Power distribution units (PDUs) are an essential part of the IT infrastructure. Without them, there would be no real way to plug in IT equipment! As the name implies, PDUs bring electricity from a utility power source, generator, or uninterruptible power supply (UPS) to the racks and cabinets distributed throughout the data center. They use electrical current from one source to power multiple devices.
Beyond that basic definition, PDUs vary widely in terms of features and functionality. We’ll list a few common configurations below:
PDUs also have different types of plugs, receptacles, and power cords to meet various requirements. A basic understanding of these components is essential to selecting the right PDU for your environment.
One of the first things to determine when choosing a PDU is what PDU connector or plug types your configuration calls for. Input connectors, or plugs, attach the PDU to the input power source. In essence, the PDU plug needs to match the receptacle. The International Electrotechnical Commission (IEC) and National Electrical Manufacturers Association (NEMA) have established standards for plug and receptacle types, which are designated by codes.
The choice of PDU plug — and the PDU itself — also depends upon whether the power is single-phase or three-phase. Most office buildings use single-phase power, while larger data centers and industrial facilities use three-phase power.
Choosing the right PDU outlet or receptacle types is also an important consideration when choosing a PDU. It’s often necessary to power both 120V IT devices as well as more demanding servers. As a result, many PDUs have multiple NEMA 5-15R and 5-20R receptacles. Some have combinations of NEMA L5-30R and L6-30R and IEC 60320 receptacles. Before ordering a PDU, you should determine the type and number of plugs of the equipment in the rack and configure the PDU accordingly. It’s good to have extra receptacles for expansion, as long as the PDU isn’t overloaded.
The last piece of the PDU puzzle is PDU power cord size. Input PDU power cords (also known as PDU whips) typically range from 10 to 15 feet and have a heavy-duty construction for safety and durability. Output PDU power cords (also known as jumper cords) lengths can vary from 1 to 15 feet. The most important thing to consider when choosing both input and output PDU power cords (outside of plug types) is the amperage and voltage they support. Input cables need to sufficiently handle the power generated from the main power source and the output cables need to support the power draw coming from each individual device to maintain efficient performance and safety.
The diameter of the power cord determines the amperage it supports. In the United States, diameter is commonly measured in terms of American Wire Gauge (AWG). Internationally, diameter is measured in square millimeters (mm2). With AWG, the lower the number, the thicker the cord is and the higher the amperage it supports. For example, three-phase power cords are thicker and heavier than single-phase cords. Input PDU power cords (PDU whips) typically range from 10-4 AWG and output PDU power cords (jumper cords) typically range from 18-14 AWG.
Enconnex has a wide selection of PDUs in our Reno, NV warehouse. If we don’t have what you need, we can get it pretty quickly.
When you buy Enconnex PDUs, you get superb value, great quality, and quick delivery from a company you know and trust. Our team has extensive PDU expertise to advise you and help solve your specific challenges. Get in touch with a PDU expert today.