This design note adopts a 300 mm horizontal air-gap separation between primary and secondary life-safety trays on roofs, based on these regulatory requirements and established UK guidance. BS 7671:2018 +A2:2022 states: “Circuits of safety services shall be independent of other. maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. A rung spacing of 6 to 9 inches (150 to 230 mm) is preferable when the cable tray cont d for instrumentation and control applications that require. Cable tray spacing is a critical aspect of electrical infrastructure, influencing both safety and efficiency. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned in this technical guide only apply to our own cable management ranges and cannot under any circumstances be transposed to si osure, overheating or. Cable trays play a vital role in supporting electrical cables and wires in commercial, industrial, and utility installations. For proper installation, design, and maintenance, adherence to international standards is essential. One of the most recognized frameworks globally is the IEC standard for. UK electrical and fire safety standards do not prescribe a fixed minimum separation distance for roof-mounted life-safety cable trays.