Cable Tray Systems Explained: The Right Solution for Modern Cable Management

In today’s commercial and industrial settings, reliable cable management is not a nice-to-have, it is essential. From power distribution in factories to data cabling in offices and hospitals, how cables are routed, supported and protected has a direct impact on safety, performance and long-term maintenance costs.

Cable tray systems are one of the most widely used ways to manage large volumes of cable efficiently. This guide explains what cable trays are, the main types available, how to choose the right size and duty rating, and what to consider when designing a cable tray installation.

What is a cable tray system?

A cable tray system is a structural support pathway designed to carry, route and organise electrical and data cables. Rather than enclosing cables in conduit, cable trays provide an open, ventilated support system that allows for:

• easy inspection and maintenance

• improved heat dissipation

• quicker installation and simpler future expansion

Because of this flexibility, cable trays are commonly used in commercial buildings, data centres, manufacturing plants, warehouses and infrastructure projects.

Manufacturers such as Unitrunk produce full ranges of trays and accessories that enable installers to build complete, compliant systems for a wide variety of environments.

Main types of cable tray

Different installations place different demands on cable containment. The most common cable tray designs include:

Perforated cable tray

Perforated trays have a flat base with ventilation holes along the length. They are widely used for light to medium-duty cabling and offer a good balance of strength and airflow. Typical applications include offices, schools and commercial buildings.

Ladder cable tray

Ladder trays use two side rails connected by rungs, forming a ladder-style structure. This design offers excellent strength and is well suited to heavy-duty power cables and long-span industrial runs. Ladder tray also makes it easier to drop cables out or tie them in where needed.

Wire mesh (basket) cable tray

Wire mesh trays are lightweight, flexible and easy to cut and shape on site. They are particularly popular for data, telecoms and low-voltage cabling where routes may change and quick modifications are beneficial.

Each type has a specific purpose, so choosing the right design is the first step towards an effective cable management system.

Choosing the right tray width and size

Cable trays are available in a wide range of widths to suit different cable volumes and layouts. Common widths include:

• 50mm: small runs or limited cable quantities

• 100mm: light commercial use

• 150mm: offices and smaller industrial settings

• 300mm: larger commercial and industrial installations

• 450mm: heavier cable loads

• 600mm: very high-capacity runs

Correct sizing is critical. Trays should not be filled to capacity, as overcrowding restricts airflow and makes future additions difficult. Leaving spare capacity supports better thermal performance and allows for easier expansion.

Understanding duty ratings

Cable trays are typically specified by duty rating, which indicates their load-bearing capability.

Light duty is intended for smaller cable loads such as data cabling and light power circuits, and is common in offices and retail environments.

Medium duty suits mixed power and data cabling in commercial buildings, schools and healthcare facilities.

Heavy duty is designed for large, heavy cable bundles often found in industrial plants, data centres and energy facilities.

Choosing the correct duty rating helps ensure the tray can support the cable weight safely without excessive deflection.

Materials and finishes

Material choice affects durability and corrosion resistance.

Pre-galvanised steel is cost-effective and typically suitable for indoor environments.

Hot-dip galvanised steel offers improved corrosion resistance for harsher conditions.

Aluminium is lightweight and naturally corrosion resistant.

Matching the material to the environment helps extend service life and reduce maintenance.

Accessories that complete the system

A cable tray installation is only as good as its supports and fittings. Common accessories include:

• brackets and supports

• joiners and couplers

• bends, tees and risers

• reducers

• dividers and covers

These components allow installers to create continuous, properly supported routes and accommodate changes in direction or tray size.

Installation best practice

Good design and installation are just as important as product selection. Key points include:

• follow manufacturer load tables and support spacing guidance

• ensure all fixings are secure and the tray is level

• maintain suitable clearance from other services

• bond and earth trays where required

• label routes to support maintenance and fault-finding

Routine inspection also helps identify corrosion, loose fixings, damage or overfilled trays before issues escalate.

Why cable tray remains a preferred choice

Compared with conduit or trunking, cable tray offers several advantages:

• quicker installation

• lower material costs

• improved ventilation

• simple future expansion

• excellent visibility and access

For projects with significant cabling requirements, these benefits often translate into lower whole-life costs and improved reliability.

Final thoughts

Cable tray systems provide a practical, scalable and cost-effective way to manage modern electrical and data cabling. By choosing the correct tray type, size, duty rating and material, and pairing them with the right accessories, you can create a safe, organised and future-proof cable management solution.

For contractors, facilities managers and specifiers, investing in a well-designed cable tray system is one of the most effective ways to improve installation quality and long-term performance.

FAQs – cable tray systems

What is cable tray used for?
Cable tray supports, routes and organises electrical and data cables in commercial and industrial installations. It provides an open, ventilated pathway that makes cables easier to inspect, maintain and expand.

What is the difference between ladder tray and perforated cable tray?
Ladder tray is generally used for heavier power cables and longer industrial runs, offering high strength and easy cable access. Perforated cable tray is often used for light to medium-duty cabling where continuous support and ventilation are important.

How do I choose the correct cable tray size?
Tray width should be based on the number and diameter of cables, while allowing spare capacity for future additions. Cables should not fully fill the tray, as overcrowding reduces airflow and makes maintenance more difficult.

What duty rating do I need for cable tray?
Light duty suits data and small power cables, medium duty suits mixed commercial installations, and heavy duty is used for large or heavy industrial runs. Always refer to manufacturer load tables when specifying.

What materials are cable trays made from?
Common materials include pre-galvanised steel, hot-dip galvanised steel and aluminium. The right choice depends on the environment and the level of corrosion resistance required.

Can cable tray be used outdoors?
Yes. Hot-dip galvanised steel and aluminium are commonly used outdoors or in more corrosive environments due to their improved resistance to rust.

Do cable trays need to be earthed?
In many installations, metal cable trays must be bonded and earthed in line with wiring regulations. Always follow the relevant regulations and manufacturer guidance.

How often should cable tray systems be inspected?
Regular inspections are recommended to check for corrosion, loose fixings, physical damage or overfilled trays, particularly in industrial settings.

For more information on Cable Tray Systems Explained: The Right Solution for Modern Cable Management talk to Expert Electrical Supplies Ltd