Bringing data and power services to the workstation
Power and data cabling systems for installing under raised floors include busbar.
Bringing data to office desks is every bit as important as bringing power — and is becoming more so. ALAN DURRANT explains the approaches available and how are they evolving? There is currently a strong growth requirement for data everywhere — in the retail, school, commercial and industry sectors. Data, fibre optics, telecom and power are all being integrated into labour- and cost-saving containment systems which often need upgrading to meet ever-evolving standards and practical requirements. There is also much greater emphasis on the products being attractive, as well as being as easy to install as possible. Recently, there has been a fundamental change in office-design thinking. The problem is no longer simply just how to get power to the desk, but how to get data to the workstation. It has been estimated today that there are 2.3 power sockets/person in the typical modern office. These accommodate PC, monitor and, usually, a shared printer. Additionally, as the cable systems evolved, installers had to be trained to successfully install the data systems. Nowadays, however, some power- and data-management systems have ceased being specialist fields, so many electrical contractors can correctly install Cat5e structured cabling systems with the minimum of professional training. A range of solutions has been developed.
Dado and skirting trunking. The latter is already less popular than dado, and this decline may be accelerated with the introduction of Part M of the Building Regulations. Dado trunking with two or three compartments is a common way of taking data and power to the office desk. It is segregated so that, usually, power and data cables are contained in the top or bottom compartment, leaving the central compartment free for easy installation of the accessories. This is an attractive solution that can meet the structured cabling requirements for Cat 5e and Cat 6. Crucial, however, is careful management of data around corners, whether external or internal. The bend radius is critical in avoiding data corruption or loss. For the same reason, the bend radii at the data-cable terminations to the data modules (located where required along the trunking) are also critical. Typically, the bend radius must not be less than four times the cable diameter once the cables have been installed.
To ring power and data services to workstations, dado trunking is and Deskpods are popular methods.
New dado trunking. The latest trunking, like MK’s Prestige Compact, has a number of features that make installation as easy as possible. Its 2-part hinged corners ensure that the data cable is installed to the prescribed minimum radius, while giving a smooth, professional appearance — even when the wall angles are not fully true. In addition, a special backless, bottomless and topless back box makes accessory installation very simple, as there are no holes to make. Further, knockouts along the length of the trunking allow easy access to cables as they pass from the upper or lower compartment to termination. This trunking can cater for almost any configuration of data and power.
Screeded floor systems. Of the hidden systems, screeded floor arrangements are popular, especially where there is low floor-to-ceiling height or heavy traffic. The various cables are laid in trunking set into the floor to serve pre-wired floorboxes. However, today this approach is considered to lack flexibility, especially when office layouts are constantly changing. In addition, modern office design tends to favour raised floors. Raised floor systems. These are a flexible and very popular option, with cable running in track with tap-offs located at strategic positions. There are two ways of bringing power and data to the workstation. The first is via floor boxes directly. The second is to use a desk module (Deskpod). Here, cable exits the raised floor through a special grommet — such as those made by Ackermann — and joins the desk via the module fitted somewhere on the desk. Fused or unfused desk modules can be provided with clean earth, power/data points, and even satellite communications.
The ‘Spider’. Unique to Ackermann, the Spider comprises a galvanised housing, power unit (with MCB and RCD protection) and data hub in one unit. Each hub can feed up to eight desks, through outlets fed by flexible tubes called ‘umbilicals’ leading to grommets. Power and data is fed to the underfloor ‘hub’ (rather like a sub-floor patch panel). The aesthetically pleasing Spider system is ideal for high-churn City and money-market applications.
The ‘Onix’. This is another modern Ackermann floorbox system. Onix is a very-heavy-duty solution and one that is highly attractive in prestige modern interiors, as it can be faced with various luxury finishes (including marble or wood) to suit interior floors. It is for example, ideal for use in marbled reception areas, and also in shopping malls, as it can also be washed. In terms of installation, there are many aspects to consider. An essential one is how many data points to provide. Installers should allow 20% over-capacity for a degree of future-proofing. The increasing demand for broader bandwidth will require the ratification of augmented Cat 6 with the implication that cable diameters may increase, as will minimum bend radii. Power over Ethernet (PoE) is already being used in many applications. Many more are examining its potential for cost savings and efficient network design. PoE provides power (usually DC) over twisted-pair cable, normally used purely for voice, data and video. DC enables top-quality power for devices such as IP telephones, but the number of new applications is increasing rapidly. Another continuing development to watch for is wireless technology. It has been around for decades, but today, with ever-increasing bandwidth, such technology may well have implications for much of the data cabling in the modern office.
Alan Durrant is product manager with MK and Ackermann UK, The Arnold Centre, Paycocke Road, Basildon Essex SS14 3EA Choosing data-cable categories • Cat5E is cost effective, simple to install and supports applications including Gigabit Ethernet. If 10/100/1000 Ethernet is required, the 100 MHz bandwidth will be acceptable. • Category 6 costs a little more. It is more difficult to install, but has greater bandwidth (200 MHz — tested to 250 MHz). However, this is not normally enough to support 10-Gigabit Ethernet (10GBase-T) beyond about 50 m. • Augmented Category 6 is the new UTP cabling platform currently being developed. • Category 7 is an expensive and complicated fully shielded system which boasts a 600 MHz bandwidth. Only a small amount has been installed so far. A balance between budget, performance and technology is crucial in determining the best choice for any specific application.
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