When installing two cable trays in parallel at the same height, the distance between them should be no less than 0. This spacing is crucial for adequate maintenance access, ease of inspection, and ensuring proper airflow for effective heat dissipation. 8 (Other Mechanical Stresses (AJ)) in that document provides requirements for cable support. Clause 522-08-04 Where conductors or cables are not supported. UK electrical and fire safety standards do not prescribe a fixed minimum separation distance for roof-mounted life-safety cable trays. However, BS 7671, BS 8519, and BS 5839 collectively establish that life-safety circuits must be installed on dedicated containment and be either separated by. The primary rulebook used in the safe use of cable trays is NEC Article 392. This is a description of how to select, install, and support these metal or plastic frames, on which electrical wires are installed.