The Schneider Electric Iso-gard MLHG6 Line Isolation and Overload Monitor (LIOM) measures electrical supplies in critical health care applications such as operating theatres and intensive care units.

Monitoring the total hazard current (THC) in an isolated AC system, the MLHG6 LIOM alerts personnel when the THC exceeds the LIOM setting of five-milliamps.

The Schneider Electric MLHG6 displays the THC on the seven segment display and the LED bar graph. In the normal condition, the green “SAFE” LED is illuminated, the display shows a low leakage value (green) and the bar graph is in the non-alarm, or normal, green zone. THC levels will increase as additional loads are connected to the system, and/or when a line-to-ground fault has occurred. If an alarm condition is triggered, then the red “HAZARD” LED will be illuminated and the audible alarm will sound. The audible alarm may be silenced by pushing the “MUTE” button. After the fault is removed, the LIOM will automatically reset to the normal condition.

The MLHG6 also features an optional remote display unit for easy access to information in applications such as pendants or in larger critical care units. The MLHG6 can also be integrated into building management systems through an optional Modbus interface.

Standards compliance

The Schneider Electric MLHG6 LIOM complies with AS/NZS4510:1999 Isolated Electrical Supply Systems for Medical Applications and can be used to fulfill the requirements of isolated power supplies under AS/NZS3003:2011 Electrical Installations – Patient Areas.