Aerial Bundled Cable

1. High reliability of power supply

The use of overhead cables can greatly reduce various short-circuit faults (especially the common flashover faults of overhead bare wires). Compared with overhead bare wires, the failure rate is 4-6 times lower.

The domestic aerial cable was put into trial operation in Shanghai in 1988. The trial aerial cable runs along the dense boulevard of Huaihai Road. After the typhoon season in Shanghai and the high temperature in summer, it runs well, and its power supply failure rate is much lower than that of the original overhead bare conductor. Overhead cables will not produce water trees during use, and the insulation quality of the cables has not significantly decreased after years of operation.

2. Good power supply safety

The use of overhead cables greatly reduces personal injury and death accidents due to electric shock [3]. The Shanghai Electric Cable Research Institute once set up a special subject to carry out the “Research and Test on Personal Safety of Overhead Cable Insulation”. Tests and calculations show that even if the insulated surface of a live cable is touched by hand, the induced current is less than 0.1mA (10kV) and 0.2mA (35kV), which is much lower than the 50-100mA lethal standard stipulated by the national electrical safety regulations. It can be seen that when the overhead cable is energized, when the human body or other animals accidentally touch the surface of the cable insulation, as long as the cable does not penetrate, it will not cause harm to humans and animals.

3. Convenient installation and maintenance

Overhead cables can be erected on any kind of poles or towers, or along walls. Under special circumstances, they can also run through the bushes and be directly fixed on the tree poles with hardware. It can be erected on a single circuit, or multiple circuits can be erected on the same pole, without requiring a wide “electrical corridor”. In installation, it can be easily erected on the original overhead line, using the original cross arm and porcelain bottle, or a full set of matching hardware and accessories. According to the actual situation of the site, the manufacturer can make some special fittings specially or self-made, so the construction is extremely convenient. Overhead cables do not need to be inspected specifically, and they will not cause short circuit trip accidents due to tree flashover, residents littering, or accidental collision of crane booms, which greatly reduces line maintenance and repair work.

4. Reasonable economy

Although the use of overhead cables is more expensive than the use of overhead bare wires, it is cheaper than ordinary underground installation cables. Therefore, although the one-time investment is slightly higher for the use of overhead cables, the operating cost will be significantly lower than that of overhead bare wires, taking into account other factors. For example, overhead cables are used to reduce the line corridor, and even multiple lines share a tower, which reduces the cost of land acquisition, and there is no need to cut and trim trees under the line during operation, which saves cutting and pruning costs. The most important thing is to reduce line failures and their The direct or indirect loss caused by the cost. Therefore, its comprehensive cost is obviously lower, more economical and more reasonable.