What is the strong and weak electricity, why should the wiring be separated?

I believe many people will have this confusion: What is strong electricity and what is weak electricity? What is the difference between the two? Why should the power and weakness be separated when wiring? Let us introduce it now.

Strong electricity

The concept of strong electricity is generally not related to the specific limits of voltage and current.

People in the electronic world are accustomed to two parts: strong electricity (electricity) and weak electricity (information). The two have the sameities and differences. Generally speaking, the object of high-power processing is energy (electricity), which is characterized by high voltage, large current, high power and low frequency. The main consideration is to reduce losses and improve efficiency. The processing object of weak electricity is mainly information, that is, the transmission and control of information, which is characterized by low voltage, small current, low power and high frequency. The main consideration is the effect of information transmission, such as the fidelity and speed of information transmission. , breadth, reliability. In general, weak current projects include television engineering, communications engineering, fire engineering, security engineering, imaging engineering, etc., and integrated wiring engineering for the above projects. Weak electricity is for strong electricity. Strong electricity = (380/220), high voltage regardless.

In the power system, the voltage below 36v is called the safety voltage, the voltage below 3kv is called the low voltage, the voltage above 3kv is called the high voltage, and the line directly supplying the power to the user is called the distribution line. For example, the user voltage is 380/220v. It is called the low-voltage distribution line, which is the strong electricity mentioned in the home decoration. Strong power generally means that the AC voltage is above 24V. Such as electric lights, sockets, etc. in the home, the voltage is 110V~220V. Household electrical appliances such as lighting fixtures, electric water heaters, heaters, refrigerators, televisions, air conditioners, and audio equipment are all strong electrical equipment.

The intelligent system is a comprehensive system composed of construction equipment monitoring system, security defense system, communication network system, information network system, fire automatic alarm and fire linkage, etc., with the purpose of centralized monitoring, control and management; various data collection in the family. Control, management, and communication control or network systems are called intelligent lines (that is, weak electricity in home decoration). Weak current generally refers to DC circuit or audio, video line, network line, dian line, DC voltage is generally within 24V. The electrical input devices (cable line) and audio equipment (output line) in household electrical appliances are all weak electrical equipment.

Weak current

Weak current generally refers to DC circuit or audio, video line, network line, dian line, DC voltage is generally within 32V. The electrical and electronic equipment such as the signal input (cable line) and audio equipment (output line) of computers and televisions in household appliances are weak electrical equipment.

There are two main types of weak electricity in buildings: one is the nationally specified safe voltage level and the low voltage electric energy such as the control weak current voltage. There are AC and DC points, such as 24V DC control power supply or emergency lighting standby power supply. The other type is information sources that contain information such as voice, images, and data, such as television and computer information.

The weak construction of buildings in the narrow sense mainly refers to: security (monitoring, perimeter alarm, parking lot), fire protection (electrical part), building control, and network cabling and audio systems.

The difference between weak electricity and strong electricity

Conceptually, strong and weak electricity are generally easy to distinguish. The main difference is the difference in use. Strong electricity is used as a kind of power source, and weak electricity is used for information transmission. They have roughly the following differences:

1, the exchange frequency is different

The frequency of strong electricity is generally 50 Hz (hertz), which is called "power frequency", which means the frequency of industrial electricity: the frequency of weak electricity is often high frequency or ultra high frequency, measured in KHz (kilohertz) and MHz (megahertz).

2, different transmission methods

Strong power is transmitted on transmission lines, and weak power transmission is divided between wired and wireless. The radio is transmitted by electromagnetic waves.

3. Power, voltage and current are different in size

4, classification

There are two main types of weak current in buildings: one is the low voltage electric energy such as the safety voltage level and control voltage specified by the state, and there are AC and DC points, such as 24V DC control power supply or emergency lighting standby power supply. The other type is information sources that contain information such as voice, images, and data, such as television and computer information.

5, function and application

According to the strength of power transmission power, power applications can be divided into two types: strong power and weak power. Electricity for buildings and buildings generally refers to strong electricity with AC 220V50Hz and above. It mainly provides people with electric energy and converts electric energy into other energy sources, such as air conditioning, lighting, power and so on.

