1, Circuit breaker: can be switched on, bearing and breaking the normal circuit conditions of the current, can also be switched on in the specified abnormal circuit ,such as short circuit, bearing a certain time and breaking current of a mechanical switching appliance.

2、Plastic-case circuit breaker: A circuit breaker with a shell made of molded insulating material as an integral part of the circuit breaker.
3, Air circuit breaker: contact at atmospheric pressure of the air interrupt to open and close the circuit breaker

4, Vacuum circuit breaker: contact in the high vacuum tube interrupt to open and close the circuit breaker

5, Because the plastic-case circuit breaker generally uses air as the arc extinguishing medium, there is an air switch commonly known as the air switch, but the air switch is not rigorous, because the switch and the circuit breaker are two different concepts.

（二）From the function point of view, what is the difference between air switch and circuit breaker?
1, The air switch is generally in the small current circuit mainly plays the role of “isolation” and “protection device”, also called automatic switch, also called air circuit breaker.

2, The circuit breaker has a good arc extinguishing ability, in the case of short circuit current, automatic tripping; In the high voltage, high current circuit, commonly used for power failure, power supply, on, off the load of the operating appliances.