Size conductors installed in cable tray with NEC 392, NEC 310. 16, tray fill, ampacity adjustment, voltage-drop checks, grounding, and IEC design cross-checks. Cable tray systems provide a safe, organized, and flexible method for supporting insulated conductors and cables in commercial and industrial electrical installations. Tray fill, spacing, ambient temperature, and sun exposure. us-trations without notice. All illustrations, descriptions and technical information included in this document are provided as indications and can cable trays are equivalent.