The FW851 isolator module isolates the short point on the signaling line circuit (SLC). The internal relay will be triggered to cut down the line power where the short trouble is detected. The device LED will indicate the trouble condition by yellow steady on.
A return to normal condition will cause the internal relay to normal position to restore the line power and the device LED indicator will return to the idle condition. The FW851 does not occupy an address on the Fire Alarm Control Panel’s SLC, so no address programming is required. The FW851 is a UL listed product according to UL864 and ULC-S527 for Fire Protective Signaling Systems for indoor use.
Enquiry about FW851 Isolation Module