Low-voltage cables are conductors used to transmit power or signal currents. They are typically made of copper or aluminum and are covered with an insulating layer and a protective sheath. Low-voltage cables typically operate at voltages below 1 kV, with common voltage levels including 1 kV, 3 kV, 6 kV, and 10 kV. In low-voltage power distribution systems, cable selection depends primarily on factors such as the cable line layout, operating conditions, power supply distance, and load size.
High-voltage and low-voltage cables can be distinguished based on the following factors:
Voltage level: According to my country's voltage classification, low-voltage cables have voltage levels of 0.6/1 kV and below, medium-voltage cables have voltage levels of 1 to 35 kV, high-voltage cables have voltage levels of 110 to 220 kV, and ultra-high-voltage cables have voltage levels of 330 to 750 kV.
Insulation Materials: Low-voltage cables generally use materials such as polyvinyl chloride and polyethylene; medium-voltage cables use materials such as polyethylene and cross-linked polyethylene; high-voltage cables use materials such as cross-linked polyethylene and polytetrafluoroethylene; and ultra-high-voltage cables use materials such as synthetic rubber and silicone rubber.
Current Capacity: The current-carrying capacity of a cable can be determined by its rated current. Generally, the rated current of low-voltage cables ranges from tens to hundreds of amperes; the rated current of medium-voltage cables ranges from hundreds to thousands of amperes; the rated current of high-voltage cables ranges from thousands to tens of thousands of amperes; and the rated current of ultra-high-voltage cables exceeds tens of thousands of amperes.
Application: Depending on the application, cables with different voltage levels and current-carrying capacities can be selected. For example, low-voltage cables can be used for household electricity, while high-voltage or ultra-high-voltage cables can be used for power transmission.
In summary, the distinction between high-voltage and low-voltage cables is not simply based on voltage level; factors such as the cable's insulation material, current capacity, and application also need to be considered.
