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.
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