NEC (National Electrical Code) Article 300. 3 (C) (1): Prohibits the mixing of power and low-voltage cables (e., control, communication) in the same raceway or tray unless specific separation or shielding requirements are met. These systems provide an efficient and adaptable solution for managing a wide range of cables, including power cables, control cables, Ethernet, and fiber optic lines. Cable tray is the preferred wiring method for industrial facilities, data centers, and large commercial buildings where routing dozens or. Since cable tray is not defined as a raceway, would NEC 300. 20 (A) is pretty generic in stating that all multiconductor cables operating at 1000V or less can be installed in the same tray.