4-Wire Photoelectric Detector w/Remote Alarm/Trouble LED, 12/24VDC, Not Listed FM, 741U w/702U Base. The TS7 Series features photoelectric smoke detectors with an easy to install and maintain head and terminal base design. The TS7 Series offers 2 and 4-wire models with optional fixed/ rate-of-rise heat detection remote LEDs, and an auxiliary relay for commercial applications, such as elevator recall. The TS7 Series includes both the head and SEMS terminal base eliminating the need to order the base separately. Orders are shipped with the appropriate six-inch base to support either two- or four- wire TS7 Series smoke detector heads.
The photoelectric smoke detector heads are self diagnostic and have field replacable optical chambers. They feature automatic drift compensation which adjusts the sensitivity if the detector becomes dirty over time, greatly reducing the chance of a nuisance alarm. If the TS7 ever does drift out of its UL Listed sensitivity range or fails internal diagnostics, the alarm LED flashes once a second to indicate trouble.