Classification and Selection of Circuit Breakers

The circuit breaker manufacturer will introduce the classification and selection of circuit breakers for you.
Classification and Selection of Circuit Breakers by Circuit Breaker Manufacturers
1. High-voltage circuit breaker (QF) – short circuit, arc extinguishing, normal load
The high-voltage circuit breaker is equipped with a reliable arc-extinguishing device, which has a strong arc-extinguishing capability. When the circuit is operating normally, it is used to connect or disconnect the load current. When a fault occurs in the circuit, it prevents the accident from escalating and ensures safe operation. It can also be used to cut off huge short-circuit currents. To break an arc with a voltage of 1500V and a current of 1500-2000A, these arcs can be stretched up to 2 meters and still continue to burn without extinguishing. Therefore, arc-extinguishing is a problem that the high-voltage circuit breaker must solve.
High-voltage circuit breakers can be classified according to the different arc-extinguishing media into multi-oil arc-extinguishing circuit breakers, low-oil circuit breakers, high-voltage circuit breakers, vacuum circuit breakers, sulfur hexafluoride circuit breakers, and magnetic blowout circuit breakers, etc.
2. Load Switch (QL) – Overload current, simple arc extinguishing
The interrupter of a load switch has a simple arc-extinguishing device. Its arc-extinguishing capability is limited. When the circuit is operating normally, it is used to connect or cut off the load current. However, when the circuit is open, it cannot be used to cut off the huge short-circuit current. After the load switch is disconnected, there is a visible break point, which is its characteristic.
3. Isolating Switch (QS) – No arc extinguishing, with a distinct break point
The isolating switch does not have a special arc-extinguishing device and its arc-extinguishing capability is weak. Therefore, it is generally used to isolate voltage, connect or disconnect circuits that have been cut off by the circuit breaker and have no load current flowing through, but cannot be used to connect or cut off load current. The main purpose of the isolating switch is to isolate the power supply voltage when electrical equipment needs to be repaired and to create an obvious break point to ensure the safety of the maintenance personnel.
The manufacturers of circuit breakers usually install circuit breakers for capacities exceeding 400 KVA, or vacuum load switches. Those with capacities below this are equipped with pressure gas load switch fuse combination units, which use fuses to cut off overcurrent. Moreover, the fuses have impactors! When the fuse operates, the load switch will trip!