Device for determining the insulation resistance of a high-voltage battery system

The device has a high-voltage battery (HV-bat) and a high-voltage component (HV-komp), for example in the form of an inverter, where the high-voltage component is connected with the battery terminals over a switchable sliding valve (S-main plus,S-main minus). A reference resistor (R-0) is provided with a voltage measuring device for detecting the voltage applied between the respective pole and the reference potential of the vehicle body. The reference resistor is selectively switchable at the pole of the high-voltage battery via a switch (S-iso plus,S-iso minus,S-aux).