Optimising power distribution: the importance of visibility


    EPE008407 - MaintenanceBy adopting a more holistic approach to infrastructure management, and in particular the monitoring and management of power distribution, IT and data centre managers can improve monitoring and maintenance across all applications, make better informed decisions and reduce costs. Scott Bailey, IT/DC segment manager for Eaton UK, explores the challenges and how rack-based power distribution unit technology can address some of the issues. 

    The successful management of a company’s facilities infrastructure, combined with its IT infrastructure (be that via a data centre or network closet) is now the foundation of successful business operations.

    Peak operating efficiency and reliability are, of course, necessities. Should the facility falter, the business suffers as a result and consequently these demands are changing the way companies view their infrastructure. There is a need now in many businesses to monitor every piece of power-drawing equipment and to do so in detail and with high accuracy.

    For both enterprise network closets and multi-tenant data centres, the ability to keep operating requires precise monitoring of every aspect of power, as well as effective management of power distribution. This is where advanced rack power distribution units can come in. Without them an IT infrastructure is at risk of being unable to keep up with ever-expanding requirements and demands.

    Functioning much like a utility, data centres provide computing capacity in response to demand. High-level power distribution strategies are needed for peak efficiency but businesses that are contending with a variety of pressure-inducing factors must keep an eye on all aspects of power distribution at a granular level too. The latest in advanced rack PDU technology offers devices with monitoring and management capabilities and comprehensive functionality that addresses the most pressing operational needs.

    Controlling cooling costs

    ePDUsFirstly, cooling costs have to be controlled as density increases. Modern hot-air containment solutions require higher rack PDU operating temperatures. Therefore, rack PDUs that have the ability to function at high operating temperatures, (60°C) UL and CE rated, can help reduce overall costs. Adding temperature monitoring can also control cost by accurately identifying where heat and humidity is building. This allows operators to respond accordingly.

    Such environmental monitoring is particularly suited for containment or network closets where excessive heat can create reliability issues. Additionally, as outside air is used more frequently to reduce cost, it becomes increasingly necessary to monitor temperature. Environmental tracking also includes switch closure monitoring to connect door switches or water sensors.

    Given budget and resource constraints, administrative overhead is another critical area that requires constant diligence. With operational staff stretched to the limit, rack PDUs that can help reduce this overhead are key in creating an efficient operation. Rack PDUs that enable mass configuration and updating capabilities free up staff to concentrate on more strategic tasks.

    In addition, rack PDUs with branch circuit colour-coding that match corresponding outlet sections can make it easy to know which branch circuit breaker connects to which specific outlet. This can reduce the time spent troubleshooting the source of problems and can simplify load balancing.

    Other features that can keep costs down include a low-profile form factor. It is also worth looking for rack PDUs with low-profile circuit breakers or the ones that are width-optimised for side mounting. This prevents interference with the rail that can block hot-swap fans and power supplies and minimises the time required to service the rack in the event of component failure.EPE008407 - Technician

    Creating agility

    When it comes to creating agility, one of the best ways to do this is to ensure a vendor can supply both the rack and the PDU. The compatibility of the two goes a long way to ensuring ease of use and optimises the way both components work together.

    Furthermore, agility can be further enhanced by features present on the rack PDU itself. Features such as the ability to set the IP address, rotate the display if installed upside down for busway and the ability to read alarms are all available in PDUs with advanced pixel LCD displays with interactive menu systems.

    For rack PDUs with daisy-chain capability, the menu display also enables staff to quickly configure multiple rack PDUs from a single IP address and network port, facilitating the management of power supplies on different feeds through a single interface.

    The ability to establish a daisy chain can reduce physical infrastructure installation costs by 75% – through the reduction of network ports. This reduction saves on expenses and simplifies management, both factors that can increase agility.

    Advanced rack PDUs

    Even the most agile environment is at risk if the prospect of downtime remains a concern. Here, next-generation advanced rack PDUs can have a significant impact. One factor that affects reliability is issues associated with IEC plug retention. It is not uncommon for plugs to get jogged loose in the rack, leading to server shutdown. A rack PDU with IEC plug retention prevents the accidental dislodgment of a plug and can greatly enhance reliability. There are a few methods to secure the plug, but a solution integrated into the outlet is ideal to avoid the bulk of external clips or cable trays. It is also important to avoid solutions that require proprietary power cord solutions that involve additional expenses. On the other hand, an integrated IEC outlet grip reduces the total cost of ownership and improves reliability.

    Ease of installation is also worth bearing in mind. Not only are they more convenient and of course time-saving, rack PDUs that are easy to install save on startup and provisioning costs for customers making them an easier sell. Tool-less button mounting options for rack PDUs ensure out-of-box to install time is minimised, this solution requires a rack enclosure with keyhole (tool-less) mounting capability.

    Another way is to ensure the rack PDU has been designed for mounting flexibility. An ideal solution would have the tool-less buttons factory-installed on the PDU. This would accommodate the rack metal thickness and would have the flexibility to be mounted on the side for 90-degree mounting.

    Other mounting options may be required, so that further flexibility can be obtained, if the rack PDU has bracket mounting capabilities such as a clip foot bracket. In addition, a rack PDU with a lightweight aluminium chassis, which is 30% lighter than a steel equivalent, is also easy to install. It can even reduce shipping costs, plus it can dissipate heat better and deliver improved electrical ground conductivity.

    The process of selection should begin with the power rating of the PDU, when designing a data centre, 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. Companies want a device capable of carrying the full power load, as well as offering the possibility for capacity expansion in order to future proof. Any excess capacity that is being provisioned can be handled seamlessly simply by implementing a larger capacity PDU.

    Once the power is considered, the next step should be to evaluate the available technologies. Typically rack PDUs come in three technology categories: basic, metered and managed/switched distribution. Moving up the stack from basic to metered, will allow companies the ability to locally measure current and load balance.

    It also enables the capability to remotely monitor branch circuits and facilitate capacity planning. With advanced metering, there is an opportunity to gain the capability to meter power at the outlet level. This important functionality is required for accurate Level 3 Power Usage Effectiveness (PUE) calculations.

    Outlet-level metering also provides a level of detail in reporting power usage, which is often required in multi-tenant racks at co-located facilities. In addition, managed PDUs facilitate outlet switching which is an ideal function for lights-out operation and in situations where a fast response to remotely cycle power in the rack is needed. Furthermore, businesses can also turn off outlets when not in use thereby preventing accidental overloading of the rack PDU. Finally, outlet switching enables the ability to sequence power up and perform load shedding. These are advanced features that can be important elements of an overall power strategy.

    To conclude, it is obvious that advanced rack PDUs have the features and reliability today’s data centres need to monitor, manage and maintain power distribution in their operations. More importantly, they are capable of supporting the changing and accelerating demands of the business to facilitate seamless operation. Businesses would be wise to develop their power strategy by understanding the current rack environment, work load demands and then consider choosing the appropriate rack PDU.


    Please enter your comment!
    Please enter your name here