The FW851 is a UL listed product according to UL864 and ULC-S527 for Fire Protective Signaling Systems for indoor use.

The FW851 isolator module isolates the short circuit point on the addressable loop (ALU). The internal relay will be triggered to cut down the line power where the short trouble is detected.

The FW851 does not occupy an address on the Fire Alarm Control Panel’s ALU.

The device LED will indicate the trouble condition by yellow steady on. When the trouble is cleared, the internal relay will restore the power line and the device’s LED will indicate normal operation.

• Voltage Range: 15 to 28VDC

• Operating Temperature: 32°F to 120°F (0°C to 49°C)

• Operating Humidity: 0% to 93% RH

• Mounting: FW800 Base