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What’s all the Rack-IT about?

Mandeep Jandu, cloud, data centre & telecoms infrastructure specialist at The Rack and Cable Company UK Limited, outlines the role of the rack, as well as some key considerations when it comes to purchasing your equipment.

IT hardware, whatever form it takes must reside in some form of cabinet, rack or enclosure. In a small office or home office, it may be a simple Wi-Fi router on a desk or mounted direct on a wall. SMEs, may use simple wall-mounted racks or cabinets.

In larger organisations, corporates, governments and NGOs where IT is deployed in its tens of hundreds, we procure floor standing enclosures and cabinets.

To all racks or cabinets that host IT equipment, electrical power has to be provided and this is usually in the form of single-phase feeds.

In some instances, single phase electrical feeds are being upgraded to 3phase electrical feeds, due to IT hardware becoming ever more power hungry in today’s virtualised world.

Size matters

Racks and cabinets take up and occupy space, generally measured in square metres. In times gone-by these spaces were on premise i.e. in the same building as the people using the technology. In more recent times, they are located in purpose-built data centres or colocation centres.

Whether, on-premise, purpose-built data centres or co-located space, they all have one thing in common: cost. Therefore, designers need to consider the rack dimensions (WxHxD) suitable for the IT hardware that will serve the business and ensure space is optimised and balanced between costs and needs.

The more IT a business requires, the more racks are needed and more racks equal more space.

There are two widths associated to a rack:

1) There is the inner frame – a frame within a frame which is generically known as the 19inch mounting frame. The hardware is made to 19inches wide to fit the racks.

2) The racks external frame can measure in width anywhere from 600mm, 700mm or 800mm.

Rack depths have also changed over time, as have the depths of the hardware. Racks that measure 300mm were used for patch panels and small IT equipment.

The 600mm deep rack was mostly associated with telecoms systems, but when the data centre industry really took off in the late 90’s, the 800mm and deeper became more prevalent due to the changing hardware and the space needed at the time. 

The third dimension is the height of the racks. Rack height is generally measured in U-space. Today, 42u racks are prevalent, but all heights are visible in the data centres.

These range from 6u wall mountable through to 52u heights depending on the floor to ceiling height gap. Racks come in all heights, widths and depths and that is what the Rack-IT is about – accommodating IT hardware.

Racks and cabinets are specifically designed for IT hardware and of course everything installed will add to the weight of floor-standing racks. The rack must be robust and sturdy to mount and retain the IT hardware, and the limitation of the rack must never be breached.

Keep in mind, the rack and cabinet may support the IT weight, but the supporting floor must be able to do the same!

Once a decent, robust, fit-for purpose rack is selected for purchase, they can have a life span of over 25 years, but this is of course limited to how quickly IT outgrows the rack dimensions.

Limited access

Enclosures, cabinets and racks must also provide security, in other-words it should not be accessible to just anyone, so racks are manufactured with some form of locking mechanism on the doors.

This could be a key, a digipad, biometric scanner, ID card or a combination. Enclosures aren’t just limited to racks or cabinets, but in data centre environments also include cages within which racks are enclosed. These enclosures must themselves be secured.

In some businesses, each enclosure is secured as are the racks and cabinets. To do this, entry into the enclosure and opening of just the rack door must be governed through ITIL incident and change management.

Whilst security has a key function in making access limited to authorised persons, there is the human element to consider.

Take for example structured cabling and ease of installation/de-installation of IT hardware, maintenance and break fix works and the density of the hardware installed. The question is: Can it be worked on easily?

A good quality rack balances the structured cabling to the network and servers with the power strips and the relevant power cords.

Racks need adequate space to accommodate the IT hardware, power leads and cords, as well as the structured cabling systems whilst supporting security and ease of access to them.


In today’s cloud systems, data centre and colocation environments, the role of the rack is integral in its ability to host the vast array of IT hardware and structured cabling systems required for business.

An often underrated but unquestionably critical component, racks, cabinets and enclosures house our hardware and essentially our modern world. 

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