The BENDER IR470LY-40 is an insulation monitoring device (IMD) designed for AC, DC, and AC/DC IT systems (unearthed systems). It is suitable for universal applications, particularly in systems containing frequency converters, DC drives, UPS systems, or battery systems where both AC and DC components exist. This device continuously monitors the insulation resistance between the system conductors and earth, providing early indication of insulation faults. It utilizes Bender’s AMPPlus measurement principle, ensuring reliable monitoring even in complex systems with high leakage capacitances or varying voltage/frequency conditions. The IR470LY-40 features an LCD display for measured values and device parameters, along with configurable alarm relays for fault signaling.