In the Three phase and Four wirecircuit system, the neutral wire is very important.
在三相四线制供电系统中,中性线是非常重要的。
2
In other words, the circuit may be physical two - wire (or even physical one - wire) and logical four - wire, performing as a four - wirecircuit but employing fewer than four wires.
换句话说,电路可以是物理双线(甚至是物理单线)、逻辑四线,它使用较少的线实现四线电路。
3
In fact, a four - wirecircuit can be established without the use of any wires at all, as in the case with a circuit established over microwave, satellite, or infrared transmission systems.