4U 19-inch wall-mounted data cabinets
4U 19-inch Data Cabinets
A 4U 19-inch data cabinet is a compact choice when your networking equipment needs only a small amount of rack space. Explore available wall-mounted cabinets, check the total U height of your devices and make sure there is sufficient depth for connectors and cabling.
Compare 4U data cabinets
Compare available depths and assembly options for compact 4U network installations.
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4U 300mm Deep 19"
Is a 4U data cabinet big enough?
A 4U cabinet is a tidy solution for a small network, provided everything fits. Before you choose one, check the rack space used by each component and the depth of the equipment you plan to install.
Count the rack units
Four rack units fill quickly. Add up the space occupied by rack-mounted switches, patch panels and accessories. A shelf mounts in its own U, but the equipment on its platform can also extend into the space above. Measure the complete arrangement rather than automatically adding a full extra U for every device on a shelf.
Check depth as well as height
A 4U cabinet might have enough vertical space but still be too shallow for your switch or other equipment. Measure from the front mounting ears to the rear of the device, then allow space for power leads, connectors and cable bends.
Would 6U give you more breathing room?
If you are already using nearly all four units, a 6U cabinet may be worth the extra wall space. The additional room can make patching and maintenance easier and give you somewhere to put a future device.
Need help planning your installation? Try the Cabinet Finder or use the Cabinet Builder to select compatible accessories.
4U Data Cabinets: Your Questions Answered
Make the most of four rack units with advice on equipment fit, shelves, cable clearance and leaving room for additions.
How do I work out how many U of cabinet space I need?
Add together the rack space required by everything you intend to mount: patch panels, switches, shelves, horizontal PDUs, cable managers and any other rack-mounted equipment.
Then consider equipment sitting on shelves. The shelf may occupy 1U at its mounting position, but the equipment resting on its platform may extend through that U and require additional clear space above it.
Finally, leave some room for growth if possible. A cabinet calculation that arrives at exactly 12U for a 12U cabinet is mathematically impeccable and operationally rather optimistic.
Does a shelf itself use rack space?
Yes. A rack shelf occupies the rack positions used by its front mounting flange. Our current front-mount shelves are 1U models, although future shelf variants may use more rack space.
There is an important distinction between the rack space occupied by the shelf mounting and the vertical clearance available above its platform. The platform is situated towards the bottom of the shelf's occupied U, so equipment placed on it extends upwards through that same rack space before requiring additional U positions above.
A device approximately 1U high on a 1U shelf therefore does not automatically require 2U in total. Measure upwards from the shelf platform and allow the actual equipment height plus any required ventilation or access clearance.
How should I allow for non-rack equipment that will sit on a shelf?
Start at the shelf platform, not at the top of the shelf's nominal rack position.
Because the platform sits towards the bottom of the U occupied by the shelf, roughly the first U of equipment height can occupy that same vertical region. If the device is taller, you then need enough clear rack space above it for the remainder, together with any ventilation or access clearance it needs.
Also check depth, rear connectors and cable bends. A modem that’s 40mm high may be delightfully well behaved; a 130mm-high NAS sitting on the same shelf has rather more ambitious plans for the U positions above it.
Round upwards where necessary and allow useful clearance rather than designing a three-dimensional game of Tetris around the device.
Should I leave spare U for future expansion, and how much?
Yes, where space and budget allow.
There’s no universal percentage because some installations are effectively finished on day one while others acquire new equipment regularly. Even one or two spare U can be valuable in a small installation; more is sensible if you already expect the network to grow.
Buying a cabinet in which the final available U is occupied during the initial installation is wonderfully efficient — right until somebody buys one more switch.
In extremis, you can then find yourself replacing an entire wall-mounted cabinet because a device 44.45mm high has appeared.
A little unused rack space is usually much cheaper than replacing the enclosure later.
How should I measure the depth of rack-mounted equipment?
Measure from the front mounting face, where the rack ears sit against the cabinet profiles, to the rearmost part of the chassis.
Then look at what sticks out beyond it.
Power plugs, network connectors, fibre connectors and cable bends all need space too.