Why Hot-Swap Capability is Key to Zero Network Downtime

In the past, UPS repairs or maintenance were often a big headache for IT departments with UPS Systems that were non-modular and hardwired making them time-consuming to repair. An off-site technician was usually required to diagnose the problem, often causing an undesirable period of network downtime. But today, when high availability, resiliency and serviceability are critical requirements for network operations, UPS manufacturers have addressed the problem of downtime by engineering Hot-Swappable UPS Systems. [Read more…]

“Selling” 3-Phase Power to Management

You don’t need to know much about 3-phase power to decide whether you need it for your application. If you decide that 3-phase power is the best choice for your needs, there are some attributes of 3-phase power that can help you sell the idea to the executive suite if you get push back over doing something new and different. [Read more…]

How to Use PDUs to Improve Data Center Energy Efficiency

Energy efficiency in the data center used to be an afterthought, if it was on the radar at all. But increased processing needs and increasingly power-hungry equipment have made the power bill one of the primary costs of running a data center. The cost of powering a rack server during its operational lifespan can easily exceed the hardware cost of the server, so we don’t just consider the speed of the server anymore – we need to know how much speed we get for each watt that is consumed. Every IT organization is under pressure to manage power more efficiently.

For the purposes of improving energy efficiency, remote current monitoring is the most important PDU capability. Remote current monitoring reduces guesswork about how to improve energy efficiency. Not only can you see current usage in real-time, you can also review data and event logs to monitor trends and improve planning.

Some, but not all, “intelligent” PDUs not only support local and remote current monitoring per load bank or phase, but also per outlet. For example, our 3-Phase Switched PDUs have remote current monitoring per outlet, as well as our Single-Phase Switched PDUs. Because these PDUs give you more precise or granular data, you can get detailed information about how much power a specific device is drawing from a specific outlet.


Outlet level current monitoring is great for determining the operating cost for each individual device on the network and providing more detail about how much power each device pulls. For example, if your PDU is at 95% capacity – it’s time to bring in more electrical capacity. If one of the devices connected to the PDU pulls the majority of the power, it would be really helpful to know which one it is so you can accommodate it better without risking overloading anything. You can also determine how much work you’re getting from the device in relation to the power it consumes to decide whether it would be cost-effective to upgrade to a more energy-efficient device that delivers more work value per watt.

Knowing how much current is being drawn by each PDU allows you to optimize efficiency more easily than if you only know what’s on your monthly bill, but it’s even more helpful to know how much current is being drawn by each outlet. Knowing the current per outlet allows you to perform device-level optimization.


You can also use data logs to optimize energy efficiency, analyze trends and plan capacity in detail, using more granular data to make better decisions.

Getting it Right. 8 Things Data Center Pros Consider When Buying a PDU.

If you’re looking to buy a Power Distribution Unit (PDU) for your rack installation and need help deciding exactly what you need, here’s a few tips to consider:

1. PDUs address a broad range of power requirements. It may seem obvious, but defining your power requirements is the first step in choosing the right PDU. Are you powering a major data center with hundreds of server racks running mission-critical applications? Does the environment also include blades — or, as is happening in some cases, are the blades replacing traditional rack servers? [Read more…]

Why Monitor Power Consumption in a Server Rack?

If rack power consumption could be easily estimated and remained constant, there would be no need for on-going monitoring. However, server workload and rack configuration changes cause power consumption to fluctuate over time and have the potential to overload the circuit, causing equipment to shut down.

The problem
Power consumption in a server rack is not constant. In fact, it can more than double when servers are performing processor- or disk-intensive operations such as copying files. Power consumption can also vary by as much as 20% in servers running Windows Server, which automatically reduces the frequency of the server’s processors to save power when the machine is under low load. Variations in the performance characteristics of servers  makes it difficult for network engineers to estimate power requirements for a server rack and ensure that an overload condition does not occur.

The solution
To ensure that rack power consumption never exceeds the capacity of the circuit (protected mains, in-rack UPS or branch PDU), a network engineer could design-in a large margin of error but this would greatly increase both capital and on-going costs. A better solution is to continuously measure the power consumption of each rack in real time using a PDU capable of remote monitoring.

A Monitored PDU supports real-time local and remote monitoring of the power consumed by connected equipment.  With optional accessories, temperature, humidity, and rack security can also be monitored. If power consumption exceeds a user-configured threshold, an email or similar alert warns network engineers of potential overload conditions.