Wiring method of Jiangmen Bridge
1) Admission direction: according to the construction layout plan, combined with the setting of air-conditioning pipelines and electrical pipelines, it is convenient to repair and the density of cable route to recognize the good route of Jiangmen bridge of Huixian line. Indoor, it should be erected along the wall, column, beam and floor of the building as far as possible. If the inductive pipe gallery is needed to be used, it should be erected in parallel above one side of the pipeline, and downlead should be considered The box branch lines shall be prevented from crossing as far as possible. If there is no other pipe support for borrowing, the support shall be set up by itself.
(1) when the cable is laid indoors, jute or other inflammable materials shall not be used as the outer protective layer of the cable.
(2) when cables are used in corrosive or wet places, corresponding protection measures should be adopted according to different corrosive media, and plastic sheathed cables should be selected.
(3) the height of horizontal equipment of cable bridge (tray) should not be less than 2.50M, and the metal cover should be kept below 1.80m of straight equipment, but should be laid in special electrical room (such as distribution room, electrical shaft, skill layer, etc.).
(4) when selecting the horizontal equipment of Jiangmen bridge, the best span should be selected according to the load curve. The span is generally 1.5-3m. When laying in straight line, the interval between fixed points should not be greater than 2m.
(5) when multiple groups of cable bridges are equipped with parallel equipment at the same height, the interval between adjacent cable bridges should be considered for protection and repair.
(6) the cable can be laid on the cable tray without separation. The filling ratio of the cross-section of the cable in Jiangmen bridge should not be greater than 40%, and that of the control cable should not be greater than 50%.
(7) when the cable tray is parallel to or intersects with various pipelines, its small clear distance shall comply with the rules in table dq4-1.
(8) the cable tray should not be installed above the corrosive gas pipeline, heat pipe and under the corrosive liquid pipeline, otherwise, the anti-corrosion and thermal insulation method should be adopted.
(9) the cables in the cable tray shall be fixed at the following parts. When laying in a straight line, the upper end of the cable shall be laid every 1.50-2m. When laying horizontally, the head end and tail end of the cable shall be turned every 5-10 meters.
Because if the bridge is not used, when the cable is kneaded, the two ends of the cable will be subjected to abnormal tension (hard end), and the center of the cable will be subject to a sag force. In order to ensure the uniform stress and long-term stability of the cable, it is necessary to use the bridge to separate the various forces of the cable, so as to ensure the safety and reliability of the cable.
Source: Jiangmen bridge pipe http://www.jmyxt.cn/