What is three phase voltage and what is single phase voltage?

Three-phase voltage is the voltage between phases, there are many voltage standards in various countries around the world, three-phase voltage 220V is one, three-phase 380V is another, and there are other voltages; In addition, the frequencies are also available in 50Hz and 60Hz. At present, China's three-phase voltage standard is 380V, and the frequency between each phase is the same, and the frequency is 50Hz. Due to the use of star connection for residential electricity access, if China says three-phase 380V, it refers to the line voltage, and the phase voltage is 220V; If we say three-phase 220V, it refers to the linear voltage, and its phase voltage is 127V.

Taiwan and other places are such power sources. Japan is a special case in the world, the east and west of Japan are different power grids, the phase voltage is 120V 60Hz and 220V 50Hz respectively, and at the same time access to the triangular connection used by residential electricity, so in Japan said that the line voltage and phase voltage are equivalent.

The voltage between the phase and the neutral wire is called the single-phase voltage, and the voltage is 220V.

The 3-way voltage is composed of 3 and 220V voltages, one of which is 220V with the wire, and the other is 380, and the 3-way voltage is a loop with each other, so there is no neutral line.

U, V, W, the line voltage between phases is 380V, which is three-phase electricity (generally marked as L1L2L3 in the drawing).

Two-phase electricity, only live wire and neutral wire, the voltage is 220V (generally marked as L, N in the drawing).

And that's just in China.

The three-phase voltage is higher than the voltage of 360V! 、

The electric phase voltage is the voltage of 360V-280V.

There should be no limit on the number of volts in the three-phase voltage, some people think that 380V is the three-phase voltage, 220V is the single-phase voltage, you can simply think of it at the beginning, but in practice, you can often encounter the three-phase voltage of 220V. If you want to distinguish, you can see that if the circuit has three live wires, which are generally marked as L1L2L3 in the drawing, it can be regarded as three-phase electricity. The two-phase electricity, only the live wire and the neutral line, with the electric tester to measure only one of the electricity.

Three-phase voltage. A generator that can produce an electric potential of equal amplitude, equal frequency, and 120° phase difference is called a three-phase generator; Using a three-phase generator as a power source, it is called a three-phase power supply; A circuit that is powered by a three-phase power supply is called a three-phase circuit. U, V, and W are called three phases, and the voltage between the phases is the line voltage, and the voltage is 380V.

The phase voltage between the phase and the center line is called the phase voltage, and the voltage is 220V.

The single-phase voltage is direct current.

The three-phase voltage is the voltage between the phases.

At present, China's three-phase voltage standard is 380V

The screen rate is the same between each phase.

The single-phase voltage is the voltage of each phase line to the neutral wire.

The neutral wire is the ground wire as the saying goes.

The ground wire is derived from a point other than the 120-degree angle of the transformer terminal.

In engineering construction, single-phase voltage refers to:

The voltage of the operating neutral line.

Not the ground voltage.

In this case, the ground wire is used as the protection neutral line.

And the working neutral line is also the working neutral line.

Three-phase voltage: three different generators, all of which generate alternating current, and the current and voltage are all sine waves, but the value of the sine wave of the three generators is not the same at the same moment, one is a zero degree sine wave, the second is 120 degrees, the third is 240 degrees, and of course the third is 120 degrees different from the first. This difference between them is fixed, and the difference of this angle is called the phase difference, and the so-called three-phase electricity is a power supply with three phase differences.

This answer comes from Huatian Power.

The differences between three-phase 220V and single-phase 220V are as follows

1.The voltage is different.

Three-phase 220 volts, refers to the wire voltage is 220 volts. Single-phase 220 volts refers to a voltage of 220 volts between wires and ground.

2.The number and structure of wires are different.

The difference between three-phase 220 and single-phase 220 is that three-phase 220 uses four wires, of which three wires are live wires and one is neutral wire, and single-phase 220 is two-wire, one of which is live wire and one is neutral wire.

Single-phase 220V is the direct grounding system at the center point of the transformer, the voltage of each live wire to the ground (or neutral line) is 220V, and the voltage between every two live wires is 380V. Three-phase 220V is the center point ungrounded system, each live wire to the ground voltage is 127V, and every two live wires are 220V.

3.Three-phase power supply is generally used for industrial power supply, two-phase power and single-phase AC power - general use and household power supply. There are many uses of three-phase alternating current, and most of the alternating current electrical equipment in the industry, such as motors, use three-phase alternating current, which is often referred to as the three-phase four-wire system.

In daily life, single-phase power supply, also known as lighting electricity, is mostly used.

The characteristics are different: Three-phase electricity is three phase wires. We often call the phase wire the live wire, and the neutral wire the neutral line.

The so-called single-phase electricity is a one-phase live wire (of course, there is also a one-phase neutral wire), and the voltage between the live wire and the neutral wire is 220V.

The higher the voltage, the greater the risk of electric shock. Therefore, for home circuits with low power requirements, 220V single-phase electricity with a lower voltage is used. Single-phase electricity is in three-phase electricity, and a phase wire is taken, so the voltage is 220V.

Precautions for three-phase electricity

According to the regulations, the neutral wire of the 380 volt (three-phase) civil power supply should not be grounded at the entrance end (grounded at the transformer end, this grounding is to take into account that the potential higher than the power supply voltage can not be caused by the suspension potential, and the grounding of the user end and the grounding of the transformer end have a certain resistance in the ground), and the power supply mode is a live wire and a neutral wire (neutral lead wire) to form a loop, and there is also a grounding wire in the single-phase three-core power jack.

