System Sensor M500X


Fault Isolator Module

Availability: Please Call for Availability

  • Factory New
Brand: System Sensor Part #: L02C-9994 Categories: , Manufacturer Part #: M500X


The M500X Fault Isolator modules enable part of the communications signaling line circuit to continue operating when a short circuit occurs. The System Sensor M500X Isolator Module is an automatic switch that opens when the line voltage drops below four volts. This module is rigorously designed and tested for electromagnetic compatibility and environmental reliability, in many cases exceeding industry standards.

When installing Isolator Modules, the modules should be spaced between groups of sensors or modules in a signaling line circuit to protect the remainder of the signaling line circuit. If a short occurs between any two isolators, then both isolators immediately switch to an open circuit state and isolate the devices between them. The remaining units on the signaling line circuit continue to operate. No more than 20 devices are recommended for each group.

An LED indicator flashes in the normal condition and lights during a short circuit condition. When the short circuit is removed, the module will automatically restore the entire signaling line circuit.


Weight 0.4 lbs
Dimensions 0.25 × 4.00 × 4.25 in



System Sensor



Unit of Measurement

EA (Each)

Production Status




  • SEMS screws for easing wiring
  • Panel controlled status LED (except M501M)
  • Analog communications
  • Rotary address switches (except M500X)
  • Low standby current
  • Mounts in standard 4 ̋ junction box

500 Series Intelligent Modules

System Sensor - Data Sheet

M500X Fault Isolator Module

System Sensor - Installation and Maintenance Instructions