How To Choose Your Rack Cabinet

I bet you Got here because you have to choose rack cabinet of some sort, but don’t know EXACTLY what to choose. Maybe you don’t know if it should be stand-alone, or wall mounted? Anxious about those complicated depths and heights? Or maybe just don’t know which door type is best suited for you? Don’t worry, I got you covered! Rack cabinet may seem as simple product, but there are some points that make you wonder, right? Below handbooks will guide you through important parameters, and will explain why those racks are sometimes called server or telecommunication cabinets.

Let’s start from beginning – what is rack? The mythical “rack” is a system for mounting devices inside cabinets and open frames. It is standardized, and thanks to that, knowing the given device has rack-sized chassis, you can be certain it will fit into your cabinet for example.

Main Dimension Parameters Of Rack Cabinets

Installation Width Inches

This parameter is most commonly 19”. Some devices, mainly targeted for small installations may use 10” width, and some huge severs may be built in 21”width, but these are very rare.

Height In U Units – Nominal Height

For standardization purposes, installation height in rack cabinets is given in U units, that can be used in every cabinet. 1U is 1,75 inch, which is 44,45mm. Most accessories installed have1U to 4U height, and knowing the total U units that your network devices will need, will give you the height needed. It is necessary however to remember thatU units give you inside installation height, not outside cabinet or frame dimension.

External height, or so called total height –it is closely tied to cabinet construction and may be different for same nominal height, thanks to various equipment, such as cooling fans in roof or castors.

As for other external measurements– depth and width, there is no official standards – however, due to functionalities, there are some certain sizes are being made by almost all producers.


Typical are 600mm and 800mm, where600mm is basic type, and 800mm is extended one. In 800mm cabinets it is easier to maintain large wire bundles, s additional width can be used to install cable management systems inside the cabinet.


There is some variety here. For wall-mounted cabinets there are 450mm,550mm (dual-section) and 600mm. Standing rack cabinet on the other hand,  can have depth 600mm, 800mm, 1000mm, and even 1200mm. Important thing here – external depth does not tell directly, how deep device can be installed. Different cabinets vary in construction, an doffers different amount of space inside them. Many of them is modular, which means rack rails inside can be placed in different position –but also there has to be some space left on back and front of each device to allow proper cable management, and air flow. 

Installation Depth

This information is different for every cabinet, and usually you can read about that in cabinet’s description. As you can see, the construction of this particular cabinet is designed so you get 100mm in front and back of the cabinet to manage cables and such.


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