What role do cable tray systems play in thermal management and maintaining cable ampacity?

Open cable trays permit continuous airflow around each cable, minimizing mutual heating effects that occur in enclosed conduit. This thermal advantage allows cables to operate closer to their rated current-carrying capacity as calculated by methods in IEC 60287, reducing the risk of insulation breakdown and premature aging. In high-density power distribution environments, such as data centers or heavy industrial switchrooms, the ventilation provided by ladder or perforated trays is essential for maintaining safe operating temperatures without forced cooling, thereby improving energy efficiency and extending service life.