Step Bridge

What are the key installation points for ladder-type cable trays?

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

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

3. The wiring design for underground concealed metal wireways must be closely coordinated with civil engineering, with route planning and equipment selection tailored to different structural types and building layouts.

4. Cables of different voltages and purposes should not be laid 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 classes are installed in the same cable tray, a partition should be added for isolation.

5. When additional concentrated loads are not considered for installation or maintenance under engineering conditions, the working uniformly distributed load of the ladder-type cable tray should be calculated based on the even distribution of cable weight.

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

(1) The cable tray should be above corrosive liquid pipelines.

(2) The cable tray should be below thermal pipelines.

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

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

(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 adhere to relevant regulations.

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