Abstract: The present disclosure is directed to a rack power distribution unit (RPDU) that automatically and safely switches power to one or more receptacles. The RPDU includes one or more processors utilizing control algorithms that manage bistable relays so that in-rush current is minimized upon manual connection/disconnection of power to a load device. In particular, relay contact status (open/closed) is identified based on changes in RMS or peak voltage influenced by the load impedance. The RPDU is also configured to predict timings for voltage zero-crossing events. In this manner, and based on the determination of relay contact status and voltage zero-crossing prediction, open relay contacts are identified and safely closed at voltage zero-crossing.