Construction method for laying out bare wires for electric power
1. Manpower cast
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.
2. Mechanical traction
This is a construction method with a high degree of mechanization, which can save a lot of labor and reduce the loss of crops. It is suitable for the payout construction of overhead lines with a large area (above 185mm2) and a long payout section. The pay-off section is divided according to the tension section. First, the traction wire rope is spread out in sections by manpower, and then connected with the anti-bending connector, so that the traction wire rope runs through the entire pay-off section. Connect the wires placed on site, and one end is pulled by a motorized grinder to drag and drop the wires. Since there is no tension in the pay-off process, the traction force does not need to be large, and the specification of the traction wire rope is generally φ9.2mm. However, for mountain lines with large spans or large height differences, or those with longer pay-off sections, necessary calculations and verifications should be carried out, and the traction wire rope should be selected according to the maximum traction force. If the line segment is very long, it can be carried out in sections, and then the wires can be connected.
3. Tension pay-off
The tension pay-off adopts the construction method that the tension tower passes straight through, the straight tower tightens the line, the tension tower is balanced and hangs the line, and the tension field and the traction field are concentrated and crimped. The guide wire ropes laid out by manpower run through the pay-off section and are connected to the tension field and the traction field at both ends of the pay-off section. The small tractor set in the tension field pulls the lead wire rope connected to the other end of the guide wire rope from the traction field to the tension field while winding the guide wire rope with constant tension). Then connect the end of the wire pulling wire rope to the pay-off board connected to the wire, and the wire passes through the tensioner. Then use the main tractor of the traction yard to rewind the wire to pull the wire rope, and pull the wire to the traction yard. Because the wire has a certain tension through the tension machine, it is always in a suspended state during the pay-off process, avoiding the friction of the ground on the surface of the wire and other obstacles, thus achieving the purpose of protecting the wire. However, the tension pay-off is more complicated, the technical requirements are very high, and there are many mechanical equipments.