What is the difference between circuit breaker, disconnector, and load switch?

The difference between isolation switch, load switch and circuit breaker: the load switch can be broken with load and has a self-extinguishing arc function. The disconnector is generally not able to break with load, there is no arc extinguishing cover in the structure, and there is also an isolating switch that can break the load, but the structure is different from the load switch, relatively simple.

Load switch and isolation switch, can form an obvious disconnection point, most of the circuit breaker does not have the isolation function, there are also a few circuit breaker isolation function. The disconnector does not have the protection function, and the load switch has the function of overload protection. The combination of load switch and fuse can automatically trip and has some functions of a circuit breaker.

The circuit breaker can have short-circuit protection, overload protection, leakage protection and other functions. The essential difference between load switch and circuit breaker is that their breaking capacity is different, the breaking capacity of the circuit breaker can be very high in the manufacturing process, but the breaking capacity of the load switch is limited. The protection of the load switch is generally with fuse protection, only quick break and overcurrent.

The circuit breaker mainly relies on the current transformer to cooperate with the secondary equipment to protect. Load switches are mainly used in switching stations and distribution transformers with small capacity (less than 800kVA). Circuit breakers are mainly used in motors and high-capacity transformers and substations that frequently interrupt loads.

The load switch can break the normal load current and has a certain arc extinguishing capacity; The isolation switch does not have any breaking capacity, can only be broken without any load current, plays the role of isolating the electrical, he is generally installed at both ends of the load switch or circuit breaker, and plays the role of isolating the electrical when overhauling the load switch or circuit breaker; The circuit breaker has the function of breaking the accident load, and cooperates with various relay protection to protect electrical equipment or lines; The isolation switch is a switch that meets the isolation requirements in the disconnected position, and the load switch is a switch that can break the normal load current. The circuit breaker is a protective electrical isolation switch with overload, short circuit and undervoltage protection, also known as maintenance switch, which has an obvious disconnection point during maintenance; It can only be disconnected from small coincidence currents, and generally does not allow load pull isolation. The circuit breaker is generally used in the low-voltage lighting, power part, can play the role of automatic cut-off circuit, and the isolation switch is used in the high-voltage part, in the substation, the high-voltage incoming line advanced isolation switch, and then connected to the primary side of the transformer, so that the function of controlling the high-voltage incoming line on and off can be realized.

The isolation switch only isolates the equipment that has failed power to ensure that the equipment without power outage is not live. Generally, the equipment is pulled out after a power failure. Therefore, it has a simple structure, a simple control loop, and no ability to directly pull off or close the rated current.

The load switch is also used to isolate the power outage equipment and the live body, but it has a certain ability to break the rated current, but it is not very strong, and it is generally used in the load with a small capacity. It can be seen as a simple circuit breaker with a small capacity. The circuit breaker is used to directly pull off or close the rated current or even a certain degree of overcurrent, and can be used for large-capacity load circuits with strong capabilities.

The control system is complex and diverse, and the protection is comprehensive. However, it cannot be used to guarantee the isolation of blackout equipment and live bodies. In fact, the difference between these three mainly lies in the completeness of arc extinguishing ability and control protection.

They are all circuit breaking devices, but they play different roles. <>

A few simple nouns can be distinguished in three sentences. Disconnector – can only turn on and off the no-load current of the system. Because there is no arc extinguishing device, it cannot be opened and closed with a load, otherwise an arc will be generated.

Mainly in the process of electrical equipment power outage maintenance, the isolation switch is used to isolate the maintenance equipment and power supply, forming a clear disconnection point of the system to ensure the safety of maintenance personnel. Load switch - can turn on and off the normal load current of the system, but cannot automatically cut off the system fault current. Therefore, it should be used in conjunction with the fuse, and the fuse will play the role of short-circuit protection.

