Virtualization, cloud computing, and the never-ending drive for peak operating efficiency are changing the ways companies design and run data centers. In the process, they’re also changing the capabilities that organizations require for power distribution and how its growing importance is shaping today’s data center facilities.

For enterprise and multi-tenant data centers alike, the ability to stay up and running requires advanced rack power distribution units (PDUs) that can precisely monitor every aspect of power and enable the management of power distribution. Without advanced rack power distribution technologies, data centers are at risk of being unable to keep up with the ever-expanding needs of today’s business requirements.


The modern data center is under intense pressure on many fronts. While information is increasingly important to organizations in all industries as demonstrated by the exponential growth in data volume, data center operating budgets aren’t keeping pace. With more demands and stagnant budgets, data centers must operate efficiently even as profit margins tighten. As a result, they face the dual task of operating with energy efficiency and reducing downtime as much as possible.

At the same time, virtualization is creating a heightened need for agility throughout the data center. This agility mandate is further reinforced by the rising use of cloud-based solutions and co-located data centers, which in turn is driving the need for higher accuracy in billing — often down to the single outlet level in a rack. Data centers are also increasingly implementing converged infrastructure environments — pools of integrated storage, server, and networking technologies made possible by virtualization. With these environments, data centers are equipped to meet the on-demand computing challenges of today’s businesses, provided they can manage the fluctuating power distribution requirements that meeting such challenges entails.


The modern data center functions much like a utility, providing computing capacity in response to customer growth and changing consumer demand. While high-level power distribution strategies are needed to achieve peak efficiency, data centers must go beyond a big-picture view of operations.

Data center managers that are contending with a variety of pressure-inducing factors must keep a watchful eye on all aspects of power distribution at a granular level. Some of the latest advanced rack PDUs offer advanced monitoring and management capabilities that provide data centers with more comprehensive functionalities, such as:

 Keeping cooling costs down. Many data centers struggle to keep cooling costs down as density requirements increase. Modern hot-air containment solutions require higher rack PDU operating temperatures, so it’s important to select a PDU that has the ability to function at a high operating temperature to reduce overall costs.

 Environmental monitoring. Temperature monitoring can help data centers keep a lid on cooling costs by accurately identifying where heat and humidity are building in the data center, allowing operators to respond accordingly. Such environmental monitoring is particularly suited for containment or network closets, where excessive heat can create reliability issues. Additionally, as data centers take advantage of outside air cooling whenever possible to reduce costs, it becomes increasingly necessary to monitor temperature to mitigate heat and humidity concerns. Environmental monitoring can also include switch closure monitoring to connect door switches or water sensors.

• Increased efficiency. Efficiency can be enhanced by features on the rack PDU itself. The ability to set the IP address and serial or part numbers on a rack PDU with advanced pixel LCD display and interactive menu system enables data center staff to quickly configure four rack PDUs from a single IP address and network port. For data center staff, this facilitates the management of power suppliers on different feeds through a single interface. The ability to establish a daisy chain can reduce physical infrastructure installation costs by reducing the number of network ports. Network connected PDUs also offer capabilities that allow users to auto discover and monitor multiple ePDUs through virtualization platforms to avoid costly downtime.

• Reducing administrative costs. Given the budget and resource constraints faced by many data centers, administrative overhead is another critical area that requires constant diligence. Advanced rack PDUs that enable mass configuration and updating capabilities can free up data center staff to concentrate on more strategic tasks. Additionally, enhanced PDUs with a hot-swap network meter module allow users to replace the module without shutting down servers to maintain business continuity and enhance serviceability. Ensuring 1% billing grade accuracy is also an important factor for many of today’s colocation facilities. Providing the ability to measure power precisely at the outlet level, data center managers can hone in on their energy use and work out potential rebate opportunities with utilities.

• Easing installation. Ease of installation is more than just a convenience and time saver. Many advanced rack PDUs are easy to install thanks to features such as clip feet for variable mounting options; pre-installed, double-sided buttons that accommodate varying metal thickness; and side mounting button locations that facilitate 90-degree rotation in the rack.


Before selecting a rack PDU, data center managers should first take inventory of the technology needs of their data center and then determine the required power rating they will need in a PDU. When designing a data center, operators typically take into account the planned capacity of the rack to calculate power and cooling requirements. Rack capacity is then used to select the appropriate input plug for the rack PDU. Today’s data centers should select a PDU that is not only capable of carrying the full power load, but has excess capacity to accommodate future expansion.

Once the power rating of the PDU is considered, data center managers should next evaluate technologies when selecting a PDU. Typically, rack PDUs come in three categories: basic distribution, metered distribution, and managed or switched distribution.

Moving up the stack from basic to metered will give data centers the ability to locally measure current and load balance — not to mention the capability to remotely monitor branch circuits and facilitate capacity planning. With advanced meters, data centers gain the capability to meter power at the outlet level, which is the advanced functionality needed for accurate Level 3 PUE calculations. For example, outlet-level metering with Eaton’s ePDU G3 platform provides a level of granularity in reporting power usage that is often required to remotely cycle power in the rack. Combining this feature with outlet switching, data centers can also turn off outlets when not in use, thereby preventing accidental overloading of the rack PDU. Additionally, outlet switching enables data centers to sequence power up and perform load shedding, an important element of an overall power strategy.


On a high level, data centers can implement environmental technologies such as airflow management solutions, including aisle containment doors and ceilings, blanking panels, and data center cages for secure partitioning and enhanced efficiency. Data centers are also deploying uninterruptible power systems (UPSs) to improve efficiency and reduce power costs without compromising protection. Busways that offer multiple plug-in configurations can enable data centers to flexibly connect power to those server cabinets with the capacity to meet high power demands.

Power distribution can be further enhanced with the use of cables and accessories that can deliver outlet and section current information to improve both management and troubleshooting. With the addition of power management software, data centers can monitor operations to the outlet level, further optimizing operational efficiency. In conjunction with hardware and software solutions, data center managers can keep operations efficiently running by utilizing comprehensive services that include technical expertise for all products that are designed to improve costs, uptime, reliability, and power quality as well as an expansive, 24x7 support network.

As the computing demands of their customers continue to increase, however, data centers can no longer afford to examine power distribution purely at a high level. With virtualization and converged infrastructure, computing capacity is dynamic. Workloads, applications, and storage are moved around both within and among data centers as business needs dictate.

To ensure peak operating efficiency — an absolute necessity given modern business demands — data centers must monitor and manage power distribution at a granular level. Advanced rack PDUs have the features and reliability today’s data centers need to maintain their own operations, but more importantly to support the changing and accelerating demands of the business.