Overhead bare conductor cable laying claims
1. If overhead bare conductor cables are arranged vertically, the distance between lines to be bigger than the horizontal arrangement, because the wire swinging up and down swing is larger than the horizontal. Such as the prescribed distance between 6KV overhead bare conductor arranged vertically is 1m, it is 0.7m horizontally.
2. On the same poles, set up both copper bare conductor cable and aluminum bare conductor cable, then the copper bare conductor cable should be erected on top. Because the thermal expansion coefficient of aluminum bare conductor is larger than copper, the vertical distance can be maintained between copper bare conductor and aluminum bare conductor when copper bare conductor cable on the top.
3. The minimum cross-sectional of overhead bare conductor cable, copper bare conductor is 6mm2, aluminum bare conductor is 16mm2. The requirement is due to considering the mechanical strength of bare conductor.
4. Bare conductor cables used in the same section must match “3 Same”, that is the same material, the same type and the same size. Neutral line cross section allows 50% smaller than phase line, but the material and the type should be corresponding to the same phase.
5. It had better to use concrete poles, because of its high mechanical strength, good corrosion resistance, and it’s cheap. Cross arm should use angle iron cross arm, because the angle iron cross arm with a durable, high strength and easy installation features.
6. When installing overhead bare conductor cable, zero line should be erected below the phase line. Due to the zero line cross-sectional area is generally smaller than the phase line, easily disconnected due to wind and other factors, it will not come into contact with the phase line, that is, the zero line is not in danger of high voltage.
7. Overhead bare conductor cable is better to use multiple strands, do not use single strand. Due to mechanical strength of multiple strands is good.
8. Overhead bare conductor cable can’t be connected by welding method, for bare conductor will be annealed under heating welding so that the mechanical strength will decline.