Fire, Zero, Ground
What is single-phase two-wire, two-phase three-wire, three-phase three-wire and three-phase four-wire?
Here we talk about the two-phase three-wire system, the other are the most commonly used,
The following two diagrams are two-phase three-wire system drawings, industrial and civil design manuals on the instructions,
What is a single-phase three-wire system
The so-called single-phase three-wire system is a way of wiring electrical appliances, the three wires are the fire line L, the zero line N and the ground line PE. fire line L and zero line N are for the electrical equipment, the zero line N is the fire line. Zero line N is to provide electricity to the electrical equipment of the power circuit; the bottom line is generally connected to the shell of the electrical appliances, when there is a leakage within the electrical equipment, the shell of the equipment may be charged. If a person touches the shell, there is a possibility of electric shock. Due to the use of single-phase three-wire system, the leakage of the equipment shell will be released through the third wire, that is, the ground wire, thereby protecting the safety of the person. So often the ground line is called the protective ground line. the voltage between L and N is 220V alternating current, that is, single-phase alternating current. Civilian power supply are used single-phase AC 220V voltage supply.
The difference between one-phase two-wire system and two-phase three-wire system
One-phase two-wire refers to a firewire (also known as the phase line), a zero line (also known as the neutral line), that is, we usually use the home electricity, the voltage between the two lines is 220V, two-phase three-wire refers to two firewires and a zero line, two firewires, the voltage between the two firewires is 380 (also known as the phase voltage), any firewire and the zero voltage is 220V (also known as the phase voltage). Are 220V (also called line voltage), this situation is for each user power are larger, the use of single-phase power is obviously not enough, and the use of "three-phase four-wire" cost is relatively high, so some electricians on the use of "two-phase three-wire" system, and use the "two-phase three-wire" system. The "two-phase three-wire" system zero line can not enter the gate, can not install a fuse. If into the gate and install fuses, when the user power imbalance, the resistance suddenly increased, resulting in the zero line fused, line voltage 380 volts directly into the user, electrical appliances due to increased voltage and burned or even fire. Some electricians often do not understand the knowledge of these electrical installations, and all three wires into the gate and insurance, some users also unilaterally think that the insurance, into the gate is the most secure, I do not know that this installation, but artificially create a fire hazard, and easy to cause electrical burns and fires.
What is the two-phase three-wire wire
It is a two-phase fire wire, plus a zero wire
What is the meaning of two-phase three-wire, three-phase four-wire?
AC power is generally three-phase (phase A, phase B, phase C), two-phase three-wire refers to the A-phase, B-phase, C-phase any two-phase plus a zero line N Bean three-phase four-wire refers to the A-phase, B-phase, C-phase plus a zero line N.
Simply put: single-phase power is said to be a single-phase alternating current (AC), that is, usually referred to as the 220 volts; three-phase is said to be three-phase alternating current (AC), that is, usually referred to as the 380 volts. 380 volts; if the power equipment is useful for three-phase electricity, also useful for two-phase electricity, it must be introduced into the three-phase alternating current. For example, the family is single-phase electricity, factories, engineering public **** facilities, such as large power consumption, there is equipment introduced into the place is three-phase electricity.
What is the "two-phase, three-wire" system
A fire wire and a zero wire. In the larger capacity load place, electrical wiring installation are used
"three-phase four-wire" system, that is, three fire wire and a zero wire, each group of lighting, the average distribution.
And now, the various users of electricity are larger, the use of single-phase electricity is obviously not enough, and the use of "three
phase four wire" cost is relatively high, so some electricians use "two-phase three-wire" system, and
Using the "two-phase three-wire" system, the zero line can not enter the gate, can not install fuses. If into the gate knife
and install fuses, when the user power imbalance, the resistance suddenly increased, resulting in the zero line fused,
line voltage 380 volts directly into the user, electrical appliances due to the increased voltage and burned out or even fire
burned. Some electricians often do not understand the knowledge of these electrical installations, and will be all three wires into the gate
and installed on the insurance, some users also unilaterally think that the insurance is installed into the gate, the most secure, such as
know that this installation, but artificially create fire hazards, and easy to cause electrical appliances to burn fire. The above
fire and electrical burn accidents, is due to the housing developers will be electrical installation works contracted
to unlicensed electrician Wu, and Wu will be all three lines into the gate knife and installed fuse, zero line
fused, the voltage suddenly rises caused.
Therefore, in the "two-phase, three-wire" system installation, the zero line can not pass through the gate, and can not be installed
risk wire.
To avoid creating new fire hazards.
What is the "two-phase, three-wire" system
A fire wire and a zero wire. In the larger capacity load place, electrical wiring installation are used
"three-phase four-wire" system, that is, three fire wire a zero line, each group of lighting, the average distribution.
And now, the various users of electricity are larger, the use of single-phase electricity is obviously not enough, and the use of "three
phase four wire" cost is relatively high, so some electricians use "two-phase three-wire" system, and
Using the "two-phase three-wire" system, the zero line can not enter the gate, can not install fuses. If into the gate knife
and install fuses, when the user power imbalance, the resistance suddenly increased, resulting in the zero line fused,
line voltage 380 volts directly into the user, electrical appliances due to the increased voltage and burned out or even fire
burned. Some electricians often do not understand the knowledge of these electrical installations, and will be all three wires into the gate
and installed on the insurance, some users also unilaterally think that the insurance is installed into the gate, the most secure, such as
know that this installation, but artificially create fire hazards, and easy to cause electrical appliances to burn fire. The above
fire and electrical burn accidents, is due to the housing developers will be electrical installation works contracted
to unlicensed electrician Wu, and Wu will be all three lines into the gate knife and installed fuse, zero line
fused, the voltage suddenly rises caused.
Therefore, in the "two-phase, three-wire" system installation, the zero line can not pass through the gate, and can not be installed
risk wire. To avoid creating new fire hazards.
What is a two-phase, three-wire system and where can it be used? The voltage is 380? Please guide the experts
The standard single-phase power supply system is this. In fact, it is a three-phase, four-wire alternating current in which one of the phases is commonly known as the fire line, and the other is the zero line. Between these two wires is the line voltage that is 220V AC, and there is a wire is the protective ground, usually yellow-green.
The general building of the user line should be this structure, but now people want to save a lot of trouble are not set to protect the ground.
What is two-wire, three-wire, four-wire
The n-wire system for temperature change has two meanings:
One refers to the power supply/signal transmission method of the transmitter. Usually without explanation, a few-wire system refers to this case.
2-wire system is on a pair of wires, in the power supply at the same time signal transmission;
3-wire system is the power supply/signal each with a dedicated line, at the same time *** with a negative/ground line;
4-wire system is the power supply/signal each with two dedicated lines.
The second refers to the measurement (input) using a few wires:
Thermocouple temperature measurement usually only 2 wires;
RTD temperature measurement can be used with 2 wires, but because the resistance of the wire with the temperature changes and introduces a large error; 3, 4 wires can be very good at eliminating the influence of the temperature of the wire, but the 4-wire due to the relationship between the cost-effective and the requirements of the case will only be used in the case of very high, the industrial general 3-wire is used in industry.