Tyco LIM800 Isolator Module with M520 Cover MX Minerva
The LIM800 is an MX Addressable Loop Isolator Module that can be used to provide short circuit isolation between zones or portions of the MX addressable loop. LIM800s are installed at appropriate positions around the MX loop to monitor the loop voltage either side of the device. If the voltage drops to zero volts (e.g. due to a short), the two LIM800s either side of the short open their electronic switches and isolate the shorted section allowing the rest of the loop to be driven by the MX Control and Indicating Equipment (c.i.e.).
The LIM800 includes an additional spur output that can be wired to additional MX devices (usually all in one zone). If a short occurs on the spur, the two electronic switches in the LIM800 operate and disconnect the shorted spur from the loop. The LIM800 includes a yellow LED to indicate when one of its connections is shorted. The LIM800 supports up to 100 IB units of MX load on each connection, so additional LIM800s can be installed on long sections of cable to isolate each block of devices.