Which type of system is chosen for the safe and effective distribution of electrical and data services around any particular premises will depend on the function of the building, and to some extent on the number of individual connections required, as this
For commercial, public and institutional buildings, putting the services under the floor is most appropriate, being out of sight and yet readily accessible. Power cables can either be laid in trunking embedded in the floor screed, or the power distributed via powertrack installed in the void under raised floors.
To these two long-standing and established methods has been added a third underfloor system, thought to be unique. Spider, as it is called, is specifically designed to facilitate speedy re-connection of power and data cables to computer workstations when these are re-located. In offices where desks are frequently re-located this system helps to reduce the so-called 'churning' costs.
Wire frame cable tray is an excellent choice:
Where having cables out of sight is not desirable; where in fact it may be advantageous to have them in sight, such as in hospitals, factories, warehouse and plant rooms, then wire frame cable tray is an excellent choice. Versions are now available that can take heavy industrial cable as well as communication and data cabling, and both can be in the same tray. Furthermore, this tray can also be used for carrying cables within a floor void if required.
Underfloor cable management:
Screeded power trunking is particularly suited for premises where the locations of dividing walls have not been decided or are liable to change. Hence its common use in speculative buildings. With the use of junction boxes, concealed outlet boxes and vertical access boxes, it is possible to provide an optimum layout of accessible trunking in floors with a minimum screed of 55mm.
Where screeded trunking is installed in floors with hard surfaces, such as stone, marble, wood or ceramic tiles, it is now possible to obtain floor boxes and grommets that will match these surfaces. Some versions of these products are additionally suitable for wet wash environments. These products have been designed for installation in premises with large public floor areas such as shopping malls, air terminals, banking halls, and even car showrooms. They make it safer and more convenient for cleaning staff to plug in their equipment without the need for otherwise overlong trailing leads.
Powertrack underfloor busbar system:
Powertrack, in essence an underfloor busbar, is designed to provide maximum flexibility in power distribution in raised floor applications. It comes in various lengths, which can be connected via flexible interlinks to achieve maximum floor coverage. It is available in different ratings up to 63A and access to floor boxes and grommets is provided by tap-offs. Grommets are designed for either power or data cabling.
For shallow or already overcrowded underfloor voids, it is possible to obtain floor boxes that are no more than 80mm deep. The same manufacturer also offers the availability of a support system for its powertrack installed in deeper than usual voids.
Also designed for raised floor applications is the Spider distribution system. It comprises an underfloor galvanised steel box to which are connected 50mm diameter flexible tubes, carrying power and data cabling under the floor to service points for workstations. The hub contains power and data units that feed up to eight desks.
Easy relocation:
Up to 12 tubes can be connected to the hub, but at any one time only eight of the them will be carrying cabling, leaving five empty. The availability of these empty tubes enables desk re-location to be achieved without the need for re-patching of data networks, or reconfiguring of telephone extensions, as would be necessary in a conventional underfloor cabling system. When a desk linked to the Spider is to be re-located the services to the desk are disconnected at the hub and the cable pulled back to the desk. After the desk has been moved to its new location a cable feeder is used to pull the cables back from the new location to the hub where the services are re-connected to their original socket outlets. It is an easy and quick underfloor cable system to install.
By providing maximum saturation of power and cable services without the cost of flood wiring, Spider enables a workstation to be moved without the need to re-patch data networks or re-configure telephone extensions.
Overhead cable management:
Where concealment of electrical and data services is not an issue - indeed where it might be considered to be disadvantageous - the use of open wired cable tray can be recommended. Up until now, the perception has been that open wired cable tray is only suitable for carrying data cabling. That perception has been shattered with the availability of open wire cable tray that is not only capable of supporting heavy-duty high voltage armoured power cables, but is also more adaptable versatile and faster to install than conventional cable tray. It is constructed of steel wires of up to 6mm in diameter formed into 50 x 100mm grids. It has a higher strength to weight ratio than conventional steel tray, offering the strength of an equivalent steel tray for half the weight. This enables it to support a large number of data and power cables whilst being easy to transport and install.
The open wire construction of this cable tray exposes cable to good natural ventilation, thus reducing the need for cable de-rating due to the build up of heat often associated with conventional sheet steel cable trays. Another benefit is that changes in level and direction are easily accommodated by forming the tray into the shape required, without the need for special fittings or tools. Cable trays can be cut and bent to change level, form radius bends, sweeps and tees on site.
In addition, unlike conventional perforated sheet steel tray, open mesh does not collect dust and debris, making it suitable for applications where cleanliness and hygiene are important. The open design also makes cable identification easier.
The choice is yours:
Whilst this new open wire cable tray is primarily intended for overhead installation or wall mounting, it can also be used in underfloor applications. This probably makes it about the most versatile power and data cable management system available, and is certainly a welcome addition to the marketplace. But, as has been already demonstrated in this article, other systems, or indeed the combination or several systems, will always provide the particular solution for each particular application - the choice is yours.
Contact: John Forsyth
Novar Intelligent Building Systems
The Arnold Centre, Paycocke Road,
Basildon, Essex SS14 3EA
Tel: +44 (0) 1268 563000
Fax: +44 (0) 1268 563483
Email: [email protected]
Web: www.novar.com