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LAN or distribution cabinets are used within networks for structured cabling and various network components such as patch panels, switches and routers. To accommodate the high volume of copper and LWL cables, the cabinets on the one hand have to have high load-carrying capacities and on the other hand they have to be equipped with assembly-friendly features to offer an orderly cable arrangement and fixing.
What are the requirements for cabinets in Network Technology?
The main requirements for a cabinet in network technology are a simple and cost effective installation, high load-carrying capacity, rational assembly and unrestricted cable access. Versatility with few assembly parts is a demand, in which cable management plays a key role.
What are the requirements for cabinets in Network Technology?
The main requirements for a cabinet in network technology are a simple and cost effective installation, high load-carrying capacity, rational assembly and unrestricted cable access. Versatility with few assembly parts is a demand, in which cable management plays a key role.
Electronics cabinet platform VARISTAR for Networking Technology
Here the assembly and accessory parts can offer all possibilities of cable ducting and fixing. Depending on the site and application the cabinets are equipped with or without doors and side panels. If front and rear doors are required, these are equipped with 180º hinges and easily removable. The front doors are mostly made from security glass, framed or unframed. Side panels and doors can be equipped with security locks to avoid unauthorised access. The integration of two 19" planes (at the front and rear) is optional for the installation of passive components. The 19" panel/slide mounts are often installed in a lowered position, so that enough space is available for the bending radius of the patch cables. Components that are not 19" are assembled on static or telescopic shelves.
These requirements are fulfilled by most of the cabinet types that are offered on the market. But particularly with cable management, cable ducting and fixing, concepts are often unclear and make simple, orderly cable ducting and in particular retrospective alterations and upgrades very difficult. Furthermore not all cabinets are suitable for the high mechanical strains through high volumes of cables. Schroff's new cabinet platform VARISTAR (picture 1), which relates to this and with its choice of cladding and an optimum range of assembly and accessory parts can be arranged as a LAN or distribution cabinet.
Prepared for high load-carrying capacity
For different requirements, the cabinet frame is manufactured in two versions. The so-called Slim-Line version provides a static load-carrying capacity to 400 kg. The specifically developed hollow chamber profile fulfils static and dynamic requirements to DL5 and DL6 of IEC 61 587-1. For applications with higher static load-carrying capacity or even earthquake stability a second version is available. The so-called Heavy-Duty version consists of an identical hollow chamber profile, but it has been lengthened in the area where the higher strain is present, thereby increasing the stability. The Heavy-Duty version guarantees a maximum static load-carrying capacity to 800 kg. Seismic tests carried out to IEC 61 587-2 describe earthquake stability to Bellcore 3; if corners are strengthened with additional brackets, even to Bellcore 4.
Tidy cable ducting
With the VARISTAR network cabinet the cabling is divided into different areas. Four defined zones (picture 2) provide tidy cable ducting and fixing of all cable possible types, so that there is a clear overview and retrospective alterations or additions to the cabling are easy to achieve.
Zone 1 is positioned in front of the installed components in the 19" plane. This area contains the patch cables, which connect the various distributors with the work stations via switches with the server room. In this zone the cables are arranged strictly horizontally, as access to the installed 19" components has to be guaranteed (picture 3).
Zone 2 is positioned to the right and left of the 19" plane, here the patch cables are guided in a rising duct to the individual planes.
Zone 3, which runs lateral over the cabinet depth, LWL or copper cables are channelled in the rear area of the top and base plates to the rear of the distribution/patch fields. Furthermore the patch cables from Zone 2 are guided via Zone 3 to the rear cable outlets.
Zone 4, at the rear of the cabinet, is arranged as an option or alternative to Zone 3, if the cabinet (against a wall with 19" swing-frame instead of the 19" profile) is not accessible from the rear. As a rule the four openings in the top are used for active cooling by the installed fans. This is required when not only passive but also active components are installed in the cabinet. The warmth created is extracted by the fans at the top in Zone 4.
These requirements are fulfilled by most of the cabinet types that are offered on the market. But particularly with cable management, cable ducting and fixing, concepts are often unclear and make simple, orderly cable ducting and in particular retrospective alterations and upgrades very difficult. Furthermore not all cabinets are suitable for the high mechanical strains through high volumes of cables. Schroff's new cabinet platform VARISTAR (picture 1), which relates to this and with its choice of cladding and an optimum range of assembly and accessory parts can be arranged as a LAN or distribution cabinet.
Prepared for high load-carrying capacity
For different requirements, the cabinet frame is manufactured in two versions. The so-called Slim-Line version provides a static load-carrying capacity to 400 kg. The specifically developed hollow chamber profile fulfils static and dynamic requirements to DL5 and DL6 of IEC 61 587-1. For applications with higher static load-carrying capacity or even earthquake stability a second version is available. The so-called Heavy-Duty version consists of an identical hollow chamber profile, but it has been lengthened in the area where the higher strain is present, thereby increasing the stability. The Heavy-Duty version guarantees a maximum static load-carrying capacity to 800 kg. Seismic tests carried out to IEC 61 587-2 describe earthquake stability to Bellcore 3; if corners are strengthened with additional brackets, even to Bellcore 4.
Tidy cable ducting
With the VARISTAR network cabinet the cabling is divided into different areas. Four defined zones (picture 2) provide tidy cable ducting and fixing of all cable possible types, so that there is a clear overview and retrospective alterations or additions to the cabling are easy to achieve.
Zone 1 is positioned in front of the installed components in the 19" plane. This area contains the patch cables, which connect the various distributors with the work stations via switches with the server room. In this zone the cables are arranged strictly horizontally, as access to the installed 19" components has to be guaranteed (picture 3).
