Intelligent (Smart) PDUs vs. Basic PDUs: A Look at the Differences and How To Choose

Choosing the right power distribution units (PDUs) has never been more important. Increasing data center densities, skyrocketing electricity costs, and the need for remote management are driving many data center operations to make strategic investments in intelligent PDU technology. At the same time, “basic” PDUs remain cost-efficient options for many applications.

Learn more about what a PDU is and how PDUs work.

What Are Intelligent/Smart PDUs?

Intelligent PDUs (also known as “smart PDUs”) collect data on various power metrics and enable the monitoring, management, and control of the power used by IT equipment. More importantly, they also connect to the network — that’s what makes the PDU a “smart” device. Data center personnel can access the PDU’s data remotely through a web interface, SNMP, SSH, or telnet session. Best-in-class intelligent PDUs also provide RESTful APIs for integration with data center infrastructure management (DCIM) applications and building management systems (BMSs).

There are two primary features associated with intelligent PDUs:

Metering

Metering allows PDUs to capture metrics such as voltage (V), current (A), active power (kW), apparent power (kVA), energy (KWh), and power factor. Some metered PDUs monitor the power input to help ensure that circuits aren’t overloaded. Others monitor usage at the outlet so IT personnel can better understand the power consumption of individual devices.

Switching

Switching enables IT staff to control individual outlets on the PDU via the network, making it quick and easy to power cycle equipment in a large or remote facility. They also enable the use of power sequencing delays to avoid accidental overloads and reduce the risk that technicians will plug equipment into any available outlet. Switched PDUs may also provide input or outlet metering.

Learn more about the different types of PDU.

When selecting a smart rack PDU, you should also consider the following:

• IP Address Aggregation. When PDUs are connected to the network, they use an IP address and a switch port. This can quickly get expensive and unmanageable in a large data center. Some intelligent PDUs allow the aggregation of multiple devices on a single IP address, reducing costs and management overhead.
• DCIM Integration. Integrating an intelligent PDU with a DCIM solution gives IT staff a single-pane-of-glass view of real-time power data. DCIM solutions also provide dashboards and reports that help data center managers optimize availability and power efficiency.
• Environmental Monitoring. Best-in-class intelligent PDUs support environmental sensors, which can monitor temperature, humidity, and other conditions without the need for a separate monitoring solution.

What Are Basic PDUs

“Basic” simply means the PDU doesn’t provide monitoring or switched outlet capabilities. While these features are increasingly important for today’s remote operations, they aren’t always necessary. A basic rack PDU can serve just as well — as long as it provides the quality your data center demands.

Basic rack PDUs come in a variety of shapes and sizes. There are several things to consider before selecting a particular model.

Input Power

Most offices in the U.S. have single-phase 120V power. Data centers and industrial sites commonly have 208V three-phase power for higher power density. It’s important to know what type of input power you have and the type of outlet you’ll need to plug the PDU into. Learn more about 3 phase PDUs vs. single phase PDUs.

Output Power

Each piece of IT equipment should specify the amount of power it needs, either on a placard attached to the device or in the user manual. The power requirements may be listed in volt-amperes (VA) or watts (W). Add up all the power, converting as necessary, to determine the output requirements of the PDU. In some cases, multiple PDUs may be necessary.

Number and Type of Outlets

The PDU should have at least as many outlets as the number of plugs for the IT equipment, ideally with some room for expansion. Note that some equipment may have two plugs. It’s also important to note the types of plugs, which correspond to the VA requirements of the equipment. Many installations will have a mixture of plugs, particularly if servers, networking equipment, and other gear are deployed in the same cabinets or rack. Learn more about PDU plug and outlet types.

Tips for Selecting the Right PDU

Here are some features to look for when selecting any PDU (check out our PDU buying guide for a more comprehensive explanation):

• Hydraulic-magnetic circuit breakers help ensure continuous operation at full current and reduce the risk of nuisance tripping due to high ambient temperatures.
• Labeled outlets and circuit breakers allow easy identification of the circuit configuration for fewer connectivity errors.
• An ultra-low-profile design improves airflow efficiency and enables easy access to IT equipment.
• Alternating small groups of outlets by circuit breaker along the width of the PDU helps to improve load balancing while streamlining equipment installation.
• High-density outlet arrangements support all the IT equipment in the rack or cabinet, minimizing the need for multiple PDUs.

High-Quality PDUs from Enconnex

Enconnex is your source for PDUs to meet every need and budget. They are available in various input and output configurations and meet the highest standards for quality and reliability. We also offer a variety of intelligent PDUs that provide multiple connectivity options and have hot-swappable intelligence modules for easy field replacement.

We are also getting ready to launch a new line of TAA-compliant, made-in-America basic PDUs. View our catalog to see all our PDUs for sale, and contact our power specialists to get more information about our offerings.