There are two main types of weak electricity in intelligent buildings. One is low-voltage electric energy such as safety voltage level and control voltage specified by the state. There are AC and DC points, AC below 36V, DC below 24V, such as 24V DC control power supply, or emergency. Lighting backup power supply. The other type is information sources that contain information such as voice, images, and data, such as television and computer information.

People are accustomed to calling the technology of weak currents a weak current technology. It can be seen that the basic meaning of smart building weak technology is still the weak technology in the original sense. However, with the rapid development of modern low-tech high-tech, the application of weak current technology in intelligent buildings is more and more extensive. In general, weak current system engineering refers to the second type of application.

mainly include:

1. TV signal engineering, such as TV monitoring system, cable TV.

2. Communication engineering.

3. Intelligent fire protection engineering.

4, sound reinforcement and sound engineering, such as the background music broadcast in the community, the background music in the building.

5. Integrated wiring engineering, mainly used in computer networks. With the rapid development of computer technology, the software and hardware functions are fast and powerful, and the perfect combination of various weak current system engineering and computer technology makes the previous classifications less clear than before. The integration of various types of projects is system integration.

Common weak current system operating voltages include: 24VAC, 16.5VAC, 12VDC, and sometimes 220VAC is also considered a weak system. For example, some cameras operate at 220VAC, and we cannot classify them into high-power systems. The weak current system is mainly for buildings, including buildings, communities, airports, terminals, railways, highways, etc.

Common weak current systems include: closed circuit television monitoring system, burglar alarm system, access control system, electronic patrol system, parking management system, video intercom system, home intelligent system and security system, background music system, LED display system, Plasma splicing screen system, DLP large screen system, three meter copying system, building automation system, lightning protection and grounding system, paging intercom and professional intercom system, weak electric pipeline system, UPS uninterruptible power supply system, computer room system, comprehensive Wiring system, computer LAN system, property management system, multi-functional conference room system, cable TV system, satellite communication system, fire protection system, communication system, hotel management system, video on demand system, human resource management system, etc.

Why is the difference between strong and weak?

Distinguish between strong and weak electricity is because there is no common slot between strong and weak power, otherwise it will interfere with the transmission of weak electricity information, affect the use of TV and computer in the home, and may even cause fire.

Then, in the construction of strong and weak electricity, how to avoid the interference of weak electricity, and what specific precautions in the line layout, there are five main points:

1, strong and weak electricity to be separated

In the decoration, the most taboo thing in the circuit wiring transformation is to put all the lines together. Therefore, when renovating the circuit construction, the national standard is: strong and weak electricity should be separated and routed, and the common box should not be shared, and the parallel distance between the strong and weak electricity should not be less than 30cm. However, considering the actual situation (the modern apartment does not meet the conditions of 30cm or more), some decoration companies will leave at least 15cm to ensure the distance. This distance also ensures that there will be no strong electrical interference with weak currents.

2, different weak wires should also be separated

Different weak wires together will also cause signal interference. To avoid this situation, weak wires such as network cables and TV cables must be separately piped when working in the line. Do not share the same pipe.

3, the wiring is in front of the line behind

Whether it is strong or weak, in the wiring construction, the rules of installing the pipeline and then threading should be followed. This is to prevent the phenomenon that it cannot be twitched, and it is convenient to carry out maintenance and change lines in the future.

4, the same line within the tube should not be too much

When laying strong and weak electric lines, the number of required pipes should be changed according to the number of wires. In principle, one pipe cannot exceed four wires, and there must be no wires to fill the space inside the pipe. Like the general elbow utilization rate between 40% and 50%, the straight tube can be slightly higher, between 50% and 60%.

5, avoid avoiding broken right angle bend

In the construction line, when the line needs to turn, it must not have a broken right angle. This may affect the signal strength and cause the wire to pass through. Therefore, try to use large bends and metal angles. Come over the connecting wire.