What is the function of a vacuum load switch when it is equipped with a high voltage fuse?

Catalog of high-voltage load switches.

Introduction to the features.

Features Arc extinguishing principle.

Precautions Introduction to this paragraph.

The high-voltage load switch is an electrical appliance with a function between the high-voltage circuit breaker and the high-voltage isolation switch, and the high-voltage load switch is often used in series with the high-voltage fuse; It is used to control power transformers. The high-voltage load switch has a simple arc extinguishing device, because it can turn on and off a certain load current and overload current. However, it cannot disconnect the short-circuit current, so it is generally used in series with a high-voltage fuse, with the help of a fuse for short-circuit protection.

this paragraph].

Under the specified conditions of use, the no-load transformer of a certain capacity (315kVA indoors, 500kVA outdoors) can be turned on and off; It can connect and disconnect a certain length of no-load overhead lines (5km indoors, 10km outdoors); It is possible to turn on and off a certain length of unladen cable routes.

This paragraph] features.

a. It can isolate the power supply, has an obvious disconnection point, and is mostly used for fixed high-voltage equipment.

b. There is no arc extinguishing device, and it can pass the normal working current and short-circuit circuit in the closed state.

c. It is strictly forbidden to turn on and off the circuit with load, and it is often used in series with high-voltage circuit breakers.

This paragraph] arc extinguishing principle.

FN3-10R)--The main shaft is used to drive the piston to compress the air when the switch is opened, so that the compressed air is sprayed out at high speed from the nozzle and the arc is blown out; The FN5-10D --- is composed of an arc extinguishing tube with a complete set of arc extinguishing devices. (Vacuum tube).

this paragraph].

a. Vertical installation, switch frame, closing mechanism, cable sheath, and protective steel pipe should be reliably grounded (not connected in series).

b. Before operation, several no-load splitting and closing operations should be carried out, and each rotating part should be free of jamming, closing in place, and there should be enough safety distance after opening.

c. The melt of the fuse used in series with the load switch should be properly matched, that is, the fault current should be greater than the breaking capacity of the load switch to ensure that the melt is blown first, and then the load switch can be opened.

d. Good contact when closing, no overheating of the connection, and attention should be paid to check the dirt, cracks, porcelain dropping, and flickering discharge of the porcelain bottle during inspection; The switch cannot be flushed with water (indoor type). (When a high-voltage cabinet controls a transformer, it is best to replace the fuse to stop the circuit high-voltage cabinet.) ）

This has a blocking effect, and the effect is very good, very good.

What is the function of a vacuum load switch when it is equipped with a high-voltage fuse? What is the function of a vacuum load switch when it is equipped with a high-voltage fuse? What is the function of a vacuum load switch when it is equipped with a high-voltage fuse? What is the function of a vacuum load switch when it is equipped with a high-voltage fuse?

The high-voltage load switch refers to the power distribution system that can be closed, bearing, and bearing

In this case, the main function is to avoid machine failures.

What is the function of vacuum load switch with high current fuse? It acts as a protector.

Due to the poor breaking ability of the load switch, there is no protection ability for the fault of the power supply line. Therefore, it is generally necessary to use air circuit breakers to control the power supply lines, especially when full load breaking is required. If the requirement of full-load breaking is not required, a load switch can be used in conjunction with the fuse.

The main advantage of the use of load switch and fuse is that it is relatively cheap, especially in the case of high-voltage power supply, the high-voltage circuit breaker is usually higher, and it is more wasteful to use in the occasion of not requiring full-load breaking. The load switch is used to cooperate with the fuse, which can not only save costs, but also realize short-circuit protection and overload protection for the line. Therefore, the load switch is used in conjunction with the fuse, which is widely used in high-voltage power supply and distribution occasions.

Vacuum circuit breakers are commonly known as air switches. The load switch fuse combination is equivalent to the one with a fuse and then a knife switch in the past. The high-voltage vacuum circuit breaker is relatively advanced, which is the air opening that is commonly used now.

It has quick break, overload protection.

Compared with the load switch-fuse combination, it is more economical and simple, and it is easy to use. However, it is necessary to pay attention to the combination, and the transformer parameters should be well matched. Overload can be realized, but gas is not, it is difficult to seal, and "explosion-proof" is used.

Differences: 1. The high-voltage load switch can be broken with load and has the function of self-extinguishing arc, but its breaking capacity is very small and limited.

2. The high-voltage isolation switch is generally not able to break with load, there is no arc extinguishing cover in the structure, and there are also isolation switches that can break the load, but the structure is different from the load switch, which is relatively simple.

3. High-voltage load switch and high-voltage isolation switch can form an obvious disconnection point, most of the circuit breakers do not have isolation function, and there are a few circuit breaker isolation functions.

4. The high-voltage isolation switch does not have the protection function, and the protection of the high-voltage load switch is generally protected by fuse, and there is only quick break and overcurrent.

5. The breaking capacity of the high-voltage circuit breaker can be very high in the manufacturing process. It mainly relies on the current transformer to cooperate with the secondary equipment to protect. It can have functions such as short-circuit protection, overload protection, and leakage protection. Zhejiang Yunkai automation equipment.

Answer: A, C

This question examines the construction technology of building electrical engineering. The main function of the high-voltage fuse is to protect the Qin circuit and its equipment from short circuit and overload.

Summary. The cooperation between the fuse and the load switch can be divided into working, current and range according to the breaking current.

The cooperation between the fuse and the load switch can be divided into working, current and range according to the breaking current.

1. The load start-and-dismantle switch is a kind of switching electrical appliance between the circuit breaker and the isolation search and side-checking switch, which has a simple arc extinguishing device, which can cut off the load current and a certain overload current, but cannot cut off the short-circuit current.

2. The high-voltage load switch is an electrical appliance with a function between the high-voltage circuit breaker and the high-voltage isolation switch, and the high-voltage load switch is often used in series with the high-voltage fuse; Sakura is used to control power transformers.

3. Low-voltage load switch is also known as switch fuse group. It is suitable for AC power frequency circuits to manually turn on and off on-load circuits infrequently; Chunling can also be used for overload and slow short circuit protection of the line. The on-off circuit is completed by the contact knife, and the overload and short-circuit protection is completed by the fuse.

Hello, vacuum switch is a kind of switch that detects the vacuum range, also known as vacuum relay. Its function is: when the vacuum level generated in the actual work reaches the specified requirements of the branch, the automatic opening and closing control circuit sends out a good electrical signal to instruct the vacuum adsorption mechanism to operate normally.

It is a reliability and safety element. There are three types of vacuum switches: mechanical, semiconductor, and air bridge. Mechanical vacuum switches use mechanical displacement to determine changes in vacuum pressure, such as diaphragm vacuum switches.

Semiconductor vacuum switch uses a semi-conductive ascender pressure sensor to detect changes in vacuum pressure, and can directly convert the detected pressure signal into an electrical signal.