This is taking into account the realization of the function of the leakage protector, (the working principle of the leakage protector is: if the human body touches the wire end of the power supply, that is, the live wire, or the internal leakage of electrical equipment, then the current flows from the live wire through the human body or the shell of the electrical equipment into the earth, and does not flow through the zero line, the current of the live wire and the zero line will not be equal, and the leakage protector immediately trips to protect the safety of people and electrical appliances after detecting this part of the current difference, and the difference current is generally selected in tens of milliamperes).

The differences are as follows:

First, the voltage is different

1. Single-phase electricity: 220 volts.

2. Three-phase electricity: between the phases voltage of 380V.

Second, the nature is different

1. Single-phase electricity: a phase wire (commonly known as live wire) and a neutral wire composed of electric energy transmission form, if necessary, there will be a third wire (ground wire) to prevent electric shock.

2. Three-phase electricity: a power supply composed of three alternating currents with the same frequency, equal amplitude and 120° difference in phase.

Safety knowledge: The voltage of the three-phase wire of the low-voltage power supply line in China is 380V, and the phase voltage to the ground (neutral wire, also known as the neutral line) is 220V.

When using phase voltage power supply, if there is a lack of neutral line, the grounding wire of the equipment can be used as the neutral line, but the grounding must be good (in general, in addition to the three-phase four-wire power supply, the equipment is equipped with a grounding wire). Regardless of whether it is an N line or a PE line, repeated grounding is used on the user side to improve reliability.

The low-voltage power supply for residents is a 3-phase 5-wire system, and the 5-wire is named: A: A phase, live wire (potential to the ground 380V).

B: B phase, live wire (potential to ground 380V) C: C phase, live wire (potential to ground 380V) N: neutral wire, neutral wire (potential to ground is basically 0V) PE: ground wire, ground wire (potential to ground 0V).

For the above lines, the voltage between any two of A, B, and C is AC 380V, that is, 380V between A-B, B-C, and C-A; For the above lines, the voltage between any one of A, B, and C and N is 220V, that is, 220V between A-N, B-N, and C-N.

What is the difference between three-phase 220v and single-phase 220v? Hello dear, there is a difference between three-phase 220 and single-phase 220. Three-phase 220 refers to a three-phase circuit with a line voltage of 220V, and the phase voltage of each live wire is 110V, that is, a three-phase circuit with 220V 110V, and single-phase 220 refers to a single-phase circuit with a phase voltage of 220V, which is a phase circuit in the 380V 220V three-phase four-wire.

Three-phase 220 circuit is generally used in some imported equipment, such as Japan, Taiwan's equipment motor, is the use of three-phase 220V electricity, single-phase 220 is the low-voltage circuit commonly used in China, such as civil lighting electricity. Hope it helps. If my answer is helpful to you, please give a thumbs up (in the lower left corner), I look forward to your like, your efforts are very important to me, and your support is also the motivation for my progress.

Finally, I wish you good health and a happy mood!

Relationship between line voltage, phase voltage, line current, phase current:

The three-phase load is connected according to the star shape, the line voltage = the root number 3-phase voltage, and the line current = phase current.

The three-phase load is connected in a triangle, the line voltage = phase voltage, and the line current = 3 times the phase current of the root number.

Just keep in mind that when the triangle is connected, the line voltage = phase voltage, draw a simple diagram, you can clearly see that the power line voltage is directly added to each phase load when the triangle is connected. Remember one, and the rest can be quickly deduced.

Characteristics of three-phase power supply:

Combine three alternating currents of equal size, the same frequency, and a difference of 120° in the initial phase to form a three-phase intersecting current. The actual three-phase alternating current is generated by a three-phase generator, where three identical windings are evenly distributed according to the spatial difference of 120°. In this way, the generator rotation can produce three single-phase alternating currents that meet the above conditions.

Due to the 120° difference in the initial phase, there is a time difference in the current flowing through each wire, so that there is no need for six wires for power supply, but only three windings need to be connected in a certain way inside the generator, and three or four wires are used for power supply. The alternating current emitted by each winding of the generator is called one of the phases of the three-phase alternating current, which is the single-phase alternating current we use.

Single-phase voltage refers to the voltage of only one phase in the power system, such as single-phase 220V alternating current, which is commonly used in household electricity. The three-phase voltage refers to the voltage of three phases in the power system, that is, three-phase electricity, in which the amplitude of each phase voltage is 220V, but the phase difference between them is 120 degrees. In three-phase electricity, the voltages of the three phases alternate in a specific way, so that the balance and stability of the closed limbs of the power transmission can be achieved.

The three-phase load is connected according to the star shape, the line voltage = the root number 3-phase voltage, and the line current = phase current.

The three-phase load is connected in a triangle, the line voltage = phase voltage, and the line current = 3 times the phase current of the root number.

In a triangular connection, the two points at which the phase voltage and the line voltage are measured are the same, so they must also be equal; A line current will be divided into two phase response currents (one outlet end is connected to two phase windings), so the line current will be greater than the phase current.

In the star connection, it is just the opposite, the line voltage of the first gear contains two phase voltages, so the line voltage must be greater than the phase voltage; And the phase current is the line current, that is, the two are equal.

Because the relationship between three-phase voltage and three-phase current is not a simple algebraic relationship, but a vector relationship, that is, a vector relationship, it cannot be dealt with by a simple addition and subtraction relationship, but by the addition and subtraction relationship of vectors.