The International Electrotechnical Commission (IEC) provides detailed guidelines for cable tray systems under IEC 61537. This standard outlines the construction requirements, testing methods, and performance parameters for cable trays and related support systems. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned. The gap area between firestop packs and cables should not exceed 1 cm2, and the packing thickness should be not less than 24 cm. All gaps inside and around metal trunking must be sealed tightly and be complete both internally and externally. Cover plates should be square, of consistent suitable. Select the tray width and thickness according to the number and weight of cables.