Rack PDU

Overview

A rack PDU is the strip that turns one feed from the data-centre busway into many protected outlets for the servers in a rack, while measuring how much each one draws and letting an operator switch any outlet on or off from across the world. This unit is the switched-and-metered-by-outlet class, the most capable type, so capacity planning, stranded-power reclamation, and remote rebooting of a hung server all become possible without anyone walking to the cage. It mounts vertically in the zero-U channel at the back of the rack, out of the way of the equipment airflow.

How it works

Power enters through the Input Section: a fixed Input Cord feeds a Main Breaker that protects the whole strip and serves as the local isolator, after which current flows onto the internal busbar. The Output Section runs that busbar the length of the chassis and taps off a row of locking IEC Outlet receptacles, mixing C13 and higher-current C19 sockets.

Between the busbar and each outlet sits the Metering Board. For every outlet it carries a switching Relay and a current shunt, and a microcontroller reads voltage and the shunt drop to compute current, power, and accumulated energy at billing-grade accuracy. The Network Module gathers those readings, presents them on its LCD Panel, and exposes them over Ethernet through SNMP and a web interface, where the same channel commands the per-outlet relays for remote switching.

Incoming transients are clamped by the Surge Protective Device device before they reach connected gear. The whole assembly is built into an extruded Chassis that doubles as a heatsink, and the Mounting Hardware hardware clips it toollessly to the rack frame.