This device belongs to the Vigilohm range designed to monitor ungrounded/IT electrical networks, in accordance to installation and products standards. According to standards, it is recommanded to equip your systems with Insulation Monitoring Devices (IMD). This device is dedicated to monitoring pure AC systems of limited size, with low disturbances. It mesures the system insulation resistance by injecting a DC current between the network and ground. Configuration will be set depending on the installation. Settings are available on the front of the device. Settings are alarm and pre-alarm thresholds. It is equipped with a manual auto-test. In case the system insulation resistance drops below the set threshold, meaning a ground fault occurred, an alarm is triggered thru the IMD output relay. Once no fault is monitored, the alarm is cleared, the alarm relay is back to normal. This product can be installed on DIN rail.