Rack PDU — 1U and 0U, 16A/32A, C13/C19, Metered and Intelligent

A 1U horizontal PDU mounts in the 19-inch frame and usually has 6 to 8 C13 outlets. A 0U vertical PDU mounts at the rear and can carry 20 to 30 C13 outlets plus 4 to 6 C19 outlets. The vertical format saves rack space and is the standard for dense server cabinets.

Choose the format by outlet count and access. A small network cabinet with four switches may need only 8 outlets; a 42U server cabinet with 20 servers may need 24 to 30 outlets plus C19 for high-power equipment.

At 220–250 V, a 16 A PDU supplies about 3.5 kW and a 32 A PDU supplies about 7 kW. Apply a derating margin and confirm the upstream breaker and cable size. Do not run a PDU continuously at its full rating.

For a cabinet with 6 kW of IT load, two 32 A PDUs on separate feeds are common. For a network cabinet with 1 kW to 2 kW, one 16 A PDU is usually enough. For three-phase power, use a three-phase PDU or three single-phase PDUs on separate phases.

A basic PDU has a breaker and outlets. A metered PDU adds a local display for current, voltage and power. A monitored PDU adds SNMP or Modbus. A switched PDU adds outlet-level on/off and restart. For colocation and remote sites, switched PDUs reduce site visits.

Protection options include MCB or RCBO breakers, surge protective devices, over-temperature alarms and sequential start. Sequential start avoids the inrush current that can trip the upstream breaker after a power restore.

Mount a 1U PDU at the bottom or top of the cabinet and a 0U PDU on the rear side rail. Keep the input cable bend radius clear and the breaker accessible. Label every outlet and cable, and keep power cables away from data cables.

For redundant equipment, connect dual-corded devices to A and B PDUs. Use outlet-level metering to balance the load and identify hot spots. Confirm the plug type and the local electrical code before ordering.