Power Distribution Units (rPDUs) are the last link in the power chain and ensure delivery of critical power to IT loads.
The rPDU does not generate power but rather distributes power from the power source available. In a typical data center environment, the rPDU is connected to an upstream Power Distribution Unit (PDU) commonly referred to as a floor PDU. The floor PDU distributes power from the utility during normal operation. During an outage, an uninterruptible power supply (UPS) picks up the power load while the generator ramps up to begin providing power to the facility. The floor PDU is similar to the circuit breaker panel in your home and breaks down the available power into circuits so electricity can be distributed throughout the facility. The generator is used for redundancy in case utility power is lost. Power is distributed through the facility from the floor PDU, and the rPDU is connected downstream. The rPDU then distributes power to the IT equipment in each individual cabinet and rack.
The rPDU is capable of monitoring, managing, and controlling power consumption to multiple devices in data center environments. It can distribute large amounts of electricity and can be accessed over the local network or remotely. To meet the ever-changing needs of the data center, rPDUs can accommodate higher power densities and are resistant to higher temperatures. To avoid compromising basic power distribution, some rPDUs are easily upgradeable and serviceable without the need to remove power from the connected devices. These features minimize downtime and carry manufacturer-provided support to meet Service-Level Agreements (SLAs).
When selecting your rPDU, begin with these basic questions:
- What are your power requirements?
- Do you want to mount your rPDU vertically or horizontally?
- What level of power monitoring or management do you require?
The most important question when selecting an rPDU is determining the power requirements needed for the critical IT equipment that will be connected. Depending on the data center, the data center manager may be limited to the power available. While in other situations, the data center manager may be able to dictate what power is delivered to the rack. If the data center manager has the ability to decide the power available, he or she should determine the approximate kW needed for the equipment that is or will be deployed. The power needed will provide the minimum power required for the equipment in the rack allowing the data center manager to appropriately determine the rPDU power configuration needed. The data center manager will then be able to have an electrician pull the necessary power with the appropriate receptacle to the rack that matches the rPDU.
On the other hand, if the data center manager is restricted to the power that is already available, he or she will need to identify the receptacle type the rPDU will need to plug into. Depending on the power available, the cabinet density could be limited or additional rPDUs will need to be deployed in the same cabinet to reach the power capacity required for the deployed equipment.