Patch panels vary in style and features, so how can you select the best type for an application? Andy Walls outlines the choices.

Selecting the correct panel for an application can pose a difficult task. Apart from the obvious, like using the same category of patch panels as the installation eg Category 6 panels with Category 6 cabling, in order to select the optimum patch panel for your installation many factors must be considered.

Copper choices

Copper patch panels commonly fit into one of three categories:

  • economy panels – these typically have flimsy construction, unreliable performance and a lack of technical support or warranty. Economy panels are usually labour-intensive to terminate, have poor labelling facilities and no cable management functionality. The concentration of ports per U-space is also low;
  • mid-range panels – delivering better performance than economy panels, mid-range models are usually independently tested by a third party testing house and offer some form of extended warranty. Termination is easy using industry-standard tools and the labelling is usually compatible with recognised manufacturers. Higher density panels are available;
  • high-end panels – more robust and reliable, high-end patch panels usually possess independent testing verification. They are easier to terminate with built-in cable management to support and secure the cabling. Accessories supplied include cable ties, cage nuts and a labelling facility. Some panels are equipped with integral shutters to protect from dust contamination. They can also have the ability to be integrated with intelligent patching.
  • When selecting a copper patch panel, a number of key factors need to be considered. Firstly, does the installation comprise untwisted pair (utp) or shielded twisted pair (stp) cabling? A stp cable terminated on a utp panel without the screen or drain wire terminated to a main electrical earth can cause noise or electromagnetic interference (emi) on the system. This leads to the transmitted data becoming corrupted.

    The data panel can be of modular construction allowing modules to be added or changed as required. Some modular panels allow the cables to be terminated outside the cabinet, they can then be dressed into place and clipped in the panel. This method can be an advantage on live networks as it will cause minimum disruption.

    Labelling the port with a unique identifier enables efficient operation and maintenance. When the panel is used for cross-connect, it should be colour-coded to identify the fields in accordance with ANSI/TIA/EIA-606A as follows:

    • orange – demarcation point;
    • green – network connections;
    • purple – common equipment (pbx)/lan;
    • white – first level backbone;
    • grey – second level backbone;
    • blue – horizontal cabling;
    • brown – inter-building backbone;
    • yellow – miscellaneous;
    • red – reserve for future use.
  • Cable management is designed to support cabling from undue stress, ease dressing of cables and maintain the minimum bend radius of cabling. On some panels this is an integral part of the design, others have separate cable management included or available as an optional accessory.

    Panels are available in various sizes, for example 1U panels with 16, 20, 24, 32 or 48 ports and 2U panels in 32 or 48 ports. Many budget patch panels are not available in higher density sizes.

    High-density patch panels are suitable when space in the cabinet is at a premium. These panels usually require more care when dressing and terminating the cabling as there is limited space. Labelling is also compromised by the lack of space.

    Sliding patch panels allow easy front-loading access for ease of installation, termination maintenance or addition of extra data outlets.

    The fibre alternative

    Fibre panels secure the cable, protect bare fibres and house any splices, adapters and connectors. The adapters and connectors should be protected from dust and contaminants while they are unmated.

    Fibre patch panels fit into the same three categories as copper versions:

    • economy – these often have poor spacing between connectors and are supplied unpopulated without adapters. They can be shallow, which can cause damage to the fibres;
    • mid-range – these use reasonable quality materials and have labelling that is compatible with recognised manufacturers. Panels have some cable retention and can be fixed or sliding versions with an adjustable front panel depth;
    • high-end – these are supplied with all relevant accessories including cable management spiders and/or splice supports; they are fixed on studs instead of an adhesive base, which can loosen in a hot cabinet. Cable ties, cage nuts, a fixing kit and a labelling facility are also supplied. High-end panels would normally have interchangeable front panels for the different types of connectors and are deeper to accommodate the service loops of fibres from pigtails.

    There are several key factors to consider when choosing a fibre patch panel. To start, is it used for horizontal, backbone or centralised cabling? If the patch panel is used for horizontal cabling it would normally be high density. Centralised, optical fibre cabling techniques create a combined backbone/horizontal channel within a building. The channel is provided from a work area to the centralised distributor by allowing the use of cables pulled though, interconnected or spliced. With a horizontal or centralised option, a fibre is a two or four-fibre multi-mode cable. Backbone fibre can either be multi-mode, single-mode or a hybrid fibre. Connections are usually selected to complement the network hardware.

    Consideration of the quantity and size of fibre cables entering the panel ensures that there are adequate holes of the correct size to accommodate cable glands. With small form factor connectors, 1U panels can accommodate up to 24 duplex connectors or 48 fibre cores.

    Cable retention should be available for securing the kevlar-strength membrane to the panel chassis. This prevents the fibre being pulled out of the panel and putting undue stress on the cable.

    Fibre patch panels need to provide adequate protection for the connectors against accidental contact that may disturb optical continuity or degrade optical performance. They must also allow for the removal of existing connectors and the addition of new connectors or fibres. They must be able to store and identify non-connector fibres from horizontal or backbone cables.

    Whether the connectors are to be terminated direct or using pigtails and splices, cable management should always be supplied; in the panel this enables incorporation of high-density termination. High-density termination conserves space and provides for ease of optical fibre cable and patch cord management upon installation. There should also be adequate space and provision for separate service loops of the main fibre and any pigtails used.

    Marking and colour-coding of connectors and adapters ensures that mating of different optical fibre types does not occur. This should be beige for multi-mode adapters, blue for single-mode and green for APC connectors.

    Sliding panels offer easy front access for termination and future maintenance of the fibre connectors. These panels vary from metal-on-metal sliding to special nylon runners for easy access.

    • Source

    Electrical and Mechanical Contractor

    Postscript

    Andy Walls is warranty manager for Molex Premise Networks.