What does circuit breaker pollution rating mean

It refers to the kind of environment in which it can be used.

For example, Level 3 refers to: industrial environment.

The standard is: IEC 60947-1

It is the meaning of specifying what kind of environment it can be used in.

Circuit breaker (English name: circuit-breaker, circuit breaker) refers to a switchgear 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.

The circuit breaker can be used to distribute electric energy, start the asynchronous motor infrequently, protect the power supply line and the motor, and automatically cut off the circuit when they have serious overload or short circuit and undervoltage and other faults, and its function is equivalent to the combination of fuse switch and over/underheat relay. In addition, it is generally not necessary to change the parts after the fault current is switched off. At present, it has been widely used.

Mainly according to the performance of the switch, each brand is not necessarily the same, the general micro circuit breaker is divided into equal. Molded case circuit breakers are generally 25ka, 36ka, 50ka, 80ka, 100ka, etc. The frame is generally more than 50ka, 65ka, 80ka, etc., of course, it depends on whether the voltage level is in the case of 415V or 690V.

The circuit breaker can be used to distribute electric energy, start the asynchronous motor infrequently, protect the power supply line and the motor, and automatically cut off the circuit when they have serious overload or short circuit and undervoltage and other faults, and its function is equivalent to the combination of fuse switch and over/underheat relay. In addition, it is generally not necessary to change the parts after the fault current is switched off.

How circuit breakers work.

The circuit breaker is generally composed of a contact system, an arc extinguishing system, an operating mechanism, a tripper, a shell, etc.

When there is a short circuit, the magnetic field generated by the high current (generally 10 to 12 times) overcomes the reaction spring, the tripper pulls the operating mechanism to act, and the switch trips instantaneously. When overloaded, the current becomes larger, the heat generation intensifies, and the bimetal sheet deforms to a certain extent to push the mechanism to act (the larger the current, the shorter the action time).

If there is an electronic type, the transformer is used to collect the current of each phase, and compared with the set value, when the current is abnormal, the microprocessor sends a signal to make the electronic tripper drive the operating mechanism to act. The function of the circuit breaker is to cut off and turn on the load circuit, as well as cut off the fault circuit, to prevent the expansion of the accident and ensure safe operation. The high-voltage circuit breaker should break the arc of 1500V and the current is 1500-2000A, which can be stretched to 2m and continue to burn without extinguishing.

Therefore, arc extinguishing is a problem that must be solved by high-voltage circuit breakers. On the other hand, the arc blowing and elongating the arc strengthens the recombination and diffusion of charged particles, and at the same time blows away the charged particles in the arc gap to quickly restore the dielectric strength of the medium.