Boundary voltage between high-voltage cables and low-voltage cables

The boundary voltage is 35kV:
Low voltage cable: ≤ 1kV, used for terminal distribution (such as household and commercial buildings)
High voltage cable: ≥ 35kV, used for long-distance transmission and high-voltage scenarios such as substations.
Boundary criteria and basis
• Boundary voltage: According to the current classification standards in China, the voltage level of low-voltage cables is 0.6/1kV and below, while the voltage level of high-voltage cables is usually 35kV and above
• Intermediate classification: The voltage range of medium voltage cables is 3kV to 35kV, high-voltage cables cover 35kV to 110kV, and ultra-high voltage cables cover 110kV to 750kV. The starting point of high-voltage cables is set at 110kV, which may be due to a broad understanding of the term "high voltage" (such as distinguishing transmission and distribution systems). Cables with voltage levels of 35kV and above have been clearly classified as high-voltage cables, while 110kV and above belong to a higher classification (high voltage or ultra-high voltage).
Practical application boundary: In the power system, equipment with voltage levels of 1000V and above is defined as high-voltage electrical equipment (according to the 2009 Power Regulations), but cable classification needs to be further subdivided based on specific voltage ranges.