Why do you want to separate the power cable from the communication cable?
Computer, table lamp power line current is relatively small, the magnetic field is not very strong, moreover, the network cable is double stranded wire, has the antijamming ability, this kind of situation may neglect the power line interference, does not divide separately does not matter.Many other examples, but the basic principle is: if the signal transmitted by the communication cable cable itself is relatively weak, poor anti-interference ability, to avoid the power line, not too close, such as microphone cable, satellite antenna cable, which belongs to the weak signal, power line can not be close to the strong current;But like closed-circuit television, cable, telephone lines, these are strong signals. In principle, it's important to avoid the power line, even if you don't avoid it;Not all communications cables have to be separated from the power line, and there are special cases, such as fiber, which are not subject to interference from electromagnetic signals.
For example, in the stage when the line, audio and video signal line to keep away from the power cable, not only can not be long distance close to, or even cross, are not allowed. Family decoration wiring, closed-circuit television, network and other lines can go on line, but not with the power line to walk the same path, to prevent interference, especially the supply current of high-power electrical appliances such as refrigerators, air conditioning and other equipment, strong magnetic field, should avoid communication cable.
In special cases, when the power and communication cables have to take a path, the communication cable should take shielding measures to block interference.
Because the power cable transmission is alternating current, the current is relatively large, will produce a relatively strong magnetic field, wiring, if the communication cable and power cable along with the line, will affect the communication cable.
