Factors affecting the current carrying capacity of cables

 The current carrying capacity of the wire and cable refers to the amount of current carried by the line conductor. During the use of the wire and cable, the maximum current required by the load must be less than the long-term allowable current carrying capacity of the wire in the air. So, what are the specific factors that affect the current carrying capacity of wires and cables? Guangdong Rifeng Cable Co. Ltd

1. Core area
   Under normal circumstances, the core area (cross-sectional area of ​​the wire) is proportional to the current-carrying capacity, that is, the larger the core area, the greater the current-carrying capacity.
2. Conductor material
   The current carrying capacity of different materials under the same conditions: silver>copper>aluminum. If copper wire is used to replace aluminum wire, the current carrying capacity can be increased by 20%-30% under the same specifications.
3. Insulation material
   The temperature resistance of commonly used insulating materials is polyvinyl chloride: 70°C, cross-linked polyethylene: 90°C, and polyolefin material: 150°C. The use of insulating materials with good high temperature resistance and thermal conductivity can increase the current carrying capacity of the cable.
4. Contact resistance
   The smaller the resistance coefficient of the cable, the larger the allowable current-carrying capacity. Therefore, soldering, soldering, and crimping can be considered when bonding wire ends to reduce contact resistance.
5. Cable spacing
   When multiple wires are laid in parallel, the proximity effect and skin effect will be formed, so that the electric charge is concentrated in the part of the wire cross section and the allowable current carrying capacity of the wire is reduced. In addition, applying multiple strips will cause heat accumulation, which will also reduce the current-carrying capacity.
6. Ambient temperature
   The greater the thermal resistance around the cable, the worse the heat dissipation and the smaller the current carrying capacity.