Why is the live wire live The neutral wire is not electrified

The reason why the neutral wire is not charged is because it is directly connected to the earth, and the voltage after the two connections is zero, so it is not electrified.

If a number of neutral wires are electrified, it means that there is a problem with the connection with the ground, it may be that the neutral line is broken, or it may be that the two are not in good contact, which will cause the neutral line to be electrified, if it is not, then there is a fault on the line.

Because the live wire is connected to the power supply, and the neutral wire is not connected to the power supply, the live wire is electrified.

The neutral line has no electricity in the case of closing, in a path.

There is no distinction between the line of fire and the line of zero. Because he is a pathway, and at any point in this pathway, there is electricity.

If it is the neutral wire, the live wire is live and the electrical appliances can be used normally, it means that the neutral wire and the ground wire are not connected together, or the connection point of the neutral wire and the ground wire is burned out in the case of a fault.

At the same time, there is a phase line grounding, at this time, the voltage with a multimeter should be 220V between the two wires, the original zero line to the ground 220V, the live wire to the ground 380V. If the appliance does not work, then the neutral line is broken at the incoming end.

Extended information: The alternating voltage of the mains line is 220 volts (abbreviated as volts, the symbol is V), one of which is connected to the earth, which is called the "zero line", and the other wire is called the live wire. In electrical engineering, it is often referred to as the neutral line of fire or the one-zero-one fire.

The circuit switch for entering the home is generally to cut off the live wire and install a leakage protector to prevent personal electric shock accidents.

Under normal circumstances, the ground wire will not leak, and the common ones are: two-hole, three-hole socket. In general, in the two holes, the left hole is connected to the neutral line, and the right hole is connected to the live wire. In the three-hole socket, the upper hole is connected to the ground wire, the left hole is the neutral wire, and the right hole is the live wire.

<> neutral line is n, which is connected to the center line point of the transformer, and whether the measurement line is "electrified" is based on n, so you measure the neutral line is "out of power".

The zero line has no electricity, and the live wire has electricity for the earth; The neutral line is the neutral wire of the three phases of the generator or transformer, and 220V is one of the neutral wires and the three phases; In a three-phase load circuit, the neutral wire is current-free, and when the three-phase load is unbalanced, the neutral wire will generate current. In the process of power transmission, the three-phase overhead line or underground cable of power transmission is transmitted, and the neutral wire is connected to the neutral wire buried in the generator and the transmission transformer buried in the earth. The neutral line of 220V is drawn from the neutral wire of the transformer, so the neutral line is electrified (also because the neutral line is co-ground).

1. The zero line of the generator is not grounded, but its core and shell need to be grounded in the design. Therefore, there is a voltage between the live wire and the ground, but because the neutral wire is not grounded, the live wire only has a capacitive current to the shell, and there will be no large electricity; If the three-phase live wire of the generator A and the three-phase live wire of the generator B are connected according to the three-phase phase sequence (a, b c), that is, the two generators run in parallel and can supply power to the load at the same time, and all the generators connected to the grid are connected to the grid in this way. If it is not connected according to the phase sequence, a large short-circuit current will occur at the moment of closing, which will burn out the generator; 3 If the two generators are connected to the grid in accordance with the above 2 requirements, their live wires can be used interchangeably, and theoretically the neutral line can also be used interchangeably.

However, starting from safe operation, it should be recommended that each generator set its own zero line;

4. If the load section of the generator is connected to a long line, it is equivalent to the generator being unloaded. However, because the line is infinitely long, which means that the line capacitance is infinite, the voltage at the end of the line will increase due to the capacitance effect, and the generator side has no effect, as long as the excitation current is used to control the generator outlet voltage;

Questions. How to deal with the generator neutral line voltage is too low.

How to deal with the generator neutral line voltage is too low.

Reply.

Uh-huh, okay, sorry to wait.

1. The speed of the prime mover is too low. Treatment: Adjust the prime mover speed to the rated value.

2. The resistance of the excitation circuit is too large. Treatment: Reduce the resistance of the magnetic field rheostat to increase the excitation current.

For semiconductor excitation generators, check whether the additional winding joints are broken or connected incorrectly. 3. The exciter brush is not in the neutral position, or the spring pressure is too small.

Adjust the brushes to the correct position, replace the brushes, and adjust the spring pressure. 4. Some rectifier diodes are broken down. Processing:

Inspect and replace the broken diode. 5. There is a short circuit or grounding fault in the stator winding or excitation winding. Processing:

Check for faults and clear them. 6. The contact surface of the brush is too small, the pressure is insufficient, and the contact is poor. Processing:

If it is caused by the surface of the commutator, the surface of the commutator can be polished with an abrasive cloth at low speed, or the spring pressure can be adjusted.

What you say about electricity and no electricity is relative, for a live wire, as long as there is no voltage difference between you and it, for you, it has no electricity, and there is a voltage difference between you and it will have electricity. The "zero line" is connected to the earth in the power supply station, you stand on the earth, there is no voltage difference between you and the zero line, so there is no electricity, (and the live wire is not connected to the earth in the power supply station, there is a voltage difference between you), just like the ultra-high voltage power grid of hundreds of thousands of volts, the workers operate in the metal basket with the same potential as them, and it is also the same as the reason that you are similar to the same potential of the zero line, it is safe.

