The SD500-LIM is a line isolation module that acts as an automatic switch that opens when the line voltage on the signaling line circuit (SLC) loop is shorted. The SD500-LIM mounts in a standard dual gang or 4” square electrical box. The SD500-LIM Line Isolator Module is compatible with Honeywell Silent Knight FACPs. The SD500-LIM can be used on Style 7 (Class A), and Style 4 (Class B) wiring configurations. The SD500-LIM can Isolate a short circuit wiring fault on a SLC loop. Normally if a short on the SLC loop occurs, communication on the loop can be disrupted When isolator modules are used and a short occurs on the SLC loop, it will be detected as a trouble but all the SLC devices that are protected by a line isolator module will continue to operate.