Using overhead cables can significantly reduce various short-circuit faults (especially flashover faults common in bare overhead conductors), with a failure rate 4-6 times lower than that of bare overhead conductors.
Domestically produced overhead cables underwent trial operation in Shanghai in 1988. The test cable ran along the densely tree-lined Huaihai Road, withstanding the typhoon season and high summer temperatures in Shanghai. It performed well, and its power supply failure rate was significantly lower than that of the original bare overhead conductors. Overhead cables do not produce water treeing during use, and the insulation quality showed no significant decline after many years of operation.
Using overhead cables greatly reduces electric shock accidents. Tests and calculations show that even if a hand touches the surface of the live cable insulation, the induced current is less than 0.1mA (10kV) and 0.2mA (35kV), significantly lower than the 50-100mA lethal standard stipulated in national electrical safety regulations. It is evident that when overhead cables are energized, if a human or other animal accidentally touches the cable insulation surface, it will not cause harm to humans or animals as long as the cable is not punctured.
