TSI

An electrical trunking system is an enclosure, usually rectangular with a removable lid, that protects and organizes electrical cables and wires. It is a larger and more accessible alternative to a conduit system, and is widely used in commercial and industrial settings where multiple cables need to be run and easily accessed. 

Types of trunking

Trunking systems are categorized primarily by material and function. 

·         PVC trunking: The most popular and affordable type, made from polyvinyl chloride. It is easy to install and lightweight, making it a common choice for domestic and office installations.

o    Mini-trunking: A very small PVC trunking ideal for surface wiring in residential and light commercial applications.

o    Skirting/dado trunking: Designed to blend into the room's decor by incorporating the trunking into the skirting board or dado rail. It can have multiple compartments for different services.

·         Metallic trunking: Formed from mild steel and coated with either enamel paint for dry indoor use or a hot-dipped galvanized coating for protection against damp conditions. It is extensively used in industrial settings due to its strength and durability. Galvanized Iron (GI) trunking is a specific, corrosion-resistant type of metallic trunking.

·         Multi-compartment trunking: Features internal dividers to segregate different types of circuits, such as power, data, and communication cables, preventing electrical interference.

·         Bus-bar trunking: Used for distributing high currents in factories and industrial facilities. It consists of insulated copper or aluminum busbars enclosed in a protective trunking shell, with tap-off points for easy connection of machinery.

·         Lighting trunking: Specifically designed for continuous runs of light fittings, especially in industrial settings. The trunking carries the supply cables and can also house control gear.

·         Floor trunking: Installed underfloor in commercial buildings and offices, with accessible junction boxes for power, data, and telephone outlets. 

Advantages of trunking systems

·         Flexibility and adaptability: It is easy to add, remove, or change circuits, which is ideal for environments that require frequent changes, such as offices and factories.

·         Cable protection: The enclosure shields cables from physical damage, dust, and moisture, extending their lifespan and ensuring safety.

·         Aesthetics: Trunking provides a neat and organized way to conceal unsightly cables, contributing to a professional appearance.

·         Safety: By containing wires, trunking reduces the risk of electrical shocks, fires, and tripping hazards.

·         Ease of maintenance: The removable lids allow for quick and easy access to cables for inspection and maintenance.

·         Cable management: Keeps cables organized and makes it easier to trace specific wires. 

Best practices for installation

·         Follow space factor rules: Adhere to regulations (such as the IEE's recommended 45% maximum fill) to ensure cables do not overheat.

·         Ensure proper segregation: Use multi-compartment trunking to separate different cable types, such as high-voltage and low-voltage circuits, to avoid interference and meet safety regulations.

·         Provide adequate support: Secure trunking directly to surfaces or suspend it using brackets, ensuring supports are placed at regular intervals, especially at joints and bends.

·         Plan the installation carefully: Lay out the trunking route beforehand, taking into account obstacles and expansion needs. Ensure a secure and level alignment.

·         Finish joints and entries properly: File all sharp edges and burrs after cutting or drilling. Use appropriate fittings and bushings for connections to prevent damage to the cables.

·         Do not overcrowd: Leave spare space for future expansion and proper heat dissipation. Overcrowding can damage cables.