There is a voltage of 220V between the live wire and the earth. There is also a voltage of 220 between the live wire and the neutral wire. The voltage between the ground wire and the neutral wire is 0V.

At the transformer, the neutral line is the neutral wire in the three-phase electricity. The neutral wire on the generator or transformer is grounded. As a result, there is no electricity at the zero line.

Because the zero line in the transformer has been able to lift the slag by the grounding is only quiet, you stand on the ground with a voltage tester to measure the voltage without display, because the zero line and the earth are the same mountain bureau potential, so no current passes.

Under normal circumstances, the neutral line is not electrified.

There are three situations when the neutral wire has electricity and the live wire does not have power:

One is because the neutral line is reversed with the live wire;

The second is the aging of the neutral line joint, resulting in poor contact, and the electrical appliance is connected to the socket, which will form a loop;

The third is that there is a live wire grounding in the three-phase four-wire system, which leads to the neutral point offset, and at this time, there will be a situation where the neutral line has electricity and the live wire has no power in the test with a pen, which needs to be repaired in time.

The switch of a single-phase appliance (e.g. a lamp) is incorrectly disconnected from the neutral line.

When the switch is turned off, the live wire enters the switch through the bulb and will still be charged at the switch point.

When the switch turns on the bulb to glow, the switch is connected to the neutral line, and the whole switch is not charged.

The zero line of the electrical appliance is live, indicating that the zero line has been disconnected from the common zero line.

There is electricity before the live wire, and there is no electricity when the fire is fired, because the entrance of the live wire has been broken or entered through high resistance.

The multimeter measures that the voltage of this 'live wire' to the ground is less than 30 volts, indicating that the live wire has been disconnected, and other charged bodies below 30 volts are induced by [distributed capacitive induction].

The multimeter measures that the 'live wire' is higher than 60 volts, which means that the live wire has passed through other electrical appliances, and it is no longer a real power supply live wire.

What is the reason why the live line is not energized and the neutral line is electrified? The reason why the live line and the neutral line are live is that the neutral line in the line is disconnected, and the circuit cannot form a loop, resulting in the electrical appliances not working normally, and the zero line is a bit of a phenomenon. As soon as an open circuit is found and connected, it will return to normal.

The reason why the zero line of the circuit is not electric is that the zero line in the line is broken, and the circuit cannot form a loop, resulting in the electrical appliances not working normally, forming the phenomenon of zero line with points, as long as the open circuit is found, it will return to normal.

The electricity network connection is not standardized, there are abnormal connections, and some parts are powered off, but other parts are still in the state of power supply.

Indicate that the line is electrified, that is, the line you measure is in use, for example, if the light is on in your lighting line, then the electric pen fire line and the neutral line will be lit, or your TV, washing machine, etc. are in use, then the electric pen will also be bright. If you turn off all the lights and electrical appliances in your home, and no electrical appliances are in use, then you use a voltage tester to measure, the zero line will not be lit, only the live wire will be lit This phenomenon has two situations: 1. It is in a one-way circuit, that is, in a circuit, if the zero line is on, it means that the zero line is open; 2. In the three-phase circuit, this situation will also occur when the load of each phase is unbalanced or the internal turn and phase short circuit and the neutral point displacement of the three-phase alternating current.

3. The pressure drop is generated by the heating of the zero line. Extended information: causes and solutions of electrification 1, the zero line is not well grounded, if it is well grounded, the current will flow into the ground, with a pen will not be detected.

If the neutral line is detected to be live with an electric pen, either the neutral line is broken, or the contact is not good. But this is actually the result, not the cause of the zero line being electrified; 2. Reason: Under normal circumstances, there should be no electricity on the neutral line.

Therefore, once there is electricity, it must be a sign of failure; The simplest is electromagnetic induction, and at this time, the zero line is not well grounded and fails to form a loop; Secondly, the electrical equipment leaks or the phase wire touches the shell, but the current is not large, so it has not tripped; The neutral line is electrified, and the neutral wire is definitely not well grounded; After the problem is solved, go to the cause of the device. In the three-phase four-wire power supply system, if the neutral line is not well grounded or the ground terminal is broken, the consequence is that the potential of the neutral line is not equal to 0 when the three-phase load is unbalanced, that is to say, the neutral point is offset. The specific zero line potential is related to the three-phase load unbalance, the more unbalanced, the greater the neutral point offset, and the higher the potential of the neutral line.

After the neutral potential is offset, the phase voltage of the three phases is generally not 220V. Some phases may exceed 220V, while others may be below 220V. If the neutral point offset is too large, the phase voltage of the three phases may be burned out, and the phase voltage of the three phases may not work.

When the potential of the neutral wire is raised, the ground touch wire will cause a risk of electric shock when it reaches a certain value.