When choosing a power cable, several factors need to be considered to ensure the suitability, safety and economy of the cable. Here are some key selection elements:
1. cable application
First of all, we must clarify the purpose of the cable. Power cables are mainly used for transmission and distribution of electrical energy, and are suitable for various occasions that require electrical energy supply. In the selection, to determine the required cable type, such as low-voltage power cables, high-voltage power cables, etc., to meet different voltage levels and current needs.
2. laying conditions
The laying condition of the cable is also an important factor in the selection. In different environments, cable laying methods and protection requirements are also different. For example:
In areas with more mechanical damage and erosion factors, armored cables should be selected, and their metal sheaths can effectively resist external damage.
In the case of high drop and vertical laying, plastic insulated cable is more suitable because of its simple manufacture, light weight, convenient installation and maintenance.
In the presence of corrosive gases or objects in the environment, anti-corrosion cables should be selected to ensure long-term stable operation of the cable.
3. Security
Safety is an important part of power cable selection. Different occasions have different safety requirements for cables. For example:
Low-smoke halogen-free cable does not contain halogen, will not release toxic halogen acid gas when burning, suitable for hospitals and other places with strict environmental hygiene requirements.
Flame-retardant cables can limit the spread of flame in the event of a fire, and are suitable for use in places where personnel are dense and require high protection such as power stations, large mining industries, and oil fields.
Fire-resistant cables can maintain normal operation even after a fire for a period of time, so they have irreplaceable advantages in highly safety-demanding environments such as nuclear power plants, subways, and tunnels.
4., cable specifications
The selection of cable specifications needs to consider several working attributes such as thermal response, voltage loss, economic current density and mechanical strength. To be specific:
Due to its large load current, the low voltage power line should first consider the heating condition when selecting the cable.
The low voltage lighting line has a higher requirement on the voltage level, and the voltage loss should be given priority in the selection.
When choosing cable specifications, you should also pay attention to the conductor cross-sectional area of the cable (that is, the square number of the wire), which determines the current carrying capacity and voltage loss of the cable. In general, the larger the cross-sectional area of the conductor, the greater the current carrying capacity of the cable, but the voltage loss will also increase accordingly. Therefore, the choice should be balanced according to the specific needs.
