Trough cable trays are partially enclosed trays that provide continuous cable support, but not all outdoor cable trays are necessarily trough-type.

Trough Cable Tray Characteristics

A trough cable tray features a continuous or partially ventilated bottom with solid side rails, without the transverse rungs found in ladder trays. This design emphasizes continuous cable support while maintaining moderate structural strength, making it suitable for protecting cables from sag and mechanical stress . Trough trays can be partially ventilated to allow airflow, which helps dissipate heat while still offering more protection than open ladder trays .

Outdoor Applications

While trough trays are often selected for industrial indoor installations and power distribution systems, they can also be used outdoors if the material and protective coatings are suitable for environmental exposure, such as corrosion-resistant metals or fiberglass-reinforced plastics . Outdoor cable trays may also include ladder, perforated, or solid-bottom types depending on the project requirements, cable type, and environmental conditions .

Key Considerations

• Cable Protection: Trough trays provide better protection against mechanical damage and reduce cable sag compared to ladder trays .
• Ventilation: Partially ventilated trough trays allow moderate airflow, balancing heat dissipation and cable protection .
• Material Selection: For outdoor use, trays must resist UV, moisture, and corrosion. Trough trays made from galvanized steel, aluminum, or FRP are commonly used .
• Cable Type: Single conductor and Type MV cables may require ladder or ventilated trough trays according to NEC standards, while solid-bottom trays are generally restricted in certain hazardous locations .

Conclusion

Trough cable trays are a versatile option that can be used outdoors, but they are not the only type suitable for outdoor installations. The choice depends on cable type, environmental exposure, and structural requirements, and engineers often select the tray type that best balances protection, ventilation, and load support .