Insulation resistance measurement for inverters

An inverter, comprising:

• a first ungrounded terminal and a second ungrounded terminal, between which a DC link voltage is present in operation of the inverter;
• at least one half-bridge connected between the first and second ungrounded terminals, and having two active switching elements for driving an output current and a center point positioned between the two active switching elements;
• and
• an apparatus for measuring an insulation resistance of an input source associated with the inverter, wherein the apparatus comprises a grounding switch configured to connect the center point of the half-bridge to a grounding point, and wherein the apparatus is configured to connect the center point connected to the grounding point, one after the other, to the first and second ungrounded terminals by means of the two active switching elements of the half-bridge, respectively, to establish a connection between the first and second ungrounded terminals and the grounding point, and wherein the apparatus is configured to measure a current flowing via the connection to the grounding point using a measuring device.