The insulation monitoring device (also called insulation monitor) constantly monitors the insulation resistance of IT systems (unearthed networks) and issues a message if it falls below a response value.
For measurement, the device is connected between the IT system and the protective conductor (PE). A measuring current is superimposed on the network, which is recorded and evaluated by a measuring circuit. With insulation monitoring devices, you can detect deteriorations in the insulation level early and safely.