1. For indoor cable trays, the short span distance for supports and hangers is generally 1.5-3m. For outdoor columns, the medium span distance is generally 6m.
2. The configuration of supports and hangers for non-straight sections should follow these principles: When the cable tray width is 300mm, in addition to meeting the following conditions, an additional support or hanger should be installed in the middle of the non-straight section.
3. When cable trays are installed in multiple layers, the center-to-center distance between layers should be 200, 250, 300, or 350mm.
4. An expansion joint of 20-30mm should be provided every 50m for straight sections of cable trays (for metal cable trays).
5. Sections of cable trays requiring fire resistance must be made of steel or non-combustible or flame-retardant materials.