Circuit breaker – In addition to the normal load current of the system on and off, it can also turn on and off the fault and short-circuit current of the system. <>

1. Disconnecting switch.

It plays the role of an obvious disconnection point in the circuit to ensure the safety of personnel during maintenance, and generally can only cut off the no-load current of the line, and can not cut off the load current and short-circuit current.

The load switch also plays an isolation role, but can cut off the load current;

2. The circuit breaker can cut off the load current and short-circuit (fault) current, and can automatically trip when the fault occurs; Some models of circuit breakers also have an isolation function and can be used as an isolation appliance.

3. Contactors are divided into AC contactors.

voltage AC) and DC contactors (voltage DC), which are used in power, distribution, and consumption. Contactor in a broad sense refers to the electrical appliances that use the current flowing through the coil to generate a magnetic field and close the contact to control the load in industrial electricity.

4. The load switch is a kind of switching appliance between the circuit breaker and the isolation switch, which has a simple arc extinguishing device, which can cut off the rated load current and a certain overload current, but cannot cut off the short-circuit current.

The circuit breaker has protection components, can be operated with load, has a perfect arc extinguishing device, powerful function, can be added.

The contactor is a control element and also has an arc extinguishing device, but there is no protection function, turning the circuit on or off.

The load switch also has an arc extinguishing device, but it does not have a protection function, but it can be operated with load.

The disconnector basically has no arc extinguishing device, no protection function, and in principle, it is not allowed to operate with load, only the isolation function.

Switches are one of the most widely used devices in our daily lives, and they are also an essential part of our daily lives. At home, our most common power supply device is switch, socket, main power switch, etc., so do you know what is a load switch? So what is the difference between load switch and isolation switch?

What is a load switch.

The load switch is a kind of circuit switch device that can be disconnected and closed by itself under the normal working state of the circuit, and this load switch contains an arc extinguishing device, and its internal structure is also very simple. Such a simple sentence solves the problem of what is a load switch, I don't know if you understand it? Let's take a look at what a disconnector is.

What is a disconnect.

What is a disconnect. The disconnector is the most used and most frequently used electrical device in the coarse high-voltage switch. The disconnector is to play an isolation role in the circuit, and its internal structure is also very simple, but because it is used the most, the requirements are relatively high when working, and if it is applied to the power plant, the impact on the design and safety of the power plant is relatively large.

This is the so-called disconnector, and it's actually not that hard.

The difference between load switch and isolation switch is one.

The difference between the load switch and the disconnector is that the current cut off by the two is not the same. Because the disconnector does not have an arc extinguishing device, it is only suitable for cutting off the current of no load, and cannot cut off the load current and short-circuit current, so the electrical appliance can only be operated safely under the condition of safe disconnection of the circuit, and it is strictly operated with load, so as not to cause safety accidents. Because the load switch has an arc extinguishing device, it can overload the current and the rated load current, but it cannot cut off the short-circuit current again.

The difference between load switch and isolation switch is one.

The first point of the difference between the load switch and the isolation switch is that the load switch has an arc extinguishing device, while the disconnector does not have such a device, so what is the difference between whether there is this arc extinguishing device? The so-called arc extinguishing device is to better help the disconnection and closure of the switching appliance, and can also effectively limit the arc and help the arc to extinguish. There is such an arc extinguishing device, which is safer for switching appliances.

Therefore, most of the switching appliances are made of arc extinguishing devices. Especially switching appliances for household use.

The difference between load switch and isolation switch is three.

The role of the two is different, and this is one of the differences between load switch and disconnector. Because there is no arc extinguishing device, the isolation switch can only be used in the part of the high-voltage circuit device that needs to be charged and the part that needs to be cut off for an isolation function, so as to ensure the maintenance and inspection of the high-voltage circuit and ensure the safety of the personnel. The load switch is applied to fixed high-voltage equipment, which can cut off the fault current and rated current in high-voltage equipment, so the role of the two is different, but both are applied to high-voltage equipment.