With the vigorous development of the real estate industry in China, intelligent building as a new development hotspot has promoted the development of the weak electricity industry. However, the current weak electricity construction specifications are still not perfect, and there are often some problems in the weak electricity construction. Xiaobian has summarized it here.
Weak electricity construction common problems
Weak electricity construction has relevant standards and specifications, and a qualified weak electricity construction team should also be mastered. However, when it comes to the project, there will be some minor problems, which are also common problems in weak electricity construction:
1. In the construction of weak electricity, the construction unit pays attention to the use function of each subsystem and neglects the sensory acceptance, that is, the phenomenon that may occur is that the wiring does not live up to expectations, the information panel is disorderly arranged, and there is no sign.
2. During the construction of weak current, the installation of the cabinet is often neglected. The installation of the cabinet should be stable and firm. It should be reinforced according to the guidelines of the construction drawing, but it is often ignored in actual construction.
3. When the strong and weak electric cables are laid in parallel or crosswise, the spacing is less than 0.3m. When the communication line is parallel or cross-connected with other weak wires, the spacing is less than 0.1m. This is strictly prohibited in the specification. of.
4. The laying of weak electric cables is not straight, resulting in twisting, ringing, etc. Some cables are squeezed and damaged by external forces.
5, through the floor bridge without the use of fire mud or no block at all.
6. The weak electric piping for outdoor burial is laid with PVC pipes, while the weak electric construction specifications emphasize the use of steel pipes.
7. Fire-fighting weak electricity, the horizontal distance between the detector and the wall and the beam edge is less than 0.5m.
8. The low-voltage circuit in the lower part of the movable floor in the equipment room does not use copper-core shielded wire or copper-core shielded cable. The distance between the power cable and the weak signal line is not enough, and sometimes there are cases of laying side by side.
9. The pressure equalization ring in the equipment room is not grounded.
10. Weak electricity construction often neglects the installation of surge absorbers on the low-voltage busbars in the dedicated distribution box of the mainframe. The surge absorber must have the national Ji test report.
Â
Â
Weak wiring construction considerations
1. When the signal cable (line) crosses the power cable, it should be at right angles; when paralleled, the distance between them should meet the design requirements.
2. Cables with different signals and different voltage levels in the same trunking should be classified and arranged; for AC power lines and interlocking lines, the application partitions should be laid separately from the unshielded signal lines.
3. When the cable is laid along the bracket or in the line slot, it should be fixed firmly in the following places: (1) When the cable slope is more than 45° or vertically arranged, it is on each bracket. (2) When the slope of the cable is not more than 45° and horizontally arranged, it is on every 1~2 brackets. (3) and compensate the margin on both sides and the first and second brackets on both ends of the protection tube. (4) Introduced 300 to 400 mm in front of the instrument panel (box). (5) Introduce the junction box and the junction box 150 to 300mm.
4. When the trunking is installed vertically, the cables shall be arranged from top to bottom in the following order: instrument signal lines; safety interlock lines; AC and DC power supply lines;
5. The clear distance between the signal line laid by Ming and the electrical equipment with strong magnetic field and strong electric field should be greater than 1.5m; when using shielded cable or metal protection tube and laying in the wire trough, it should be greater than 0.8m.
Weak lightning protection grounding construction precautions
1. The grounding of the weak current system is divided into protective grounding and functional grounding according to the purpose. Protective grounding is divided into: anti-shock grounding, lightning protection grounding, anti-static grounding and anti-corrosion grounding; functional grounding is divided into: working grounding, logic grounding, shielding grounding and signal grounding. Different groundings have different requirements and should be grounded as determined by design.
2. The grounding device of the weak current system that needs to be grounded should meet the following requirements:
(1) When the piping is made of galvanized electric pipe, the pipe and the pipe, the pipe and the metal box do not need to be connected after the connection is specified, but the following requirements shall be observed:
1) When the pipe is threaded, the length of the pipe end thread should not be less than 1/2 of the length of the pipe joint. The thread surface should be smooth, free from rust and defects. The thread should be coated with electric compound or conductive anti-corrosion grease. After connecting, the thread should be exposed with 2~3 buckles.
2) When the pipe is connected by a sleeve with a set screw, the screw should be tightened; in the vibration place, the set screw should have anti-loose measures.
3) The connection between the pipe and the box should not be made of plastic, and the conductive metal should be used.
4) When there is a PE wire in the weak current pipe, each junction box should be connected to the PE wire.
(2) When the piping is made of galvanized electric pipes and the design requires that the pipes need to be bridged, the following provisions shall be observed:
1) The tube should not be welded by welding, and the special next-line clamps specified by the design should be used for bridging.
2) The electric pipe buried or buried in the concrete can be bridged by welding without applying a line card.
3) If a bare soft PE copper wire is worn inside the pipe, the electric pipe may not be bridged. This PE wire must be connected to each junction box it passes through.
(3) When the piping is made of black iron pipe, if the design does not require bridging, it is not necessary to bridge. If bridging is required, round steel joints between black iron pipes and black iron pipes and junction boxes can be used, single-sided welding, bridging length should not be less than 6 times the diameter of spanning round steel; black iron pipe and plating When bridging between zinc bridges, a copper bolt shall be welded at the end of the black iron pipe, and a copper wire of not less than 4 mm shall be connected to the galvanized bridge.
(4) When the PVC pipe is used for both strong and weak electricity, in order to avoid interference, the weak electric piping should be avoided to be laid in parallel with the strong electric piping. If it must be laid in parallel, the distance should be more than 0.5m.
(5) When the strong and weak electric power line is laid, the strong and weak electric wire slots should be separated; when it is required to be laid in the same trunking, the strong and weak electricity should be separated by a metal partition.
Steel Wire Reinforced UHMWPE Pipe
We use a new process of "adhesive-free interference compound", That is to make the outer diameter of the UHMW-PElining pipe larger than the inner diameter of the steel pipe, and then the UHMW-PE pipe diameter is reduced by mechanical shrinkage, and the plastic lining pipe is introduced into the steel pipe without adhesive, andthe UHMW-PE ultra-strong memory function is utilized to stand for 24 to 48 hours, so that the UHMW-PE lining pipe isfirmly adhered to the inner wall of the steel pipe.
Steel Wire Reinforced Uhmwpe Pipe,Steel Wire Wound Uhmwpe Pipe,Water Supply Pipe,Steel Wire Reinforce Hdpe Pipe
Shandong Eastern Pipe Co., Ltd. , https://www.dfuhmwpe.com