I have heard that there are 3 items of electricity and a single item of electricity, but how many it

This must first figure out the "phase", usually the "fire wire" is called the "phase" line, and the few phases we say are the few live wires. The use of a live wire is single-phase electricity, which is the most used in this household (one live wire and one neutral wire power supply, voltage 220V); The use of two live wires is two-phase electricity, such as the common AC welding machine (with 2 live wires for power supply, the voltage is 380V), with three live wires is three-phase electricity, such as the common motor (with three live wires for power supply, the voltage is also 380V).

Speaking of current, the current is more verbose

1 Single-phase: the current from the zero line to the live line, and then from the live line to the zero line, non-stop round trip, our country uses 50hz, that is, 50 round-trips per second, 2 three-phase: the direction of the three-phase current is not easy to understand, it is also a flow back and forth, but it is a mutual flow according to a certain law, this can not be expressed in words, look for electrician books to understand.

380V power generally refers to 3-phase 380V industrial electricity, and residential electricity is generally single-phase 220V

In the usual sense, the 380V power power refers to three items, and the 380V connection you said is the interline load, which is to do three balances! The reason is very simple, all three are 220V plus neutral wire (ground wire), you can receive a single-phase load.

Is there anything to keep asking.

First of all, let's understand what is single-phase electricity: single-phase electricity is commonly used lighting electricity (civil electricity), the voltage is 220V, and most household appliances use 220V voltage, such as TVs, air conditioners, washing machines, lights, etc.

Three-phase electricity: also known as industrial power electricity, commonly used are three-phase three-wire, that is, three-phase wire (live wire), three-phase four-wire system, (three three-phase, one neutral wire) phase and phase-to-phase voltage, that is, the line voltage is 380V.

The main difference between them: the single-phase electricity is 220V, which is the voltage of the phase line and the neutral line. Three-phase electricity is the phase-to-phase voltage of 380V between the three phases, and the electrical equipment is three-phase electrical appliances, such as three-phase motors, three-phase electric heating appliances, etc.

Each phase of the three-phase power supply and the neutral wire can form a single-phase electric circuit, in the civil electricity phase wire is called the live wire, the neutral wire is called the neutral line, the three-phase electrical appliances can not be used for single-phase electricity, and the single-phase electrical appliances can not be used for three-phase electricity.

The electricity emitted by the power plant has 3 "phases" and a neutral wire, so that's a total of 4 wires.

If you take one of the phases and the neutral wire, which is two wires, that's called single-phase electricity, and it's 220 volts

If you take two of these phases, it's also two wires, and it's called a two-phase electricity, and it's 380 volts

If you take three phases, it is called three-phase electricity, and at this time, you can take the neutral line or not, depending on the load requirements (this is for the factory).

Single-phase electric power refers to the form of electrical energy transmission composed of a phase wire (commonly known as a live wire) and a neutral wire, and if necessary, a third wire (ground wire) is used to prevent electric shock.

Three-phase electricity is a group of three-phase alternating current with equal amplitude, equal frequency and 120° phase difference between each other, which is generated by a three-phase generator with three windings, and is a commonly used power supply in industry.

Single-phase electricity refers to the circuit formed between one live wire and the neutral wire in the three-phase electricity, and its voltage is 220 volts, which is called phase voltage.

Three-phase electricity refers to the voltage loop formed between the yellow, green and red live wires, and the voltage between each line is 380 volts, which is called the line voltage.

The differences between them are:

1. The voltage is different.

220V for single phase and 380V for three phase;

2. The number of wires is different.

Single-phase is a live wire and a neutral wire, and three-phase generally refers to three live wires and a neutral wire.