Step Bridge

What are the key installation points for ladder cable trays?

1. The routing of ladder cable trays and wireways should be short and direct, preferably along walls, columns, or beams.

2. Based on the installation path of cable trays and wireways, the civil and structural engineering teams should specify the locations and load requirements for reserved wall openings, floor openings, and embedded steel plates for hanger installation. Coordination with process engineering, plumbing, and electrical disciplines is essential.

3. The wiring design for underground concealed metal wireways must be closely coordinated with civil engineering, with routes and equipment selection rationally determined according to structural types and building layouts.

4. Cables of different voltages and purposes should not be installed on the same layer of a cable tray:

(1) Cables above 1kV and below 1kV;

(2) Dual-circuit cables supplying power to primary loads on the same path;

(3) Emergency lighting and other lighting cables;

(4) Power, control, and telecommunication cables. If cables of different ratings are installed in the same cable tray, a partition should be added in between for isolation.

5. When no additional concentrated loads are considered for installation or maintenance under engineering conditions, the working uniformly distributed load of the ladder cable tray should be calculated based on the even distribution of cable weight.

6. Ladder cable trays should not be laid parallel to the following pipelines. If unavoidable, the position of the cable tray must meet the following requirements, or corresponding protective measures should be taken.

(1) Cable trays should be above corrosive liquid pipelines.

(2) Cable trays should be below thermal pipelines.

(3) When flammable and explosive gases are heavier than air, cable trays should be above the pipelines.

(4) When flammable and explosive gases are lighter than air, cable trays should be below the pipelines.

(5) The minimum distance between cable trays and pipelines should comply with relevant standards.

(6) A necessary distance should be maintained between integrated wiring cables and electrical equipment that may generate high-level electromagnetic interference (such as motors and power transformers). The spacing between integrated wiring cables and power cables should meet relevant regulations.

(7) The distance between integrated wiring cables, optical cables, and conduits installed on walls and other pipelines should comply with relevant regulations.