What Is a Cable Tray?
What is a cable tray?
Cable trays and cable ladders are generally used to support and route large volumes of cables.
Since there are different types of cables—such as power cables, high-voltage cables, heat-resistant cables, telecommunication cables, and others—their installation methods and supporting systems also vary. For example, cable ladders are commonly used for heavier or high-voltage cables that require better air circulation and temperature control, or when cables need to be routed vertically along walls.
Cable trays, on the other hand, are mainly used for lighter cables, electrical conduits, and horizontal cable routing across ceilings. Many cable trays are perforated to allow minimum required airflow, helping with heat dissipation.
There are also low-current and lightweight cables that do not require traditional cable trays. These cables can be routed using wire mesh trays, which are commonly used for telecommunication systems and data centers.
Structure, Materials, and Standards
All the mentioned cable support systems can be manufactured from various materials such as steel (CS.ST37 – CS.ST12) with different coatings:
Hot-dip galvanized: for humid environments.
Electrostatic powder coating: for exposed/visible installations.
Pre-galvanized sheet: for dry, low-humidity areas.
Stainless steel: for highly corrosive and humid conditions.
The structure of these systems requires careful consideration of multiple design factors, primarily based on the type and volume of cables to be supported, in accordance with the Cable Loading Standard. In short, this standard specifies, this type and volume of cable can be supported using a cable tray of width W and height H, installed in sections of 2–3 meters.
Beyond width and height, the material, thickness, and length of sections, as well as the number of bends used, directly impact both the strength of the system and its pricing. 2-bend trays minimum strength, mostly for covers, 4-bend trays with medium strength and 6-bend trays (Heavy Duty) for maximum strength.
What is the cable tray? Although a cable tray is not a complex piece of equipment, precision in design and execution—in compliance with standards such as LOADING, BENDING, ASTM A123, IEC 61537—is essential to transform it into a durable and reliable system capable of carrying large cable volumes in your project. Since cables rarely run in a straight path, they often require branching through Elbows (bends), Tees, Cross junctions, Dividers, Reducers and Inside/outside bends. The bending radius of these components is critical to prevent cable damage. For example, the allowable bending in a “Tee section” must comply with BENDING standards and the specifications of the purchased cables.
Two common questions regarding galvanized trays are, should Hot-Dip Galvanization (HDG) be used or is fabric Galvanized sheet sufficient?
As previously mentioned, the application areas of these two types of cable tray materials differ.
In fact, in the case of hot-dip galvanized trays, the cutting, punching, and bending processes are performed on raw steel sheets (either cold-rolled/oiled or black steel sheets). Afterward, according to ASTM A123 standards, the required zinc coating thickness is determined based on the sheet thickness, and the entire component is immersed in a bath of molten zinc to ensure a complete and uniform coating.
This process provides an additional advantage: in the event of surface scratches, the formation of a galvanic cell enables the zinc layer to bond with the exposed steel surface, thereby allowing partial self-repair (cathodic protection) at the damaged area.
However, in the case of pre-galvanized (mill-galvanized) trays, the zinc layer is applied during the steel manufacturing process itself, resulting in a much thinner coating. Subsequently, the cutting, punching, and bending operations are carried out, which expose the inner steel surface at the processed edges. Consequently, these sections become highly susceptible to corrosion, even at the cut or punched areas—let alone in the case of deep surface scratches. Therefore, the use of such material is not recommended in humid or corrosive environments.
Up to this point, we have provided a brief overview of this equipment.
The complementary components and fittings required for the installation and routing of cable trays and ladders will be described in detail and with illustrations in the following sections. Please stay with us.
Moreover, please note that you do not need specialized technical knowledge to equip and secure your projects, as the professional experts at Ader Tavan Nami Company, with over 2,000 executed projects in the past 8 years, will accompany you through all production stages — including consultation, design, manufacturing, installation, training, and commissioning — thus eliminating the need for specialized technical expertise on your side.
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