1. Processing and laying of cable pipes:
(1) The metal cable pipe should not have perforation, crack, significant uneven and serious corrosion, and the inner wall of the pipe should be smooth without burr. Cable pipe should not crack or significant concave phenomenon after bending, bending degree is not more than 10% of the pipe diameter, pipe mouth should be made into a horn or polished.
(2) The inner diameter of the cable pipe should not be less than 1.5 times the outer diameter of the cable, and the bending radius should conform to the bending radius of the penetrating cable. Each cable pipe should not exceed three elbows. There should be no more than two right angles.
(3) The connection of cable pipes shall meet the following requirements:
A, metal pipe should be connected with a large short pipe sleeve, both ends of the short pipe welded tightly sealed, connected with a wire buckle, the connection is well sealed.
B, when the metal tube is inserted or inserted, the insertion depth should not be less than 1.1 ~ 1.8 times of the inner diameter, and the insertion surface should be coated with cement to adhere and seal. When using socket, both ends of the casing should be sealed and welded to ensure firm and sealed.
C. Thin wall steel pipe is strictly prohibited from being fused.
(4) when a thin-walled steel pipe is used as a cable pipe, it should be coated with anti-corrosion paint on the surface (the pipe embedded in concrete can not be painted); ​when galvanized pipe is used, the peeling place of galvanized layer should also be coated with anti-corrosion paint.
(5) The position of the cable pipe leading to the equipment should be easy to connect the equipment and not hinder the disassembly and access of the equipment. Parallel cable pipe openings should be arranged neatly.
(6) When the protective pipe of the cable is used as the ground wire, the ground wire should be welded first before laying the cable. Jumpers should be welded at the pipe joints with wire buckles.
(7), the tube into the box (box) to straight, in the box (box) exposed length is equal to or less than 5 mm, fixed with lock nut pipe, pipe exposed lock nut thread for 2 ~ 4 buckles.
2. Preparation and installation of cable bridge:
(1) Cable tray and accessories should be properly stored and kept, should not cause deformation and damage, and there should be a solar cable supplier product certificate.
(2) The cable tray should be firmly installed, horizontal and vertical, its vertical deviation should not be greater than 2/1000 of its length, and its horizontal error should not be greater than 2/1000 of its width.
(3) Cable bridge in the production of non-standard parts and welding, must be coated with anti-corrosion primer, finish paint should be uniform and complete, the color difference is consistent.
3. Cable laying:
Process: Material 1 transportation, storage -- cable pipe laying and cable bridge installation -- insulation resistance test before cable installation -- cable laying.
(1) Before cable laying, the completeness of the bridge and the integrity of the paint should be checked. The cable model, voltage and specification should meet the design and have the product certificate.
(2) When the cable is laid, the spare length should be left in the terminal and cable bridge or cable trench.
(3) When the cable is laid vertically on the bridge, the head end of the power cable and the turning and the ends of the joint should be fixed.
(4) The bending radius of plastic insulated cable is not less than 10 times the cable diameter.
(5) When the cable is laid, the cable should be led out from the upper end of the plate, and the friction and dragging of the cable on the support and the ground should be avoided. There should be no mechanical damage on the cable surface.
(6) Cable laying should not be crossed, cables should be arranged neatly, cable terminal head, cable connection, both ends of the cable well should be installed with signs, signs should indicate the line number (when the design is not numbered, it should indicate the model, specifications and start and end place), the brand writing should be clear, not easy to fall off. The specification of the sign should be unified, should be able to prevent corrosion and hang firmly.
(7) When the cable enters the cable trench, building, tray (cabinet) and enters the pipe, the entrance and exit should be closed, and the pipe mouth should be sealed.
(8) The cable terminal head and cable joint should be checked before making, to ensure that the phase is correct, and the insulation material should meet the requirements.
4. Wiring project:
Procedure: piping - pipe threading
1) This project is dark distribution pipeline, dark applied in the decoration of combustible material ceiling, bright applied in wet places or buried lines should use metal pipe wiring, open or dark applied in dry places lines can use PVC wire pipe. Ac lines through metal pipes shall not be laid in the same pipe for different circuits, and shall not be laid separately for the same circuit. The SPACING OF fixed POINTS WHEN METAL pipes are LAID OUT, and the clear spacing when laying and crossing with other pipes on the same side shall meet the construction code and design requirements.
When the pipeline line is long, it is advisable to install an appropriate junction box. The line part shall not exceed 30m, one bend shall not exceed 20m, two bends shall not exceed 15m, and three bends shall not exceed 8m.
After the metal pipe is laid, the number of roots, pipe diameter and starting point should be checked, and the missing ones and those that do not meet the requirements of the drawings and current construction specifications should be repaired.
2) Pipe threading should be carried out after the plastering and ground work of the building is finished. Before threading, the water and debris in the pipe should be removed. The conductor shall not have joints and kinks in the pipe, and the joints shall be connected in the junction box.
3) After the wire is put into the steel pipe, the mouth guard should be installed at the outlet of the wire to protect the wire, and the vertical pipe mouth in the box (box) should be used as a sealing place after it is put into the wire.