The conduit is in the cable tray

Typically, conduit is not placed inside a cable tray; cable trays are designed to support tray cables directly, while conduit is used separately for additional protection when required.

Understanding Cable Trays and Conduits

A cable tray is an open system used to support and organize multiple cables, allowing ventilation and easy access for maintenance. They are commonly made of steel, aluminum, or fiberglass and are ideal for industrial, commercial, or large-scale installations where many cables need to be routed efficiently . A conduit, by contrast, is a closed tube—rigid or flexible, metallic or non-metallic—used to protect cables from mechanical damage, moisture, chemicals, and UV exposure. Conduits are labor-intensive to install and are typically used in areas requiring high protection or code compliance, such as underground runs, outdoor installations, or hazardous environments .

Tray Cables and Conduit Requirements

Tray cables (TC or TC-ER) are specifically designed to be installed directly in cable trays without additional conduit. They are manufactured to withstand industrial environments, including exposure to mechanical stress, moderate moisture, and temperature variations . The National Electrical Code (NEC) allows tray cables to run openly in listed cable trays, provided they are properly supported and protected from excessive damage . Conduit may be required in certain situations:

• Areas with heavy equipment or vehicle traffic to prevent crushing or abrasion
• Outdoor or underground installations for UV and weather protection
• Hazardous or classified locations, such as chemical plants or explosive atmospheres
• Compliance with local building codes or insurance requirements

Installation Practices

In standard practice, conduit is not placed inside a cable tray. Instead, cable trays provide the structural support, and conduit is used separately where additional protection is necessary. This approach maintains the open design benefits of cable trays, such as easy access, ventilation, and simplified modifications or expansions . If conduit were placed inside a tray, it could reduce ventilation, complicate cable access, and negate the efficiency advantages of the tray system. Therefore, the correct method is to install tray cables directly in the tray and use conduit only where code or environmental conditions demand extra protection.