Knowledge of grooves, pipes and bridges that must be mastered - Weiwu

Specifications and varieties of grooves and laying of cables

In addition to cables, grooved pipe is an important part of wiring system. It can be said that metal groove, PVC groove, metal pipe and PVC pipe are the basic materials of integrated wiring system. In general wiring system, there are several situations in which the slot is mainly used: one is groove, the other is groove, groove, groove, groove, groove, groove, groove, groove and groove.

1) Metal grooves and accessories;

2) Metal pipes and accessories;

3) PVC plastic tank and accessories;

4) PVC plastic pipes and accessories.

Metal and plastic grooves

Metal trough is composed of trough bottom and trough cover. The length of each trough is 2 meters. When the trough is connected with the trough, the corresponding sizes of iron plate and screw are used to fix the trough. The shape of the groove is shown in the figure.

The specifications of metal grooves commonly used in integrated wiring systems are: 50 *100 mm, 100 *100 mm, 100 *200 mm, 100 *300 mm, 200 *400 mm and so on.

The appearance of the plastic tank is similar to the figure, but it has more varieties and specifications. From the model, there are: PVC - 20 series, PVC - 25 series, PVC - 25F series, PVC - 30 series, PVC - 40 series, PVC - 40Q series, etc. In terms of specifications, they are: 20 x 12, 25 x 12.5, 25 x 25, 30 x 15, 40 x 20, etc.

The accessories matching with PVC groove are: positive angle, negative angle, right turning angle, flat three-way, left three-way, right three-way, connection head, terminal head, junction box (dark box, bright box), etc.

Metal and plastic pipes

Metal pipes are used for branching structures or buried lines, and their specifications are also varied, with mm as the unit of outer diameter: the commonly used metal pipes in engineering construction are: D16, D20, D25, D32, D40, D50, D63, D25, D110 and other specifications.

It is more difficult to wire in metal pipe than in wire groove. When choosing metal pipe, we should pay attention to the selection of pipe diameter. In general, fillers in the pipe account for about 30% in order to facilitate wire crossing. Another kind of metal pipe is a hose (commonly known as a moth tube), which can be used in bending places.

Plastic pipe products are divided into two categories: PE flame retardant conduit and PVE energy retardant conduit.

PE flame retardant catheter is a kind of plastic semi-rigid catheter. It has D16, D20, D25 and D32 4 specifications according to its outer diameter. Appearance is white, with high strength, corrosion resistance, good flexibility, smooth inner wall and other advantages, both light and dark threading, it is also a unit of discs, each weight of 25 kg.

PVC flame retardant duct is a rigid duct extruded by processing equipment with polyvinyl chloride resin as the main raw material and appropriate additives. Small diameter PVC flame retardant duct can be bent at room temperature. User-friendly, according to external diameter: D16, D20, D25, D32, D40, D45, D63, D25, D110 and other specifications.

Accessories for installation of PVC pipes include: joints, coils, elbows, elbow springs; one-way connection, two-way connection, three-way connection, four-way connection, open pipe clamp, special pipe cutter, PVC rough mixture, etc.

Bridge frame

Bridge frame is a term used in cabling industry and an indispensable part of cabling in buildings. The bridge is divided into ordinary type, heavy type and trough type. Ordinary bridge can also be divided into ordinary bridge, straight-side ordinary bridge.

In the ordinary bridge frame, there are the following main accessories for combination:

Ladder, bend, three-way, four-way, multi-section two-way, convex bend, concave bend, elevation plate, end-to-end connection plate, width adjustment plate, vertical corner connection, connection plate, small flat corner connection plate, isolation plate, etc.

There are the following main fittings for combination in the through ordinary bridge frame:

Ladder, bend, three-way, four-way, multi-section two-way, convex bend, concave bend, cover plate, bend cover plate, three-way cover plate, four-way cover plate, convex bend through cover plate, concave bend through cover plate, flower hole tray, flower hole four-way tray, vertical corner connection plate, small flat corner connection plate, end-to-connection plate protection wrench, isolation plate, width adjustment plate, end baffle, etc.

Cable laying of grooves and pipes

1. Combination of cable tray or groove with pre-buried pipeline

1. Cable bridge should be 2.2 m above the ground, the top of the bridge should not be less than 0.3 m from the roof or other obstacles, the width of the bridge should not be less than 0.1 m, and the filling rate of the cross section in the bridge should not exceed 50%.

