Indoor high-voltage vacuum circuit breaker manufacturers popularize the knowledge of circuit breakers

Indoor high-voltage vacuum circuit breaker manufacturers answer the following questions:

what is a circuit breaker?
Type of circuit breaker
The role of circuit breakers
Circuit breaker specification selection
How circuit breakers work

what is a circuit breaker?
A circuit breaker is an electrical appliance that can connect or disconnect a circuit within a certain time limit to protect equipment from damage such as overload, short circuits, and Undervoltage. The main function of the circuit breaker is to cut off and connect the load circuit. It can be used to distribute electrical energy and start and stop motors infrequently.

Type of circuit breaker
The manufacturer of indoor high-voltage vacuum circuit breakers tells you that circuit breakers are divided into frame circuit breakers, miniature circuit breakers, molded case circuit breakers, high-voltage circuit breakers, load switches, isolating switches, etc.
1. Frame circuit breaker (universal) - ACB
In terms of rated current, in principle, the rated current of 630A requires a frame circuit breaker, and the molded case circuit breaker is generally 630A (some new products can reach 1600A). It can be seen that the rated current of the frame circuit breaker is much larger, generally 630A-6300A. In addition, in terms of sectional capacity, frame circuit breakers are higher than molded case circuit breakers.

2. Miniature circuit breaker - MCB
It is one of the most widely used terminal protection appliances in building electrical terminal power distribution devices. It is used for single-phase and three-phase short circuits, overload, and overvoltage protection below 125A, including single-pole 1P, two-pole 2P, three-pole 3P, and four-pole 4P.

3. Molded case circuit breaker - MCCB
It can automatically cut off the current after the current exceeds the trip setting. Molded case circuit breakers typically contain a thermal-magnetic trip unit, while larger models are equipped with solid-state trip sensors.

Fourth, high-voltage circuit breaker (QF) - short circuit, arc extinguishing, normal load
The manufacturer of indoor high-voltage vacuum circuit breakers tells you that the high-voltage circuit breaker has a reliable arc extinguishing device, and its arc extinguishing ability is very strong. When the circuit is working, it is used to connect or cut off the load current. Accident expansion, to ensure safe operation. The high-voltage circuit breaker needs to break 1500V arcs with a current of 1500-2000A. These arcs can be stretched to 2m and continue to burn without being extinguished. Therefore, arc extinguishing is a problem that high-voltage circuit breakers must solve.

5. Load switch (QL) - overload current, simple arc extinguishing
The load switch has a simple arc extinguishing device, and its arc extinguishing capacity is limited. When the circuit is working normally, it is used to connect energy or cut off the load current, but when the circuit is open, it cannot be used to cut off huge short-circuit current.

6. Isolation switch (QS) - no arc extinguishing, there are obvious breakpoints
The isolating switch does not have a special arc extinguishing device, and its arc extinguishing ability is weak, so it is generally used to isolate the voltage, connect or cut off the circuit that has been cut off by the short circuiter and no load current flows, but cannot be used to connect or cut off the load. current.

The role of circuit breakers
A circuit breaker refers to a switching device that can close, carry and break the current under normal circuit conditions, and can close, carry and break the current under abnormal circuit conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use. The boundary between high and low voltage is relatively blurred, generally 3kV above is called high voltage electrical appliances.

Circuit breaker specification selection
How to choose the specifications and models of circuit breakers? It can be selected according to its maximum limited working current, and the type of release and accessories can be selected according to the needs of users. However, after determining the model and level, it is necessary to check whether it is consistent with the protection properties of the upper and lower switches, so as to avoid the phenomenon of leapfrog. Because if the protection properties do not match, it is easy to trip and cause safety accidents.

How circuit breakers work
When they fail (such as overload or short circuit), they can make the motor stop quickly and give an alarm signal. The action principle:

(1) The electromagnet generates a magnetic field through the coil;
(2) When the coil is energized;
(3) Pull in through the armature;
(4) When the electromagnetic force exceeds the tension of the spring;
(5) Separate the contacts;
(6) After separation;
(7) Reclose the coil;
(8) Re-suction;
(9) This cycle repeats;
(10) The purpose of breaking and connecting can be achieved;
(11) During the work process;
(12) It can be detected by a multimeter;
(13) If abnormal phenomena are found;
(14) It can be measured with an oscilloscope, etc.;
(15) and make corresponding processing.