Jun. 07, 2022
1. Metal conduit construction requirements
(1) steel conduit shall not be connected by fusion welding; galvanized steel conduit or steel conduit with wall thickness less than or equal to 2mm, shall not be connected by fusion welding of the casing.
(2) galvanized steel conduit, bendable metal conduit and flexible metal conduit shall not be fusion welded connections.
(3) dark with the surface of the conduit buried depth and the building, the distance between the surface of the structure should not be less than 15mm. when the plastic conduit in the wall slotted buried, should be used strength grade of not less than M10 cement mortar plaster protection.
(4) the bending radius of the conduit requirements 1) the bending radius of the plain conduit should not be less than 6 times the outer diameter of the pipe, when there is only one bend between the two junction boxes, the bending radius should not be less than 4 times the outer diameter of the pipe; 2) the bending radius of the conduit buried in the concrete should not be less than 6 times the outer diameter of the pipe, when buried directly underground, the bending radius should not be less than 10 times the outer diameter of the pipe.
(5) outdoor buried steel conduit, buried depth should meet the design requirements, the wall thickness of steel conduit should be greater than 2mm; conduit mouth should not be open vertical up, conduit mouth should be set in the box, box or the end of the conduit waterproof bend; conduit mouth in the penetration of insulated wire, cable should be sealed after processing.
2. Metal conduit and protection conductor connection requirements
(1) when non-galvanized steel conduit using threaded connections, the ends of the connection should be fusion welded to protect the connection conductor; fusion welded to protect the connection conductor should be round steel, diameter should not be less than 6mm, the lap length should be 6 times the diameter of the round steel.
(2) galvanized steel conduit, bendable metal conduit and flexible metal conduit connection at both ends of the special grounding card should be used to fix the protection connection conductor; special grounding card fixed protection connection conductor should be copper-core flexible wire, cross-section should not be less than 4mm²;.
(3) metal conduit and metal ladder frame, tray connection, galvanized material at the connection end should be fixed with a special grounding card to protect the connection conductor, non-galvanized material connection should be fusion welded to protect the connection conductor.
