A rack PDU (power distribution unit) takes one input from your UPS or a wall circuit and spreads it across the equipment in a rack. Choosing one comes down to four questions: what power feeds it, how many and which outlets you need, where it mounts, and how much you want to see and control.
1. Match the input to the power that feeds it
Check the PDU's input plug, voltage and current rating against the outlet it plugs into. When the PDU is fed by a UPS, the PDU plug must match a UPS output receptacle (for example an L5-30P plug needs an L5-30R receptacle on the UPS). Rack PDUs range from 100 V single-phase to 240/415 V three-phase and from 10 A to 120 A [1], so confirm the phase and the circuit rating with your electrician before ordering.
2. Count the outlets, and check their type
List every device, its plug and its power draw. Most IT equipment uses IEC C13 (smaller servers, switches) or C19 (larger servers, blade chassis) inlets [1]; some devices use NEMA 5-15 or 5-20 plugs. Leave spare outlets for growth, and keep the total load within the PDU's rating.
3. Choose the mounting
Horizontal PDUs take 1U or 2U of rack space and usually carry 8 to 16 outlets; vertical (0U) PDUs mount at the back or side of the rack, do not use equipment space and can hold up to 54 outlets [1]. Check the rack's depth and rear clearance for a vertical unit.
4. Decide how much you need to see and control
- Basic: distributes power, no metering.
- Metered: shows the load on a local display, useful when you add equipment [1].
- Monitored: reports power remotely over the network, with alarms on thresholds you set [1][2].
- Switched: adds remote on, off and reboot at each outlet, and power-up sequencing [1][2].
Not sure which one fits?
Send us the UPS model (or the circuit), the list of devices with their plugs, and the rack model. We will confirm the matching PDU before you order. Browse rack PDUs.
Sources: [1] Vertiv, "What is a rack PDU" (vertiv.com, read 2026-09-29). [2] APC NetShelter Switched and Metered-by-Outlet rack PDU range pages (apc.com, read 2026-09-29).