Rated power of semi-rigid cables

Semi-rigid cables use copper pipes as external conductors and do not have sheathing, so they have high heat resistance, and their rated power is greatly affected by the upper limit of surface temperature.
 
·Rated power at ambient temperature 25°C, natural cooling, and upper limit of surface temperature 49°C

 
·Rated power at ambient temperature 25°C, forced air cooling, and upper limit of surface temperature 150°C

 
·Rated power calculation model
The semi-rigid cable is treated as a single heat-generating body, and all RF signal attenuation is converted into heat. The temperature at which heat transfer from the cable surface to the air and heat radiation for heat dissipation balance with heat generation inside the cable is calculated. The power at which this equilibrium temperature equals the maximum surface temperature is defined as the rated power.
·Physical properties used in the calculation
Natural convection heat transfer coefficient: 5 W/mK
Forced air cooling convection heat transfer coefficient: 25 W/mK
Copper surface emissivity: 0.1
Forced air cooling air velocity: 0.5 m/s
Copper-clad steel wire softening temperature: 150°C
These values are general representative values and may vary significantly depending on the actual installation environment of the cable. When selecting a cable, please allow for sufficient margin.