For the steel conduit laid buriedly, the burial depth should meet the design requirements, and the wall thickness of the steel conduit should be greater than 2 mm; The nozzle of the catheter should not be open vertically upward, and the nozzle of the catheter should be provided with a waterproof bend in the box, box or at the end of the conduit;
The conduit leading from the box-type substation or floor-standing distribution box to the building, and the conduit nozzle on one side of the building should be located in the building. The nozzle of the conduit should be sealed after penetrating the insulated wire and cable.
The maximum outer diameter of the wire conduit laid in the reinforced concrete cast-in-situ floor slab should not be greater than one-third of the thickness of the slab. When the wire conduit is laid in the floor and wall, the thickness of the outer sheath between it and the floor and wall surface should not be less than 15 mm.
When there is no sealing plate at the bottom of the box, the nozzle should be higher than the cabinet, and the base surface of the table, box and tray should be 50 to 80 mm.
When the conduit passes through the outer wall, a waterproof casing should be installed, and the waterproof treatment should be done. A compensation device should be provided where the steel conduit or rigid plastic conduit crosses the deformation joint of the building.
In addition to the inner wall of the steel conduit buried in the concrete should be treated with anti-corrosion, and the outer wall can not be treated with anti-corrosion, the inner and outer walls of the steel conduit laid in other places should be treated with anti-corrosion.
When the conduit is laid in parallel with the hot water pipe and steam pipe, it should be laid under the hot water pipe and steam pipe, and the minimum distance between the laying under the hot water pipe should not be less than 200 mm, and the minimum distance under the steam pipe should not be less than 500 mm;
When there is difficulty, it can be laid on it, and the minimum distance of parallel laying on the hot water pipeline should not be less than 300 mm, and the minimum distance of parallel laying on the steam pipeline should not be less than 1000 mm. The cross laying with hot water and steam pipelines should not be less than the net distance parallel to it; For hot water pipes and steam pipes with thermal insulation measures, the minimum distance should not be less than 200 mm.
The distance between the conduit (or wiring duct box) and other pipelines that do not contain flammable and flammable and explosive gases shall not be less than 100 mm in parallel or cross-laying; It should not be laid in parallel with flammable and flammable and explosive gases, and the cross laying place should not be less than 100 mm; When the specified distance is not reached, reliable and effective isolation and protection measures should be taken.
When the conduit crosses the airtight or protective airtight partition wall, the embedded casing should be arranged, the production and installation of the embedded casing should meet the design requirements, the length of the casing extending out of the wall at both ends should be 30 to 50 mm, and the conduit should be provided with a wire box on both sides of the closed wall casing, and should be blocked.
When the conduit is laid with a length greater than 40 meters, no bending, a length greater than 30m, 1 bend, a length greater than 20 meters, 2 bends or a length greater than 10 meters, and 3 bends, a junction box or a wire box should be added in the middle, and the position of the box should be convenient for threading.