This device belongs to the Vigilohm series, which was developed for the monitoring of ungrounded power supplies (IT systems) according to the installation and product standards. According to the standards, it is recommended to equip your systems with insulation monitoring devices (IMD). This equipment is suitable for monitoring of pure AC systems with limited size and low disturbances. It measures the line insulation resistance by feeding a DC current between the mains and the ground. The configuration depends on the installation. The settings are available on the front of the device. The settings apply to alarm and pre-alarm thresholds. It is equipped with a manual autotest. If the insulation resistance of the system falls below the set threshold value, i.e. if there is a ground fault, an alarm is triggered via the IMD output relay. As soon as no more faults are detected, the alarm is cleared and the alarm relay returns to its normal state. This product can be installed on a DIN rail.This text is machine translated.