All cables and conductors must be supported in such a way that the level of mechanical strain which naturally exists will not cause either the cable/conductor or the terminations to be compromised (522.8.5). Furthermore, all cable supports and enclosures shall not have sharp edges liable to damage the wiring system, and cable/conductors are not to be damaged by the means of fixing (522.8.11 & 522.8.12). It is important, therefore, that care is taken when selecting for use supports that are appropriate for the cable/conductors.
There is a wide range of options available for the contractor when selecting cable supports. These include amongst other things:
• Cable ties
• Cable cleats
• Cable clips
• Cable tie accessories
• Cable glands
The type of fixing will depend on the nature of the surface to which the support is fixed. For example, cable ties would be suitable for fixing cables installed on basket tray or cable tray, whereas cable clips would be suitable for wooden surfaces.
Similarly, the type of support will depend on the type of cable being installed. For example, cable cleats will be suitable for steel-wire armoured cables.
Guidance
The guidance issued within the On-Site Guide (OSG) published by the IET is helpful in deciding on the nature of cable support and the distances recommended between clips. Appendix D covers cables generally, specific applications such as caravans and the like, overhead wiring as well as conduit and trunking support.
For more information, check out our SGTV episode on Cable Management Systems on YouTube.