Insulation monitor

Insulation monitoring devices (IMD) are used in unearthed networks (IT networks). The insulation resistance of the network to be monitored is measured against earth. These networks are protected by means of insulation monitors, the use of which is prescribed by law in IT networks by the standard "Safety of Machinery" DIN EN 60204-1 or DIN VDE 0100-410.

Insulation monitors serve to prevent accidents in the event of insulation faults, to prevent failures and generally to protect against fire and accidents. Residual current monitors are used for insulation monitoring in earthed systems.