Single-phase and three-phase smart PDU meters are based on the innovative SUM (sustainable, scalable and maintainable) design concept technology. As a key component of the metering cabinet power distribution unit (PDU), after being installed into the main body of the PDU, it can Provides active metering capabilities for energy optimization and circuit protection. User-set alarm thresholds can effectively reduce risks by warning of potential circuit overloads through real-time local and remote alarms. Metered rack PDUs provide power usage data to support data center managers in making informed decisions about load balancing and proper IT sizing, thereby significantly reducing total cost of ownership. Users can configure metered cabinet PDU via Ethernet access or RS485. This series of products can be widely used in data center rooms such as IDC, banks, securities, governments, and enterprises.