The testing of power inverters for automotive applications increasingly includes testing at low temperatures of -40°C up to high temperatures of about 110°C. The test consists of a run-in process with high phase current at different temperatures. The temperature control comprises not only the circulating air temperature but also the temperature of the cooling liquid. The test bench is able to test two DUTs simultaneously and can be switched between high voltage and low voltage (48V) applications. The individually designed part fixtures are interchangeable. The temperature cycle test is usually carried out during series production.