The FW859 isolator module is designed for installations where disconnection or damage on a dwelling wiring will not interfere with the ability of the audible devices to affect other dwelling units to activate during an alarm. In this configuration, if a sound or sound/visual device in a dwelling has an open circuit or a short circuit, the control panel will indicate a zone problem.
The FW859 fits into a 4-square-inch square electric box. The FW859 provides two supervised isolator outlets (two dwellings) with a capacity of 200 mA per output. In this configuration, if the sound system has an open circuit, the control panel will indicate a zone problem.
It is a product ranked UL according to UL864 and ULC-S527 for fire protection signalling systems for indoor use.