电气工程里，桥架常被当成“铁皮盒子”凑数，真到验收阶段，发热、下垂、锈蚀、接地不通，全卡在选型细节上。

In electrical engineering, cable trays are often treated as "metal boxes" to make up for numbers. When it comes to the acceptance stage, heating, sagging, rusting, and grounding are all stuck in the selection details.

先按场景定结构：

First, structure according to the scene:

弱电、通信、消防控制回路：槽式带盖，防尘防干扰；

Weak current, communication, and fire control circuits: trough type with cover, dust-proof and anti-interference;

厂房动力主干、大截面电缆：梯级式，散热好、自重轻；

Factory power backbone and large section cable: cascade type, good heat dissipation, light weight;

动力与控制混敷：托盘式，带孔底板兼顾散热与防护；

Hybrid power and control: tray type, perforated bottom plate that balances heat dissipation and protection;

机房、吊顶上走线：网格式或铝合金走线架，扩容方便。

Wiring on the computer room and ceiling: grid format or aluminum alloy cable rack, easy to expand.

环境决定材质与防腐：

Environment determines material and anti-corrosion:

室内干燥：电镀锌够用；

Indoor drying: sufficient for galvanizing;

地下室、户外、管廊：热浸锌，锌层≥65μm，潮湿环境提到85μm以上；

Basement, outdoor, pipe gallery: hot-dip galvanizing, zinc layer ≥ 65 μ m, humid environment above 85 μ m;

化工、沿海：锌铝镁、304/316L不锈钢或玻璃钢；

Chemical and coastal industries: Zinc aluminum magnesium, 304/316L stainless steel or fiberglass;

消防回路：防火槽盒，要对应耐火时限的检测报告，别拿普通喷塑顶替。

Fire protection circuit: Fireproof trough box should have a corresponding fire resistance test report, do not replace it with ordinary spray paint.

厚度跟着跨距走。支吊架间距2m时，宽300mm内底板≥1.2mm，300–600mm≥1.5mm，大跨距或重载继续加厚。采购单写“实厚”，到货用卡尺抽检，防“标厚货薄”。

The thickness follows the span. When the spacing between supports and hangers is 2m, the bottom plate within a width of 300mm should be ≥ 1.2mm, and 300-600mm should be ≥ 1.5mm. For large spans or heavy loads, the thickness should continue to increase. Write 'solid thickness' on the purchase order, and use calipers to conduct spot checks upon arrival to prevent' thick and thin goods'.

安装端三件事不能省：

Three things that cannot be saved during installation:

直线段超30m设伸缩节，变形缝必装补偿装置，螺栓留伸缩余量；

Expansion joints shall be installed for straight sections exceeding 30m, and compensation devices shall be installed for deformation joints. Expansion allowance shall be reserved for bolts;

金属桥架全长至少2处接PE干线，超30m每20–30m补一点，镀锌桥架连接端每端≥2颗防松螺栓；

At least 2 locations along the entire length of the metal bridge shall be connected to the PE main line. If it exceeds 30m, one point shall be added every 20-30m. At least 2 anti loosening bolts shall be installed at each end of the galvanized bridge connection;

弯通、三通、穿墙两侧加密托臂，严禁在穿楼板处做接头。

Bent joints, tees, and reinforced support arms on both sides of wall penetrations are strictly prohibited from making joints at floor penetrations.

填充率守住红线：动力电缆≤40%，控制电缆≤50%，留两成扩容空间。

Keep the filling rate at the red line: power cables ≤ 40%, control cables ≤ 50%, leaving 20% expansion space.

桥架是电缆系统的承重骨架，先算荷载和环境，再定板厚与防腐，后期才少返工。

The cable tray is the load-bearing skeleton of the cable system. The load and environment are calculated first, and then the plate thickness and anti-corrosion are determined to reduce rework in the later stage.