FW851 Isolator Module

The FW851 isolator module protects the signaling line circuit (SLC) or data communication link (DCL) by isolating short circuit points. When a short trouble is detected, the internal relay triggers to cut power at the fault location, with the device's yellow LED indicating trouble condition by turning steady on. Upon return to normal condition, the internal relay restores to normal position to restore line power and the LED indicator turns off, maintaining system integrity throughout the circuit. The FW851 does not occupy an address on the fire alarm control panel's SLC/DCL, requiring no address programming and allowing maximum use of available device capacity. UL/ULC listed according to UL864 and ULC-S527 for fire protective signaling systems and indoor use, the module operates on 24 VDC nominal voltage (15-28 VDC range) with 1.6mA standby current and 10.8mA active current. The isolator mounts in FW800/FW801 surface boxes or flush-mounts on 4x4 inch electrical boxes, accommodating 12-18 AWG wiring. Measuring 120mm x 120mm x 45mm and weighing 8.8 oz with backbox, the isolator operates reliably in temperatures from 32°F to 120°F and humidity from 0% to 93% RH, providing critical circuit protection for Class A and Class B wiring configurations.