The Role of Bridge Tray in Power System 

Bridge Tray (Cable Tray) is the key infrastructure for cable laying in power system, which is mainly used to support, protect and manage power cables to ensure the safety, reliability and high efficiency of power transmission. Its role in the power system is mainly reflected in the following aspects: 

1. Cable support and protection 

Mechanical protection: to prevent the cable from damage due to gravity, vibration or external forces (such as stepping on, extrusion).

Environmental protection: 

Dust and moisture resistance (closed channel bridge is suitable for humid or dusty environment).

Anti-corrosion (galvanised steel, stainless steel or FRP bridges are suitable for chemical, marine and other corrosive environments).

Fireproof (metal bridge is more resistant to high temperature than plastic trunking, with fireproof coating can enhance the fire resistance level).

2. Optimise cable heat dissipation 

Open type bridge (ladder type, mesh type) can effectively dissipate heat, avoiding overheating of cables resulting in: 

Insulation deterioration, increased risk of short-circuit.

Decrease in load capacity (high temperature environment can reduce the power transmission capacity of the cable by 20% to 30%).

Enclosed bridges (trough type) need to be designed with ventilation or used in low-temperature environments.

3. Improve power system reliability and maintenance convenience 

Faster troubleshooting: open bridge is easy to check cable status and quickly locate broken or overheated points.

Flexible expansion: when upgrading the power system, there is no need to break the wall and bury the pipe, and additional cables can be laid directly in the bridge.

Reduce electromagnetic interference: metal bridge can provide a certain shielding effect, reduce the interference of strong power on weak power (such as control signal lines).

4. Adaptation to different power scenarios 

Power Application Scenarios Recommended Bridge Types Advantages 

Substation/Distribution Room Heavy-duty galvanized steel ladder type bridge Strong load carrying capacity, fireproof and high temperature resistant 

Factory Power Cable Tray or ladder type bridge Good heat dissipation, suitable for high-current cables 

Underground Cable Corridors Corrosion-resistant stainless steel or glass fiber reinforced plastic (FRP) bridge Moisture-resistant, chemical corrosion-resistant 

Data Center Distribution Grid-format Bridge (+ fiber optic troughs) Lightweight, high heat dissipation, support for High-density cabling 

Outdoor power engineering Hot-dipped galvanised steel bridges Weather-resistant, UV-resistant 

5. Key standards for bridges in the power system 

National standards: 

GB/T 19215 (cable trunking system for electrical installations) 

GB 50217 (cable design specification for electric power engineering, which stipulates requirements for the selection and installation of bridges) 

Industry specifications: 

Bridge filling ratio ≤ 40% (to avoid overheating of cables).

High-voltage cables and weak power cables need to be laying in layers or racks (anti-interference).

6. Comparison of bridge vs. traditional power laying methods 

Comparison Items Bridge Buried Pipe Overhead Line 

Installation Cost Medium High (need to excavate and backfill) Low (but subject to environmental constraints) 

Maintenance Difficulty Low (open and easy to overhaul) High (faults need to be broken down) Medium (need to work on the heights) 

Heat dissipation Superior Poor Superior 

Applicable Voltage Levels Low Voltage~High Voltage (common under 35kV) Low Voltage~Medium Voltage High Voltage Transmission (110kV+) 

Summary: Bridging in the The core value of bridge in power system 

Safety: physical protection + fire anti-corrosion, prolonging cable life.

Efficient: Optimise heat dissipation, enhance cable current-carrying capacity.

Economy: Reduce long-term maintenance costs and adapt to capacity expansion needs.

Compliance: comply with power engineering specifications, to ensure system stability.

In modern power systems, bridge has become the preferred solution for cable laying, especially suitable for industrial power distribution, substations, data centres and intelligent buildings and other scenarios.