slow temperature increases.
The 2-wire device provides open-area protection with 50-foot spacing capability as approved by UL 521. For local alarm indication, it includes two LEDs on each detector for full 360-degree visibility.