Cable tray bolt connections use bolts, nuts, and joint plates to securely join tray sections, ensuring system stability, safety, and durability.

Overview of Bolt Connections

Bolt connections are one of the most common and reliable methods for joining cable tray sections. They involve splice plates or joint plates that are bolted to the ends of two tray sections to create a straight or angled connection . This method provides strong mechanical support, maintains alignment, and allows for future disassembly or modifications.

Components Used

• Splice Plates / Joint Plates: Flat metal plates with pre-drilled holes that align with the tray ends. They are used for straight runs or angled connections and help distribute load evenly .
• Truss-Head Bolts (FRS type): These bolts pass through the tray and joint plate, securing the connection. They are often paired with combination nuts to ensure a tight, reliable hold .
• Clamps: In some systems, double clamps (e.g., DOP A2 type) are used to attach fittings to the tray rails, especially for bends or vertical sections .

Installation Guidelines

1. Align Tray Sections: Ensure the ends of the trays are flush and properly aligned.
2. Insert Joint Plate: Place the joint plate inside or outside the tray rail depending on the system design.
3. Bolt Through Tray and Plate: Pass the truss-head bolts through the tray and joint plate, securing with combination nuts on the opposite side .
4. Torque Properly: Use a spanner or torque wrench to tighten bolts to the manufacturer's recommended torque to prevent loosening under load.
5. Optional Joint Plate for Wider Trays: For tray widths of 400 mm or more, a joint plate is required to prevent transverse bending; for widths up to 300 mm, it may be optional .

Advantages

• High Strength and Stability: Supports heavy cable loads without sagging.
• Durability: Bolted connections maintain integrity over time, reducing maintenance costs.
• Flexibility: Connections can be undone for modifications or maintenance.
• Compliance: Meets electrical and building code requirements for cable management .

Safety Considerations

• Always wear protective gloves to avoid cuts from metal edges.
• Ensure bolts do not damage cables; pass screws from the inner side of the tray and secure with nuts on the outer side .
• Follow load ratings and environmental specifications for the tray system, including corrosion protection and temperature limits .

Applications

Bolt connections are suitable for straight runs, long sections, and general-purpose installations. They are also used with angled fittings, T-pieces, and crossovers to route cables around corners or junctions . This method is widely applicable in industrial, commercial, and outdoor installations where reliability and load-bearing capacity are critical. By following these guidelines, a bolted cable tray connection ensures a safe, stable, and long-lasting cable management system.