Abstract :
The presently available rules for prescribing ampacities of cables in trays have been found unduly restrictive for light to medium tray loading, leading to wide disregard of such derating for all loadings. Here is presented a method, founded on sound heat-transfer technology, and experimentally verified, for such ampacity determination. Its use should restore user confidence, with realistic ratings dependent on tray fill, and eliminate the serious consequences of tray cable overloading.