2. When laying the cables vertically in the cable bridge frame, the upper end of the cable should be fixed on the support of the bridge frame at about 1.5 m interval; when laying horizontally, it should be fixed at the head, tail and corner of the cable at 2-3 m interval.

3. Cable groove should be 2.2m above ground level. When setting in the ceiling, the opening surface of the slot cover should keep a vertical clearance of 80 mm, and the utilization ratio of the slot section should not exceed 50%.

4. Horizontal wiring, the cables laid in the groove can not be tied, the cables in the groove should be straight, as far as possible not cross, the cables should not overflow the groove, in the cable in and out of the groove, the bend should be tied and fixed. Vertical groove laying cables should be fixed on the cable bracket at 1.5 m intervals.

5. When laying wires in horizontal, vertical bridges and vertical grooves, the cables should be tied up. The bonding spacing should not be greater than 1.5 m. The buckle spacing should be uniform and moderate.

The embedded steel pipe is shown in the figure, which is combined with the location of the wiring groove.

2. Support protection mode of embedded metal wire groove

1. Embedded grooves in buildings can be arranged according to one or two layers according to different sizes. At least two grooves should be embedded, and the section height of the grooves should not exceed 25 mm.

2. When the length of the groove is more than 6 m or the groove route is crossed or transformed, the cable box should be set up to facilitate the laying of cables and maintenance.

3. The cable-drawing box cover should be open and level with the ground. Waterproof measures should be taken at the box cover.

4. Metal pipes should be used in the groove to lead into the distributor box.

5. The way of embedding metal wire groove is shown in the figure.

3. Supporting and Protecting Ways of Embedded Undercover Pipe

1. Metal pipes should be used for covert pipes. The inner diameter of covert pipes embedded in the middle of the wall should not exceed 50 mm. The inner diameter of covert pipes in floor should be 15-25 mm. Darkboxes and other devices should be installed at 30 m of straight line piping.

2. The turning angle of the concealed pipe should be greater than 900C. There should be no more than two turning points per concealed pipe in the path, and there should be no S-bending. When bending pipes, dark cabinet and other devices should be installed at 15 m interval.

3. The radius of curvature should not be less than 6 times of the outside diameter of the dark tube. If the outside diameter of the dark tube is greater than 50 mm, it should not be less than 10 times.

4. The nozzle of the dark tube should be smooth with insulating sleeve. The nozzle should extend 25-50 mm. The requirement of the extension part of the orifice is as shown in the figure.

4. Protective Ways of Combination of Lattice Groove and Groove

1. The groove and the lattice groove must be communicated.

2. The groove cover can be opened and level with the ground. Waterproof measures should be taken at the outlet of the cover and socket.

3. The width of groove should be less than 600 mm.

4. The composition of the lattice groove and groove is shown in the figure.

5. When laying cables on movable floor, the clearance in movable floor should not be less than 150 mm. If the movable floor is used as a ventilation duct, the net height in the floor should not be less than 300 mm.

6. When using public pillars as ceiling support, cables can be laid in the pillars. The support points of the pillars should avoid grooves and slots, and the support should be firm. The wiring method of the public post is shown in the figure.

7) When different kinds of cable wiring are placed in the metal slot, they should be separated from the slot (separated by metal plate). The grounding of metal grooves should meet the design requirements.

The cable laying support protection of trunk subsystems shall meet the following requirements:

! Cables shall not be placed in elevators or pipeline shafts.

! Communication should be conducted between trunk routes.

! Cables in the shaft should be rectangular or circular through holes in each floor. The size of rectangular holes should not be less than 300 *100 mm; at least three circular steel tubes should be installed at the circular holes, and the diameter should not be less than 100 mm.

8) In the case of uncertain information point location and cable laying mode in the work area, or when cables are laid under carpets in the work area, it is advisable to set up handover boxes in the work area, each of which has a service area of about 80 cm2.

Requirements for protection of cable bridge and cable groove support are set up.

1. When the bridge is laid horizontally, the spacing between supports is generally 1-1.5 M. When the bridge is laid vertically, the spacing fixed on the building should be less than 1.5 m.

2. When laying metal slots, brackets or hangers should be set up in the following situations: slot joints; spacing 1-1.5 m; 0.5 m away from the two ends of slots; turning corner.

3. The distance between fixed points at the bottom of plastic groove is generally 0.8-1 M.

PS: Weak current updates quickly. Everyone of us has to keep learning, but some experiences and methods will be passed on. Welcome all the project bosses and colleagues to pay attention to Jun Primary School and discuss the weak current technology scheme and engineering projects.