There is a conduit in the center of the cable tray

Placing a conduit in the center of a cable tray is permissible if it does not exceed tray fill limits and proper separation and support requirements are maintained.Cable Tray Fill ConsiderationsCable trays have maximum fill limits defined by NEC Article 392, which vary depending on tray type and cable size. For ladder trays, the sum of the cross-sectional areas of all cables and conduits must not exceed the tray's usable area, while solid-bottom trays have reduced fill capacity, typically 20–40% less than ladder trays . Conduits occupying the center of the tray count toward this fill, so it is essential to calculate the total cross-sectional area to avoid overfilling, which can lead to overheating or maintenance difficulties .Separation and SafetyNEC requires separation of power, control, and communication cables to prevent electrical interference and cross-talk. If the conduit carries power cables, it should be positioned to maintain adequate separation from sensitive control or communication cables, or a divider should be used within the tray . Conduits carrying cables rated above 600 volts may require additional separation or barriers from lower-voltage cables .Support and InstallationConduits in cable trays must be properly supported to prevent stress on the cables and maintain structural integrity. Supports should be provided at intervals according to the tray manufacturer's recommendations, and cables within the conduit should be secured to prevent movement . Ladder trays provide the best ventilation, so placing a conduit in the center is acceptable as long as airflow around other cables is not obstructed .Practical RecommendationsVerify the tray's maximum fill area and ensure the conduit plus any other cables do not exceed it .Maintain separation between power and communication/control cables, using dividers if necessary .Secure the conduit and cables to prevent sagging or stress on connections .Consider tray type: ladder trays allow better ventilation, while solid-bottom trays may require reduced fill . By following these guidelines, a conduit can be safely installed in the center of a cable tray while remaining compliant with NEC standards and ensuring proper cable performance and maintenance access.