This construction method is suitable for overhead lines with small conductor cross-sectional area and not too long pay-off section (the pay-off section is divided according to the tension section). When laying out the line, the manpower is used to directly drag the line on the ground, without the need for traction equipment and a large number of traction wire ropes, and the method is simple. The disadvantage is that it requires a lot of labor and will damage a large area of crops. The arrangement of manpower deployment for the labor force is: the average load per person is 300N on the flat ground, and 200N on the mountain. According to the length of the guide wire, the ground wire or the length of the tensile section, several wires can be dragged and dropped at the same time at the beginning; in the later stage, due to the increase in length and weight, the first part can be gradually suspended, and the combined labor force can be dragged and dropped successively.
The high-altitude tightening method is mainly used in the tightening construction of distribution lines with small conductor cross-sectional area and low tightening tension. It has the advantages of simple construction method, small operation site and less construction equipment. However, most of the processes must be completed at high altitudes, which increases the workload of high-altitude operations. When tightening the line, the remaining line should be tightened first. Usually, it is directly operated on the ground by manpower or traction equipment. When the overhead line in front is off the ground, you can put a tensioner at a certain distance (estimated length of the tensioning line) in front of the tension operating pole tower, use the traction equipment to pull the tensioning wire rope, and tighten the wire through the pulley at the hanging line. When the overhead line is tightened near the sag requirement, slow down the pulling speed. When the sag observer in front is notified that the required sag value has been reached, the towing is stopped immediately. When the overhead line stops beating and there is no change in the sag, it can be marked on the operating pole tower according to the hole of the hanging line. After marking, the construction personnel on the tower will install tension clamps on the guide and ground wires at high altitude, and hang the guide and ground wires on the tower. This method of operation is called the one-time tightening method because the overhead line does not need to be grounded by Panasonic. If the guide and ground wires are loosened and landed after marking at a high altitude, the ground operator will install the tension clamp according to the mark, and at the same time assemble the insulator string, tighten the wire again, and hang the wire. This method is called the secondary lifting and tightening method. . The advantage is that it reduces the amount of work at heights. It is suitable for lines with large wire cross-section and tight wire tension, especially for crimping type tension clamps, which are quite inconvenient for high-altitude construction, so most of them use this method.
Check and check the type and specification of the fittings and die for connection, which should be consistent with the nominal cross-section of the cable conductor to be connected, the type of conductor structure (compressed or not) and the hardness of the conductor.
The surface of the crimping part should be smooth, and there should be no cracks and burrs. There should be no sharp points at all edges.
The insulation of wires and cables is subject to the thermal, chemical and mechanical effects brought by the electric action, so that the insulating medium undergoes physical and chemical changes, which reduces the insulating ability of the medium. The insulation is damp, the intermediate joints or terminal heads are damped due to the sealing of the structure up and down or the installation quality is not good.
The selection of the position of each indentation should be carried out according to the marked position and regulations on the connecting pipe or terminal cylinder. The axial centerline of the partial crimping pit or the center of the opposite side of the inscribed circle in the hexagonal overall crimping. The lines should all be on the same straight line. The crimping degree shall be subject to the contact between the lower die and the lower die or the effective stroke specified by the crimping pliers. After pressing an indentation, it should stay for 10~15S. Then remove the pressure. The operation method of the press clamp should be carried out according to the procedures specified in the press clamp manual of the press clamp manufacturer.