The conductor wire of a single-phase generator is actually no different from the live wire and the neutral wire. However, if one end of the coil is grounded, the voltage of the conductor wire at the ground end is equal. always zero, that's why it's called the neutral wire. If the stator coil ground terminals are reversed, the live and neutral wires are reversed. The same goes for three-phase generators. In order to save material, the three ground terminals are combined to form a common neutral line, saving 2 wires.
PS: In fact, the neutral line voltage is not always zero. When the switch is closed, current flows in the neutral line. Due to the resistance of the wire itself, there is residual tension.
Why does the neutral line come out of the generator?
First of all, you need to understand the principle of the generator. Generally, the generator output is triphased. All three lines are live wires and have electricity. The three lines form a Y shape and the point of intersection is the neutral line. For a specific live wire, current flows from left to right at one moment, and from right to left at the next moment, and the three wires alternate in turns. Under ideal conditions, the voltage at the crossover point is always 0, because line A is assumed to be +100 V, line B to be +200 V, and line C to be -300 V.
If the generator is made perfectly, there will be no electricity even if wire 0 is not grounded, but in fact this is impossible for safety reasons, wire 0 is grounded earth. earth, wire 0 is connected to our body. The voltage between them is 0, so of course there will be no electricity.
Suppose a metal plate is placed on an insulating platform and the metal plate is connected to the live wire. WeWe stand on the metal plate and do not touch other objects in relation to us, the metal. The plate (live wire) is "line 0".
When we come into contact with the zero line of reality at this time, we will receive an electric shock, and the zero line of reality becomes the “line of fire”. This is what happens when a plane lands.
Where is the neutral wire of the 380V generator?
The three phase generator has four wires, three live wires and one neutral wire. This is a three-phase, four-wire wire. system. It is divided into A, B, C and N. The voltage between the three wires ABC is called phase voltage, which is 380 volts AN or BN or CN is connected to the live and neutral wires of your house, which is 220. Volts. Because it is alternating current, alternating current, the neutral line is connected to ground, and the potential difference between it and ground is 0 V. The other line is not connected to the twanders and the potential difference between it and the earth. is 220 V. This line is the live wire.
L: live wire, N: neutral wire.
1. Use color to distinguish: In the power cable, green and red represent phase A, phase B and phase C respectively (the wire under three-phase voltage represents the). neutral line, and yellow and green are two colors. Represents the ground wire.
2. Use an electric pen to distinguish: the live wire will glow when tested with an electric pen, but the neutral wire will not.
3. Use a voltmeter to distinguish: the voltage between the phase wires (that is, the live wire) is 380V, and the voltage between the phase wires (live wire) and the neutral wire (or a good grounding body) has a phase voltage of 220 V, and the voltage between the neutral line and a good grounding body earth is 0 V.
Detailed information:
Notes:
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According to the load of the electric meter, inductance coils with different transformation ratios can be selected to meet the usage requirements. For example, if an electric meter with a specification of 3x1(2)A is used with an inductor coil and the inductance coil ratio is selected as 1:50, the maximum current rating that each phase can carry is of 100 A.
In accordance with regulations, the neutral wire of the 380 V civil power supply must not be earthed at the input. If grounding is done on the transformer side, this grounding is to ensure that the potential is not higher than the supply voltage due to floating potential. There is some resistance in the ground between the user side ground and the user side ground.the user. the end of the transformer. The power supply method is one live wire and one neutral wire, that is, the neutral point conductor wire, forming a loop. There is also a ground wire connected to the single-phase, three-conductor power outlet.