Smart home layout, wiring material characteristics and selection

PVC wire and pipe performance and selection

Home-installed electrical engineering is commonly used PVC pipe and PVC bellows.

PVC electrical conduits are generally classified into four categories: ordinary PVC, PVC-U, PVC-P, and PVC-C.

PVC can be divided into soft PVC and hard PVC, in which hard PVC accounts for about 2/3 of the market, and soft PVC takes up 1/3. Soft PVC - generally used for the surface layer of the floor, ceiling and leather, but because soft PVC contains plasticizer (this is also the difference between soft PVC and hard PVC), the physical properties are poor (above the water pipe needs to withstand a certain pressure, soft PVC is not suitable for use, so its scope of use is limited.

1. Classification of PVC wire and pipe

PVC wire and tube can be divided into round tube, groove tube and corrugated tube according to tube shape.

PVC wire tube according to the thickness of the wall can be divided into light -205 (outside diameter is

PVC wire and tube can be divided into gray, white, yellow and red depending on the color.

2. Quality inspection of PVC wire and pipe

Home-installed wire and pipe should use high-quality, high-quality PVC wire and pipe. In the selection can be used to detect the quality of PVC wire and pipe, can also refer to the following check the quality of PVC wire and pipe.

(1) Flame retardant test. The open flames of the PVC wire and pipe were continuously fired 3 times, each time 25s, separated by Ss. After the PVC wire pipe was withdrawn from the fire source, it was qualified as self-extinguishing.

(2) Flattening test. Pass the elbow spring into the PVC pipe and bend the pipe to 90°. The bend radius is 3 times the pipe diameter, and the appearance of the bend should be smooth.

(3) Impact test. Tap with a hammer to strike no cracks (can be used for on-site inspections).

(4) The outer wall of PVC wire and pipe shall have continuous fire-retardant marks and manufacturer's marks with a spacing of not more than 1m.

(5) The manufacturer of PVC wire and pipe shall have a fire permit approved use permit.

3.PVC wire and pipe operation precautions

(1) When using a PVC wire tube for bending, a special spring should be inserted into the tube. During the test, the tube was bent to 90° and the bending radius was 3 times the diameter. After bending, the appearance should be smooth.

(2) When the length of the PVC electric conduit pipe exceeds the following length, a sub-box or enlarged pipe diameter shall be installed in the middle:

1 The total length of the pipe is more than 20m without any bending.

2 The total length of the pipe is more than 14m, only one bend.

3 The total length of the pipe is more than 8m and there are two bends.

4 The total length of the pipe is more than 5m and there are 3 bends.

(3) When pre-embedding PVC wire and pipe, it is forbidden to clamp and flatten the pipe mouth with a pliers, and apply a PVC plug fitting the pipe diameter to cover the pipe mouth and securely bind it with tape.

(4) When there is a connector on the line, a cassette must be left at the head, and the panel is buckled. It is convenient for future replacement and maintenance.

(5) When laying PVC conduits, the cross-sectional area of ​​the bus cannot exceed 40% of the inner diameter of the PVC conduit.

(6) Wires with different voltage levels and different signals must not be put in a PVC conduit to avoid mutual interference.