Types of crossarms for cable trays

Crossarms for cable trays are structural supports, typically made of galvanized steel, designed to hold cable trays securely while meeting load and deflection standards.

Materials and Construction

Cable tray crossarms are commonly made from Q235 low-carbon steel and are often hot-dip galvanized to resist corrosion and extend service life. Their cross-sectional shapes are usually U-shaped or L-shaped, and thicknesses are categorized as 2. 5mm, 3mm, or 4mm depending on the load requirements.

For heavy-duty applications, crossarms may include stiffened structures with wider flanges (60–80mm) to handle higher loads.

Dimensions and Load Capacity

The length of the crossarm typically matches the width of the cable tray, with standard sizes of 300mm, 400mm, and 500mm. Crossarms are fixed to tray connectors using bolts, forming support nodes spaced 500–1000mm apart. Design loads vary by application: Light-duty trays (control cables): 50 N/mPower cable trays: 150–200 N/mHeavy-load scenarios (e.g., metallurgical workshops): >300 N/m, requiring reinforced crossarms Deflection and StandardsCrossarms must meet both static and dynamic load requirements.

According to G

B 50217 Code for Design of Cables in Electric Power Engineering, the maximum deflection should be ≤ L/200, meaning a 1000mm spaced crossarm should not sag more than 5mm.

Installation

Crossarms are bolted to the side connectors of cable trays, creating a stable support system. Proper spacing and alignment ensure that the trays remain level and can safely carry the intended cable load. For angled or terminal sections, crossarms may be designed to accommodate changes in direction or additional tension forces.

Advantages of Galvanized Steel

Corrosion resistance for long-term durabilityHigh mechanical strength to support heavy cable loadsCompliance with engineering standards for deflection and load In summary, crossarms for cable trays provide essential structural support, with material choice, thickness, and spacing tailored to the type of cables and load requirements. Proper design and installation ensure safety, stability, and compliance with engineering codes.