This device belongs to the Vigilohm range designed to monitor ungrounded/IT electrical networks, in accordance to installation and products standards. According to IEC standards, it is mandatory to equip IT medical premises with Insulation Monitoring Devices (IMD). This device is dedicated to monitoring AC, DC and ACDC medical IT systems. It mesures the system insulation resistance by injecting a low frequency AC current between the network and ground. Configuration will be set in accordance to medical standards, from the front of the device, through the HMI screen. Setting are related to insulation alarm thresholds from 50 kilohms to 500 kilohms, and Transformer overheat and overload alarms. It monitors networks up to 230VAC, 230VDC, in medical IT architecture, and well as the medical IT transformer. The black and white screen can displays insulation resistance from 100 ohms to 10 megohms. Auto-test starts automatically every 5 hours, and on demand. 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 within 4 seconds. Once no fault is monitored, the alarm is cleared, the alarm relay is back to normal. The device can be supplied by a 110VAC to 230VAC source or a 125VDC to 250VDC, all with a tolérence of plus or minus 15%. This product can be installed on DIN rail, or flush mounted. Front face ingress protection is IP52, rear IP20 and overvolage category III. The monitoring device is equipped with a RS485 communication port, Modbus protocol.