Line Isolation Monitors in Isolated Power Systems

The line isolation monitor is a critical component of an isolated power system. The line isolation monitor continuously monitors the isolated power system's impedance from all conductors to ground. Impedance includes both resistive and capacative readings. This value is then used to calculate the Total Hazard Current (THC), which dictates what current could flow if a patient were to come in contact with a conductor to ground. The THC reading provides advanced warning of isses that are present in the system.

Figure 1: Monitoring and notification capabilities of an isolated power system

Since the line isolation monitor is on an isolated power system, power interruption is not necessary and critical processes may continue to run. Continuity of power is maintained on systems where interruption cannot be tolerated. A single ground fault condition will also not trip the main circuit breaker. Appropriate actions may be taken while the system remains online.

Figure 2: The LIM2010 line isolation monitor in the alarm condition

The LIM2010 clearly displays the total hazard current on the face of the panel, as well as providing an audible alarm. Technical personnel may be notified immediately of an alarm condition with remote communication capabilities. Ground fault location capabilities are also available, providing notification of the source of the fault in a timely fashion.