Cable Tray Arrangement & Installation Specifications

Cable trays shall be arranged from top to bottom as follows: Computer Cable Trays, Shielded Cable Trays, Master Control Cable Trays, Low-Voltage Power & Lighting Cable Trays, and High-Voltage Cable Trays. If two cables of different purposes need to be placed in the same tray, an intermediate partition shall be installed to separate them, and the tray shall be covered with a plate.

For ease of maintenance and installation:

The total width of trays on the same floor shall not exceed 2m.

The distance between adjacent tray layers shall generally be 300mm.

The distance from the side of a cable tray to the wall shall be 50-100mm.

The distance between edges of horizontally adjacent trays shall be 50mm.

Hot-Dip Galvanized cable trays

The distance from the bottom of a vertically installed cable tray to walls or columns shall be 25-50mm.

The distance from the top of the tray to the bottom of obstacles such as ceilings or beams shall be greater than 150mm.

If the distance between the bottom of the tray and the top of electrical equipment is less than 450mm, a non-combustible partition shall be installed at the bottom of the tray.

The spacing between supports of Hot-Dip Galvanized Cable Trays shall generally be less than 3m; 1.5m or 2m is commonly adopted in actual projects.

Expansion bolts are typically used to fix tray arms and columns. The setting strength of fixed positions shall be determined by calculation.

To avoid drilling into steel reinforcement, a reinforcement detector can be used for pre-inspection. Main reinforcement bars shall be avoided as much as possible.

Where supports are used in cable trenches or tunnels, embedded parts shall be adopted instead of expansion bolts.

Embedded parts are generally made of flat steel with a thickness of 8-16mm and a width of 80-200mm, and the support arms are directly welded to the flat steel.