What does it mean that there is a 220 volt voltage between the line of fire and the earth? Isn t the

The transformer of China's power users is mostly three-phase AC 10kV high voltage to 400V low voltage between the user's three-phase phase line (that is, the usual 380V), three-phase phase line UA, UB, UC is usually called "live wire", the neutral point zero line of the transformer has a potential difference of 220V, that is, in line with UAB =, for the safety of electrical equipment and operators, the transformer shell and the neutral point zero line are connected with the earth "nearby protective grounding wire", That is to say, there is a voltage (potential difference) of 220 volts between the fire wire and the earth, and you can know it if you measure it with the AC voltage level of the multimeter.

Because the neutral point of the generator or transformer is connected to the earth, and the earth can be regarded as an infinite common end, it constitutes one point of voltage, and the live wire and the earth do not constitute two points of voltage!

There is a voltage of 220 volts between the line of fire and the earth"? In the neutral grounding system, the neutral point is connected to the earth, and there is a voltage of 220 volts between the phase wire (live wire) and the neutral point (earth).

It's two points, the line of fire counts as one, and the earth counts as one. It is generally accepted that the potential of the earth is the same.

Three-phase wire + neutral wire + ground wire, if the phase line is 380V, the phase line to the zero line is 220V, and the phase wire to the ground wire is not known, but we are now using the zero line and the ground wire.

The live and ground wires are normal at 220 volts because on the transformer side, both the ground and neutral wires are grounded at the same end.

1. The neutral line is the line drawn from the neutral point on the secondary side of the transformer, which forms a circuit with the phase wire to supply power to the electrical equipment.

Neutral line (n): Mainly used in working circuits, the voltage generated by the neutral line is equal to the line resistance multiplied by the current of the working circuit. Due to the long-distance transmission, the voltage generated by the neutral line cannot be ignored, and it becomes unreliable as a measure to protect personal safety.

Leads out the trunk after grounding from the neutral point of the transformer).

2. Live wire refers to the wire connected to the positive pole in the DC circuit.

There are two wires in the lighting circuit, one is called the live wire, and the other is called the neutral wire. The difference between the live wire and the neutral wire is that they have different voltages to the ground: the voltage of the live wire to the ground is 220v; The voltage of the neutral line to the ground is equal to zero (which itself is connected to the earth).

So when one part of the person hits the line of fire and the other part is standing on the ground, and the voltage between these two parts of the person is equal to 220V, there is a risk of electric shock. On the contrary, even if a person uses his hand to grasp the zero line, if the person is standing on the ground, because the voltage of the zero line to the ground is equal to zero, the voltage between the various parts of the human body is equal to zero, and the person is not in danger of electric shock.

3. Differences. 1) Different colors: in the power cable, yellow, green, and red represent phase A, phase B, phase C (three-phase live wire), blue represents the neutral line, and yellow and green colors represent the grounding wire.

2) Whether it is charged or not: The neon tube will glow when tested with an electric pen for the live wire, while the neutral line will not.

3) The voltage is different: the voltage between different phase wires (i.e. live wires) is line voltage 380V, the voltage between phase wires (live wires) and neutral wires (or good grounding bodies) is phase voltage 220V, and the voltage between neutral wires and good grounding bodies is 0V.

Precautions: Most of the power sockets used are single-phase three-wire sockets or single-phase two-wire sockets. In the single-phase three-wire socket, the middle is the grounding wire, which is also used for positioning, and the other two ends are connected to the fire wire and the neutral wire respectively, and the wiring sequence is the left zero and the right fire, that is, the left side is the zero line, and the right side is the fire wire. All household appliances with metal shells use single-phase three-wire power plugs.

The three plugs are arranged in a regular triangle, and the longest and thickest copper plug on the top is the ground wire. The two below the ground wire are the fire wire (the symbol letter is"l"live wire), neutral wire (the letter of the flag is"n"neutral wire), the order is left zero right fire.

The ground wire is also zero potential, and it is normal for the live wire and ground wire to be 220 volts.

Normal, the live wire to the ground wire is 22ov to the neutral line.

Normal, indicating good grounding.

The ground wire and the live wire have a voltage of 220 due to external force and construction, and the ground wire is unreliable and the neutral wire is disconnected and reversed from the live wire.

First, caused by external forces and construction.

External forces and other reasons may cause damage to the line, resulting in a voltage of 220.

The construction technology is not in place, resulting in poor contact and heat, which causes the zero line to be disconnected, and the power supply will pass through the 220 voltage caused by the N line passing through the electrical appliances.

Second, the ground wire installation is unreliable.

When the ground wire touches the ground wire, it is equivalent to the ground wire is the live wire, and there will be 220 voltage between the neutral wire and the ground wire.

Third, the neutral wire is disconnected and reversed from the live wire.

When the neutral wire is disconnected, the potential between the live wire and the load such as bulb and neutral wire, there will be a voltage of 220 between the neutral wire and the ground wire.

There will be a voltage of 220 when the neutral wire is reversed to the live wire.

This is completely normal.

Because the live wire (phase wire) at the power supply end (transformer) is a wire drawn from the transformer coil, and the neutral wire is also a line drawn from the transformer, but in the transformer circuit of the three-phase four-wire is a central point (neutral wire) of the winding coil of the three-phase wire, then the voltage of the neutral wire and any other phase wire should be 220V (China's voltage standard) under normal conditions; Because, in the power supply system, the neutral line of the transformer is grounded, so from"phenomenon"From the perspective of electrical theory, the potential of the ground wire and the neutral wire is equal (the same), and both should be"Zero potential".Therefore, in terms of measurement, the voltage of the live wire to the neutral wire and the ground wire should be the voltage value of the one-phase wire being measured--- that is, the voltage is 220V; The reason why it is divided into neutral wire and ground wire is because the neutral wire is a line that provides a current channel for the circuit when it is working normally, and the ground wire is a line designed for the safety of electrical equipment"Abnormal current"A line of the channel is set up as a protection line together with the control equipment (such as automatic air switch, etc.), and the line is strictly speaking without any value of current passing through the line when the equipment is normal, that is, the current is zero. Therefore, in terms of measurement, these two lines are connected, but the nature of the work (function) is different.

Normal. The voltage between the phase wire (live wire) and the neutral wire, the phase wire and the ground wire of the AC mains should be 220V.

Normally, it is normal for the voltage between the live wire and the ground wire to be 220 volts.

Definitely not normal. The ground wire is also called the zero wire.