The three-phase sequence of overhead lines should meet the following requirements: from the left side for load, the phase sequence of conductors is Ll, N, L2, L3, and the zero line is generally on the road side of the pole. Poles are generally erected on the north and east sides of the road.
Requirements for the Use of Access Lines
Construction requirements of the connection line: the connection line is an overhead conductor leading from the pole of the overhead line to the first supporting point of the building.
High and low voltage connections should not cross railways. Low-voltage connection should not pass through the vicinity of high-voltage lead.
The spacing of the connection line from the tower should not exceed 30 meters. Distance between lines: 10kV and below should not be less than 0.5m, 0.5kV or below should not be less than 0.3m.
Insulated conductors should be used in low voltage connection, and the cross section should be selected according to the safe current of conductors. The distance to the ground is not less than 2.5 meters.
Low-voltage connection lines across traffic streets, vertical distance should not be less than 6 meters, special location should not be less than 3.5 meters.
The distance between low voltage connection and weak current line should not be less than 0.6 meters.
Construction requirements of the entry line: The entry line is an insulated conductor connected from the first outdoor support point to the first indoor support point. Its construction requirements are as follows:
The entry point should not be less than 2.7 meters. If it is too low, the entry pole should be added.
Insulated conductors are used for the incoming wires, copper wires not less than 2.5 mm 2, aluminum wires not less than 10 mm 2, and no joints are allowed in the middle of the incoming wires.
Installation of household casing should be added when the line goes through the wall. The wall thickness of the household casing should be no less than 2.5mm for the steel pipe and no less than 2mm for the hard plastic pipe. Waterproof elbows should be made when the pipe extends out of the wall. The exposed part of the house shall not be less than 6 cm.