How to Choose the Right PDU for Data Centers—7 Questions to Ask

Posted by Enconnex Team on April 7, 2021

| Categories: Power Distribution Unit

People seldom give much thought to the power strips they use to plug in their electronics. But a power distribution unit (PDU) is much more than a power strip. Yes, it does bring power into a server rack or cabinet so that IT equipment can be plugged in. However, there are a number of factors to consider when choosing the right PDU for your data center use case.

There are two basic types of server rack PDUs. A horizontal PDU looks like a 1U or 2U piece of equipment and is designed to mount on equipment rails in a 19- or 23-inch server rack. More common today is the vertical PDU that is designed to mount in the back of a server cabinet, behind the equipment in the “0U” space. 


7 questions to ask when selecting a PDU


1. How many outlets does it have?

The number of outlets in a vertical PDU depends on its length, which is limited only by the height of the server cabinet. A basic vertical PDU will typically have 40 or more outlets in a staggered configuration. Some PDUs divide the circuit into multiple branches, each with its own fuse or circuit breaker. Alternating phase PDUs distribute power on a per-outlet basis.


2. Are the outlets color-coded?

Color-coded outlets and circuit breakers allow easy identification of circuit configuration to reduce the risk of overloading. Traditional PDUs have outlets grouped according to branches. High-density PDUs group alternating phase outlets to reduce cord clutter, simplify load balancing, and allow for more outlets in the same amount of space.


3. What is the footprint of the PDU?

Although 0U PDUs do not take up equipment space, it’s important to consider the footprint of the PDU and its impact on heat dissipation and cable management. Ultra-low-profile designs take up less space, increasing operational efficiency and airflow. This is especially important when multiple PDUs are used to support redundant power supplies.


4. What is the operating temperature of the PDU?

Because vertical PDUs are installed in the back of server cabinets, they are subjected to the hot exhaust air from the IT equipment. PDUs with a high-temperature rating reduce the risk of failure.


5. Does the PDU provide metering capabilities?

PDUs with metering capabilities reduce the risk of overloading and help data center operators plan for capacity and optimize energy use. Input-metered PDUs monitor circuit breakers and phases in real-time. Outlet-metered PDUs also monitor power loads at the outlet level. Network-connected PDUs allow technicians to view this data remotely.


6. Does the PDU have switched outlets?

Switched outlets allow technicians to power on, power off, and reboot equipment remotely and sequence the power-up of equipment. Outlet access control helps to prevent the unauthorized use of outlets.


7. Is it a universal PDU?

Universal PDUs feature a seven-pin connector that supports interchangeable input power cables. This allows global organizations to use the same PDUs across their environment, even if data center facilities have different power sources. It also enables data center operators to adapt to changing power requirements.


Enconnex Offers a Full Line of PDUs

Enconnex is your source for high-quality, reliable PDUs to meet every need and budget. Our PDUs are used in the largest hyper-scale data centers and enterprise customer locations around the world. Whether you’re looking for a basic PDU or an outlet-metered, outlet-switched unit, Enconnex offers the advanced features you need in a cost-efficient solution.

Contact one of our power experts for help choosing the right PDU for your use case.


Posted by Enconnex Team on April 7, 2021

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