This device belongs to the Vigilohm range designed for the monitoring of unearthed 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 the monitoring of 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 earth. The configuration is set depending on the installation. The settings are made on the front of the device, from the HMI screen or from the communication port. The settings refer to the network type, the alarm and pre-alarm thresholds, the alarm delay from 0 to 7200 seconds and others are available. It monitors networks up to 830VAC when connected to the neutral, 480V when connected to the line and 480VDC, with up to 500microfarad. The black and white screen can display insulation resistance from 10 ohms to 10 megohms, capacitance and temporary faults. Autotest starts automatically every 5 hours and when required. If the insulation resistance of the system falls below the set threshold, i.e. there is an earth fault, an alarm is triggered via the IMD output relay. Once no more faults are detected, the alarm is cleared and the alarm relay returns to normal. The device can be powered from a 110VAC to 440VAC source or a 110VDC to 440VDC source, all with a tolerance of plus or minus 15%. This product is flush mounted, e.g. in a control cabinet door. Front protection class is IP5, rear protection class IP20 and overvoltage 300V category III. The monitoring device is equipped with an RS485 communication interface with Modbus protocol.