What size cable tray support should be made for a 400mm cable tray

For a 400mm (approximately 16-inch) cable tray, typical support spacing ranges from 1. 5 to 3 meters depending on tray type, load, and material.

Support Spacing Guidelines

The support spacing for a cable tray depends on several factors including tray type (ladder, perforated, solid bottom, or wire mesh), material thickness, and the weight of the cables being carried. For a 400mm wide tray: Ladder trays: Commonly supported every 1. 5 to 2.

5 meters for medium loads. Wider trays or heavier power cables may require closer spacing to prevent sagging or excessive deflection. Perforated or solid bottom trays: These trays are generally less rigid than ladder trays, so support spacing is often 1.

2 to 2 meters depending on cable weight and environmental conditions. Wire mesh trays: Due to their flexible structure, supports are typically 1 to 1. 5 meters apart to maintain stability and prevent cable drooping.

Factors Affecting Support Spacing

Cable Load: Heavier power cables require closer support spacing to avoid excessive deflection. Small-diameter control or instrumentation cables allow for wider spacing. Tray Material and Thickness: Thicker steel or aluminum trays can span longer distances without sagging, while thinner trays need more frequent supports.

Environmental Conditions: Outdoor installations or areas with vibration, wind, or seismic activity may require reduced spacing for safety. Rung Spacing (for ladder trays): Wider rung spacing reduces structural strength, so support spacing may need to be decreased to compensate.

Practical Recommendation

For a 400mm wide ladder tray carrying standard power or control cables indoors, a support spacing of 2 meters is generally safe. If the tray carries heavier cables or is installed outdoors, reduce spacing to 1. 5 meters.

Always consult the manufacturer's load charts and follow BS EN 61537, DIN EN 61537, or NEC guidelines for precise calculations. By considering these factors, you can ensure the tray remains structurally sound, prevents cable sagging, and complies with safety standards.