1. Introduction to "circuit breaker"
1.1 What is a "circuit breaker"
A circuit breaker is a switching device that can close, carry and break current under normal circuit conditions and can close, carry and break 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 division of high and low voltage boundaries is relatively vague. Generally, those above 3kV are called high-voltage electrical appliances.
1.2 Main functions of the circuit breaker
The characteristics of the circuit breaker mainly include: rated voltage Ue; rated current In; overload protection (Ir or Irth) and short-circuit protection (Im) tripping current setting range; rated short-circuit breaking current (industrial circuit breaker Icu; household circuit breaker Icn )wait.
2. Specifications and models of DEDUN circuit breakers
DEDUN is generally divided into colors: white, transparent, etc.
The circuit breaker is also divided into several P, some people say several poles. 1P, 2P, 3P, 4P, etc. According to the number of poles: there are single pole, two poles, three poles and four poles, etc.;
According to the installation method: there are plug-in type, fixed type and drawer type.
Three circuit breakers related introduction
The circuit breaker symbol, the symbol of the circuit breaker is QF
Circuit breaker in English, circuit breaker (English name: circuit-breaker, circuit breaker) refers to the ability to close, carry and break the current under normal circuit conditions and can close, carry and break abnormal circuit conditions within a specified time under the current switching device.
According to IEC 61636-1, it is not an English abbreviation, but a combination of letter meanings. Q:Switching device for power circuit power circuit switching equipment, F: Protection device protection equipment, QF: circuit breaker.
The difference between four circuit breakers and isolating switches
The symbol of the disconnector is QS and the symbol of the circuit breaker is QF
The isolating switch is a switching device that is mainly used to "isolate power supply, switch operation, connect and cut off small current circuits", and has no arc extinguishing function. A circuit breaker is a switching device capable of closing, carrying and breaking current under normal or abnormal circuit conditions.
The difference between a circuit breaker and a circuit breaker
1. The circuit breaker is equipped with arc suppression equipment and can trip by itself, so it can cut off the current of resistance and obstacles; while the air switch is not equipped with arc suppression equipment, so it cannot be used to cut off the current of resistance and obstacles.
2. In terms of operation, the circuit breaker can be electrically controlled far away; while the air switch is mostly manually controlled.
3. The insulation level of the interface of the circuit breaker is low, so it is usually used to deal with resistance and obstacle current; while the ability of overvoltage is very weak, and the interface insulation level of the air switch is very high, which is usually used to deal with voltage and cannot be handled resistance and barrier currents.
4. The circuit breaker can protect the current circuit and the motor, and disconnect the obstacle current; while the air switch usually has an isolation effect and operates without resistance.
5.3 The insulation level of the circuit breaker has nothing to do with the rated voltage
This statement is wrong.
DEDUN switch socket tells you that a circuit breaker is a kind of electrical equipment, and its insulation level should of course be based on its rated voltage when designing, that is, it is determined by its rated voltage. Therefore, it is wrong to say that the insulation level of a circuit breaker has nothing to do with the rated voltage of the circuit breaker.
5.4 Is the rated on-off of the circuit breaker required when selecting the circuit breaker?
DEDUN switch socket tells you that this statement is wrong. The breaking capacity of the circuit breaker should be greater than or equal to the maximum fault current in the line.
1. First choose according to the rated voltage, and the rated voltage should be consistent.
2. The rated current of the circuit breaker must be greater than or equal to the rated current of the circuit used.
3. The rated breaking current of the circuit breaker should be greater than or equal to the short-circuit current of the circuit used.
4. Choose according to environmental conditions, such as altitude, temperature, humidity, and choose a circuit breaker that meets the requirements.
5. Select a circuit breaker with high quality and high cost performance according to the brand.
6. For special breaking conditions, check the circuit breaker. However, different loads should choose different types of circuit breakers.
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