Planning and Design of 10KV-35KV Overhead Cable
1.The planning and design of overhead cable lines should be coordinated with the overall planning of the city. Such as distribution planning without area, the wire cross section should be determined according to 20 A electricity load development plan.
2.Overhaul cable line spacing should not be greater than 50 m, the length of tensile section should not be greater than 1 km. The spacing between the overhead insulated lines shall not be less than 0.4 m and the compact erecting of the insulation supports shall not be less than 0.25 m.
3.If adopt the aluminum or aluminum alloy core insulation line is used, the minimum cross sectional trunk line shall be designed to be 150 mm2
and the branch line to be 50 mm2
4.On the both sides of the contact switch, the branch rod, the tension bar joint and the branch wire point with the potential to send back power shall be provided with a power failure working earth point; when the line is in normal operation, the insulation cover shall be provided for the power failure working earth point.
5.Fuses, arrester, transformer terminals and insulated wire connection parts, should be insulated seal.
6.Insulated conductors should be equipped with switchgear in the following areas:
1) A long main line or branch line
2) Ring power supply network
3) District boundary
The connection between the equipment and the insulated wire shall be provided with a special insulation cover.