1. Processing and laying of cable pipe:
(1) The metal cable pipe should not be perforated, cracked, significantly uneven and serious rust, and the inner wall of the pipe should be smooth without burr. There should be no cracks or significant dents in the cable tube after bending. The bending degree should not be greater than 10% of the outer diameter of the pipe. The pipe mouth should be made into a horn or polished.
(2) The inner diameter of the cable tube should not be less than 1.5 times the outer diameter of the cable, and the bending radius should comply with the provisions of the bending radius of the cable. Each 6mm2 solar cable should have no more than three elbows. There should be no more than two right angles.
(3) The connection of cable pipe shall meet the following requirements:
a. It is advisable to use a large short pipe sleeve for metal pipes. Both ends of the short pipe should be welded tightly and sealed.
b. When metal pipes are inserted or inserted, the insertion depth should not be inferior than 1.1 ~ 1.8 times the inner diameter, and the connector surface should be cemented and sealed with adhesive. When the sleeve is used, both ends of the casing should be sealed and welded to ensure firm sealing.
c. The thin-walled steel pipe is strictly prohibited from fusion welding connection.
(4) When thin-walled steel pipe is used as cable pipe, anti-corrosion paint should be applied on the surface (pipe embedded in concrete can not be painted); when galvanized pipe is used, the peeling of galvanized layer should also be coated with anti-corrosion paint.
(5) The location of the cable pipe opening leading to the equipment shall be convenient for the connection of the equipment without hindering the disassembly and access of the equipment. Parallel cable pipe openings should be arranged neatly.
(6) When the protective tube of the cable is used as the grounding wire, the grounding wire should be welded first, and then the cable is laid. Jumpers should be welded at the pipe joints with wire connections.
(7) When the pipe enters the box (box), it should be straightened. The length exposed in the box (box) is equal to or less than 5㎜, and the pipe is fixed with the lock nut. The thread of the pipe exposed lock nut is 2 ~ 4 buttons.
2. Preparation and installation of cable tray:
(1) Cable tray and accessories should be correctly stored and kept, should not cause deformation and damage, and there should be product qualification certificates.
(2), the cable bridge should be firmly installed, horizontal and vertical, the vertical deviation should not be greater than 2/1000 of its length, the horizontal error should not be greater than 2/1000 of the width.
(3) The non-standard parts of the cable bridge made on site and the welding place must be coated with anti-corrosion primer, and the finish paint should be uniform and complete with the same color difference.
3. Cable laying:
Procedure: Material 1 Transportation and storage -- cable pipe laying and cable bridge installation -- insulation resistance test before cable installation -- cable laying.
(1) Before laying the cable, the completeness of the bridge and the integrity of the paint should be checked. The type, voltage and specification of the cable should meet the design, and there should be a product certificate.
(2) When laying the cable, spare length should be left between the terminal and the cable bridge or cable trench.
(3) When the cable is laid vertically on the bridge, the head and end of the power cable and both ends of the turning and joint should be fixed.
(4) The bending radius of plastic insulated cable should not be less than 10 times the outer diameter of the cable.
(5) When laying the cable, the cable should be drawn from the upper end of the disk, avoid the cable on the support and the ground friction drag, the cable surface shall not have mechanical damage.
(6) Cable laying should not be crossed, cables should be arranged neatly, cable terminal, cable connection, cable hole should be installed at both ends of the sign, the sign should indicate the line number (when the design has no number, it should indicate the model, specification and starting and ending place), the brand writing should be clear, not easy to fall off. Sign specifications should be unified, should be anticorrosive, hanging firmly.
(7) When the cable enters the cable trench, building, tray (cabinet) and enters the pipe, the inlet and outlet should be closed, and the pipe mouth should be sealed.
(8) The cable terminal and cable connector should be checked before production to ensure that the phase is correct and the insulating materials used should meet the requirements.
4. Wiring project:
Procedure: Piping - Threading the pipe
1) All the pipelines in this project are dark distribution. Metal pipes shall be used for wiring the lines that are dark applied in the ceiling of decoration combustible materials, open applied in wet places or buried in the ground, and PVC wire pipes can be used for the lines that are open or dark applied in dry places. For AC lines through metal pipes, different circuits should not be laid in the same pipe, and the same circuit should not be laid separately. The spacing between fixed points of metal pipes when they are open, and the clear distance when they are laid and crossed on the same side as other pipes, should meet the construction specifications and design requirements.
If the pipeline line is long, it is appropriate to install a junction box. The linear 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 laying the metal pipe, the number of roots, pipe diameter and starting point should be checked, and the omissions and those that do not meet the requirements of the drawings and current construction codes should be repaired.
2) Piping should be carried out after the plastering and ground works of the building are completed. Before threading, water and debris should be removed from the pipe. There shall be no joints and kinks in the pipe, and the joints shall be connected in the junction box.
3) After the wire is penetrated into the steel pipe, the outlet of the wire should be equipped with a protective mouth to protect the wire. After the wire is penetrated into the vertical outlet of the box (box), the pipe mouth should be used as a sealing place.