What are cable power supply and cable size of NE80E device?
According to the whole technical demands of YD/T 1051-2000 communication site power system, the lowest input voltage of communication device is -40V. The voltage drop from power system to the cable of communication device is 3.2V.
For communication device with the lowest voltage -40V, the voltage from storage battery to the device is 3.2V. V1+V2+V3+V4+V5=3.2V. It requires V1/0.5V, V2/0.4V, V3/1.2V and V4/0.5V. According to the computation of voltage drop 3.2V, the voltage drop V5 from PDF to communication device is 0.6V.
The lowest input voltage of NE80E&NE5000E device is -38V. The roundtrip voltage drop from PDF to NE80&NE5000 device △U＝V5+ (40-38) V＝0.6+2V＝2.6V.
For NE5000E, the maximum input current is 132A and the maximum input cable cross-sectional area is 50 �, △U＝V5+(40-38)＝2.6V. The remotest transmission distance is 50 �.
50＝132×L/57×2.6 L56m is roundtrip distance. NE5000E chooses 50 � cable and power distribution is 28m.