γ indicates the conductivity. If copper conductors are used, the value is 57 m/Ω.mm^{2}; If 15% copper-clad aluminum conductors are used, the value is 36.557 m/Ω.mm^{2}.
ΔU indicates the calculated voltage drop of a loop. If the voltage is –38.4 V, ΔU is 2.6 V. If the voltage is –40 V, ΔU is 1 V.
I indicates the current in the conductor. I = Power/Voltage (40 V)
: Common power cable diameters are 16 mm^{2}, 25 mm^{2}, and 35 mm^{2}.
In case of 63 A power supply:
If the required power cable length is shorter than 20 m, use a power cable with a diameter of 16 mm^{2}.
If the required power cable length is between 20 m and 35 m, use a power cable with a diameter of 25 mm^{2}.
If the required power cable length is between 35 m and 50 m, use a power cable with a diameter of 35 mm^{2}.
In case of 125 A power supply：
the power cable diameter can only be 35 mm^{2} and the power cable length cannot exceed 25 m.
In case of 125 A power supply, the power cable diameter can only be 35 mm^{2} and the power cable length cannot exceed 25 m.
Fiber type
Fiber length (km)
Total fiber loss:0.00dB
: Total fiber loss = Reference fiber loss x Fiber length
: For transport equipment, the heat consumption and power consumption are similar and therefore can be considered the same. Heat consumption is expressed in BTU/h and power consumption is expressed in W. The equation for unit conversion is as follows: 1 BTU/h = 0.2931 W