Zone 2 is positioned to the right and left of the 19" plane, here the patch cables are guided in a rising duct to the individual planes.
Zone 3, which runs lateral over the cabinet depth, LWL or copper cables are channelled in the rear area of the top and base plates to the rear of the distribution/patch fields. Furthermore the patch cables from Zone 2 are guided via Zone 3 to the rear cable outlets.
Zone 4, at the rear of the cabinet, is arranged as an option or alternative to Zone 3, if the cabinet (against a wall with 19" swing-frame instead of the 19" profile) is not accessible from the rear. As a rule the four openings in the top are used for active cooling by the installed fans. This is required when not only passive but also active components are installed in the cabinet. The warmth created is extracted by the fans at the top in Zone 4.
Order through defined zones
Zone 1 only contains patch cables
Not "pulling strings", but laying cables
Basically there are three different kinds of cables in a distribution cabinet: copper data cables, fibre optic cables and power cables. These cables endure differing high mechanical strains, however none of them must be "pulled through", but must be arranged inside the cabinet without strains of bending, pulling, pressure and torsion. When cables are bent or creased too much this can alter the electrical or optical properties of the cables thereby reducing the transfer band widths and range. Too high tensile strain stretches the individual cables, reducing the radius or with fibre optic cables it would result in a break. Pressure strains through items resting on top or through too tight fixing with cable clamps and cable ties worsen the electrical respectively optical properties of the cables in the same way as torsion forces, which shift the cable elements to each other. Generally the instructions of the manufacturers have to be observed.
Basically there are three different kinds of cables in a distribution cabinet: copper data cables, fibre optic cables and power cables. These cables endure differing high mechanical strains, however none of them must be "pulled through", but must be arranged inside the cabinet without strains of bending, pulling, pressure and torsion. When cables are bent or creased too much this can alter the electrical or optical properties of the cables thereby reducing the transfer band widths and range. Too high tensile strain stretches the individual cables, reducing the radius or with fibre optic cables it would result in a break. Pressure strains through items resting on top or through too tight fixing with cable clamps and cable ties worsen the electrical respectively optical properties of the cables in the same way as torsion forces, which shift the cable elements to each other. Generally the instructions of the manufacturers have to be observed.
Fixing and guidance elements
In the defined Zones 1 and 2 within VARISTAR, the cabling is always arranged loosely, as the cabling is often altered through switch and patch operations. If for instance a staff member changes his work station, his PC, his telephone, his printer etc. will be switched to the new port. Strain relief is taken care of in Zone 3 and in Zone 4.
With this it will be guaranteed, that through the weight of the cables no increased tensile strains are created. The strain relief in Zone 3 in 90 % of cases is realised with C rails, which are mounted in the cabinet base; the cables are fixed with hammerhead clamps with a counter channel (picture 4).
In the defined Zones 1 and 2 within VARISTAR, the cabling is always arranged loosely, as the cabling is often altered through switch and patch operations. If for instance a staff member changes his work station, his PC, his telephone, his printer etc. will be switched to the new port. Strain relief is taken care of in Zone 3 and in Zone 4.
With this it will be guaranteed, that through the weight of the cables no increased tensile strains are created. The strain relief in Zone 3 in 90 % of cases is realised with C rails, which are mounted in the cabinet base; the cables are fixed with hammerhead clamps with a counter channel (picture 4).
Strain relief in Zone 3
Schroff has developed further simple but effective solutions for the individual zones in VARISTAR. The patch cables in Zone 1 are guided loosely with plastic clips in a horizontal direction to Zone 2. These clips, which are fixed to the 1 U high 19" switch panel with a kind of square bayonet lock (which engages with a quarter turn), have a relatively wide, rounded surface, so that the observance of the maximum bending radius is easily achievable. Additionally half and quarter circle elements are available, which are particularly suitable for the guidance of LWL patch cables.
In Zone 2 larger clips are used, which guide the cable either to the upper or lower part of the cabinet. These clips are available in three different sizes, depending on the dimensions of the cabinet. With a classic 800 mm wide and 800 mm deep network cabinet an area in Zone 2 of 100 mm (W) x 150 mm (D) can be utilised entirely. These clips can be fixed with their square bayonet lock directly to the 25 mm grid of the frame or at the side of the 19" plane. For large volumes of cables a new profile has been developed for the cable ducting. With this U profile, which has been provided with various openings and cut-outs (hammerhead perforation) and can be used over the entire cabinet height, the usually necessary reducing depth members are not required. It is fixed to the 19" plane in a position which is lowered by 150 mm and offers a multitude of cable fixing and guidance possibilities. Furthermore a grid channel system can be fixed for Zone 3, which is guiding the cables instead of the usually common C rail.
In Zone 2 larger clips are used, which guide the cable either to the upper or lower part of the cabinet. These clips are available in three different sizes, depending on the dimensions of the cabinet. With a classic 800 mm wide and 800 mm deep network cabinet an area in Zone 2 of 100 mm (W) x 150 mm (D) can be utilised entirely. These clips can be fixed with their square bayonet lock directly to the 25 mm grid of the frame or at the side of the 19" plane. For large volumes of cables a new profile has been developed for the cable ducting. With this U profile, which has been provided with various openings and cut-outs (hammerhead perforation) and can be used over the entire cabinet height, the usually necessary reducing depth members are not required. It is fixed to the 19" plane in a position which is lowered by 150 mm and offers a multitude of cable fixing and guidance possibilities. Furthermore a grid channel system can be fixed for Zone 3, which is guiding the cables instead of the usually common C rail.
