This device belongs to the Vigilohm series, which is designed for monitoring ungrounded power supplies (IT systems) in accordance with installation and product standards. According to the standards, it is recommended to equip your systems with insulation monitoring devices (IMD). This device is intended for monitoring large and disturbed AC, DC, and ACDC systems. It measures the network insulation resistance by injecting a low-frequency alternating current between the network and ground. The configuration is set depending on the installation. Settings are made on the front of the device, via the HMI screen, or through the communication port. The settings relate to the network type, alarm and pre-alarm thresholds, alarm delay from 0 to 7200 seconds, and others are available. It monitors networks up to 830 VAC when connected to the neutral conductor, 480 V when connected to the line, and 480 VDC, with up to 500 microfarads. The black-and-white screen can display insulation resistance from 10 ohms to 10 megaohms, capacitance, and temporary faults. The autotest starts automatically every 5 hours and as needed. If the insulation resistance of the system falls below the set threshold, meaning there is a ground fault, an alarm is triggered via the IMD output relay. Once no fault is detected, the alarm is cleared, and the alarm relay returns to its normal state. The device can be powered from a 110 VAC to 440 VAC source or a 110 VDC to 440 VDC source, all with a tolerance of plus or minus 15%. This product is flush-mounted, for example, in a control cabinet door. The front protection rating is IP5, the rear protection rating is IP20, and the overvoltage category is 300 V Category III. The monitoring device is equipped with an RS485 communication interface with Modbus protocol.