Here Nick Hayler, Technical and Product QA Manager at Marshall-Tufflex, provides a guide to cable management systems and the factors to consider when selecting the appropriate solution for a project.
Cable management is an essential part of the design of any building as it has an impact on the function of the building’s systems as well as the safety and experience of occupants. Therefore, there are a number of key considerations when choosing the correct trunking solution.
INSTALLING IN A MATERIAL WORLD
The selection of the right material is important and there are several options including PVC-U, aluminium and steel. The choice of material will depend on the type of building and the specific requirements of the application. For example, certain environments may require a more robust system so an aluminium or steel system may be preferable. While typically higher in cost, both provide an option that has high mechanical strength and impact-resistance, ideal for high-traffic environments such as hospitals and schools. Furthermore, steel and aluminium provide high-quality protection against electromagnetic interference (EMI) on data cables.
However, if a more cost-effective solution is required it may be better to look at a PVC-U product. PVC-U systems are lightweight and easy to install with adaptations easy to make on-site. Products from leading suppliers are now manufactured from recycled content, in some cases an average of 80% and even as much as 100% recycled content for some white trunking extrusions. Although PVC-U does not naturally provide protection against EMI it is possible to have a special copper conductive coating applied to the relevant section of the
trunking or fittings to provide screening for the data cables. Steel or aluminium dividers can also be used to separate power and data cables to reduce EMI.
HEALTHCARE
Furthermore, there may be environments where a solution with enhanced hygiene properties is required, such as those with an anti-microbial treatment. These products feature silver ions manufactured into the PVC-U that disrupts the key cell functions of bacteria and prevents them from reproducing, effectively killing the bacteria due to its short lifespan. This ongoing anti-microbial protection prevents 99.9% of harmful bacteria from surviving on its surface. These products are commonly specified for hospital and clinical environments where infection control is absolutely vital.
SIZE DOES MATTER
The number and types of cable that need to be contained should also be considered. When choosing the cable management product you must ensure that there is sufficient space within the system as if too many cables are housed in a small space it can cause overheating. The guideline rule is that no more than 45% of the space within the conduit or trunking can be occupied by cables. To establish this, electrical contractors must calculate the cross-sectional area of each cable (including the insulation) and compare the total to the size of the trunking. It is also best practice to separate the different types of cable as detailed in BS EN 50174. To achieve this, contractors should look for systems with separate compartments, many are available with three sections as standard that can then be subdivided if necessary. Individual covers on each of the main sections will help ensure ease of access.
UK WIRING REGULATIONS – THE HOT TOPIC
Electrical contractors also need to be aware of all the relevant regulations with regard to the management of cables and understand that the requirements may vary depending on the location or type of installation. With the update of the 18th Edition IET Wiring Regulations, all cables must be supported against a premature collapse in the event of a fire as trailing cables present a hazard during evacuation and to fire crews entering the building. Cables should be secured in fire-resistant trunking systems and secured using fire-resistant cable clips. Leading suppliers, such as Marshall-Tufflex provide clips and trunking systems designed to be fire-resistant on temperatures above 1000°C for up to 120 minutes.
DESIGN CHOICES
There are also a range of specially designed cable management systems to fulfil particular needs. Bench trunking is a robust angled trunking that can be mounted directly on to desks, work benches or fitted under shelving. It can either be fitted at the edge (single sided) or in the centre of desks (double sided). Compact systems are available where space is physically limited such as below window sills. While these do not have the capacity of the full size systems, they can help overcome certain installation challenges. There are also cornice trunking products available that provide an elegant and unobtrusive concealment for surface wiring around ceilings.
Choosing the right trunking system for the project is crucial to improve the experience of occupants, ensure the performance of the building systems and to provide a safe environment.
To find out more about Marshall-Tufflex’s range of trunking solutions visit www.marshall-tufflex.com.
