6SE6440-2UD15-5AA1 MICROMASTER 440 Inverter Drive, 3-Phase In, 0 – 550Hz Out, 0.55 kW. The Siemens Micromaster 440 is an AC vector drive designed for automation applications that require broad functionality and dynamic response. The Micromaster 440 features an integrated brake chopper and has the ability to stop at a target position without an encoder.