Trough-type cable trays use a variety of elbows—horizontal, vertical, and combination bends—to route cables efficiently while maintaining proper support and bend radius.

Types of Elbows

1. Horizontal Elbows
   • Change the direction of the cable tray on the same plane.
   • Common angles include 30°, 45°, and 90°.
   • Used to navigate around walls, columns, or other obstacles without altering elevation .
2. Vertical Elbows (Risers)
   • Allow the tray to move upward or downward between different elevations.
   • Can be inside or outside vertical bends depending on whether the tray turns inward or outward relative to the bend .
3. Combination or Multi-Angle Elbows
   • Used when a change in both horizontal and vertical planes is required simultaneously.
   • Often custom-fabricated to meet specific routing needs in complex installations .

Material and Construction Considerations

• Trough-type trays and elbows are typically made from steel (galvanized or stainless), aluminum, or fiberglass-reinforced plastic, depending on environmental conditions and load requirements .
• All elbows should maintain the minimum bend radius for cables to prevent damage and ensure compliance with standards like NEC Article 392 .
• Fittings are designed to match the width and depth of the straight tray sections to ensure smooth cable transitions .

Installation Notes

• Elbows are connected to straight sections using splice plates, bolts, and nuts to maintain structural integrity .
• Covers may be added to protect cables from dust, debris, or mechanical damage, especially in solid-bottom trough trays .
• Proper support, such as wall brackets or trapeze hangers, should be installed near elbows to prevent sagging and maintain alignment .

Summary

Trough-type cable trays rely on horizontal, vertical, and combination elbows to navigate changes in direction while supporting cables safely. Selection of elbow type, material, and angle depends on the installation environment, cable type, and compliance with electrical standards. Proper installation ensures cable protection, accessibility, and long-term system reliability .