The difference between bridge and trunking

About Bridge

The cable tray is divided into slot type, tray type, ladder type, mesh type, and other structures, consisting of brackets, brackets, and installation accessories. It can be erected independently or attached to various buildings (structures) and pipe rack supports, reflecting the characteristics of simple structure, beautiful appearance, flexible configuration, and convenient maintenance. All parts need to be galvanized and installed on the outdoor bridge outside the building. If it is located near the seaside or in a corrosive area, the material must have anti-corrosion, moisture resistance, good adhesion, and high impact resistance characteristics.

A bridge is a bracket that supports and places cables. Bridge trays are commonly used in engineering, as long as cables are laid, they must be used. As a supporting project of wiring engineering, cable trays do not have specific specifications and guidance. The specifications and programs of various manufacturers lack universality. Therefore, the design and selection process should be based on the type and quantity of cables in each weak current system, and the appropriate bridge tray should be reasonably selected. Cable trays have the characteristics of complete variety, wide application, high strength, light structure, low cost, simple construction, flexible wiring, installation standards, and beautiful appearance.

Classification of cable trays: stepped cable trays, tray type cable trays, trough type cable trays, and large span cable trays.

About Trunking

Cable trough, also known as wiring trough, wiring trough, or wiring trough (depending on the location), is used to organize power cables, data cables, and other wires in a standardized manner and fix them to electrical appliances on walls or ceilings. There are generally two types of materials, plastic and metal, which can play different roles.

The wiring duct is divided into: insulated wiring duct, split type wiring duct, mini type wiring duct, separated type wiring duct, indoor decoration wiring duct, integrated insulated wiring duct, telephone wiring duct, Japanese telephone wiring duct, open wire wiring duct, circular wiring duct, exhibition partition wiring duct, circular floor wiring duct, soft circular floor wiring duct, cover type wiring duct, etc. According to the different materials, the trunking is divided into various types, commonly used including environmentally friendly PVC trunking, halogen-free PPO trunking, halogen-free PC/ABS trunking, steel aluminum and other metal trunking, and so on.

Trunking characteristics: suitable for large span installation, extremely convenient installation, extremely safe and reliable, flexible wiring, and strong interchangeability.

The difference between bridge and trunking

1. The size specifications vary. The bridge is relatively large (200 × 100 to 600 × 200), with relatively small trunking. If there are many cables and wires, it is recommended to use a bridge.

2. The material thickness varies. According to JGJ16-2008-5.1, metal trunking, also known as trough type cable trays, is generally a trough type component formed by bending a whole sheet of steel plate with a thickness of 0.4-1.5mm. The conceptual difference between it and cable trays is that the height to width ratio is different, the tray frame is shallow and wide, and the metal trunking has a certain depth and closure. But the cable tray is more sturdy than the cable tray, and it is more used to accommodate cables, and of course, it can also accommodate wires, usually for strong current systems.

3. The filling rate varies. According to JGJ16-20088.5.3, the total cross-section of wires and cables in the trunking should not exceed 20% of the cross-section inside the trunking, and the number of current carrying conductors should not exceed 30. The total cross-section of cables in the bridge should not exceed 40% of the cross-section. This is due to different installation heights. When the installation height is low, a cover plate is necessary. If there is a cover plate, heat dissipation is not good, and the filling rate is lower.

4. Different sealing properties. The metal trunking is well sealed and does not need to be supported by brackets. It can be laid in cable trenches and building mezzanine layers. Some trough type cable trays are semi open and must be supported by brackets, which are usually installed in the air inside or outside the house.

5. Different intensities. The cable tray is mainly used for laying power cables and control cables, and the strength of the trunking is relatively low. It is usually used for laying wires and communication cables, such as network telephones.

6. The turning radius is different. The turning radius of the cable tray is relatively large, and most of the trunking turns at right angles.

7. Different spans. The span of the bridge is relatively large, and the trunking is relatively small. Therefore, there is a significant difference in the number of fixed supports and hangers.

8. The spacing between supports and hangers is different. According to JGJ16-2008, the length of the trunking is not greater than 2m, and the length of the cable tray is 1.5-3m.

9. Different installation methods. The bridge has special specifications (see CECS31.91 for details), while the trunking has no special Gauge fixing for fixing.

10. Cover plate issue. In CECS31 "Design Specification for Steel Cable Tray Engineering", the definition is that the tray is a collective term and the cover plate is an accessory. As mentioned in JGJ16-20088.10.3, when the installation height of the tray cannot meet the requirements, cover plate protection should be added. That is to say, the definition of the term bridge does not include cover plates. However, in GB29415-2013 "Fire-resistant Cable Tray Boxes", the cable tray contains a cover plate and is an integral part of the cable tray.