How to classify Miniature circuit breaker

How to classify Miniature circuit breaker

An overview of the Miniature circuit breaker

Miniature circuit breaker is the most important protection and control in Miniature circuit breaker components, one of the mainly used in industrial and mining enterprises, high-rise buildings, hotels, hospitals, airports, docks, and in the low voltage distribution network in the modern residential area, used for protection of ac/dc electrical equipment, make against over current, reverse current, short circuit, undervoltage anomalies such as damage, It can also be used infrequently to start motors and operate conversion circuits. Intelligent low-voltage electrical appliances are more suitable for the centralized control of automated substations and modern power grids.

Classification  

(1) According to the type of current, it is divided into AC and DC

(2) Air is divided according to arc extinguishing medium; A vacuum; Gas (rarely used in low voltage circuit breakers)

(3) By use category

Class A: in the case of short circuit, the circuit breaker does not clearly specify the selective protection of another short circuit protection device used in series on the load side, that is, in the case of short circuit, there is no artificial short delay required for selective protection, so there is no short-time tolerance current requirements.

Class B: in the case of short circuit, the circuit breaker clearly indicates the selective protection of another short circuit protection device in series on the load side, that is, in the case of short circuit, selective protection can be achieved, and some people for short delay (adjustable), so there is a short-time tolerance current requirements.

(4) According to the structure type

Universal type: referred to as ACB, all parts are installed in an insulating or metal frame, there are more structural changes, more kinds of tripping device, more number of auxiliary contacts, general selective circuit breaker, especially large capacity circuit breaker, more design into universal type.

Plastic case: referred to as MCCB or plastic case, all parts are housed in an insulated case. Plastic case circuit breakers are compact, small in size, light in weight, low in price, and safer to use (the operator is less likely to contact conductive parts), suitable for independent installation. Because its rated current is small, the non - selective circuit breaker is mostly designed as a plastic case.

(5) According to the protection device

Hot type: mostly bimetal type, but also three metal type

Electromagnetic type: iron core with coil, used for instantaneous tripping device or as backup protection

Electronic: the use of electronic components of the release device

Intelligent: the release device is composed of microprocessor, which can achieve various protection characteristics

Communication intelligent: with intelligent release, increase interface and field bus, can support a variety of communication protocols, two-way communication.

(6) according to the principle of action

Current limiting type: the use of short-circuit current repulsive effect, so that the contact quickly open, break, can not appear in the first peak peak when the short-circuit current is broken.

Unrestricted-current type: generally for industrial use, can break the expected short-circuit current.

(7) According to breaking speed

General type: action time above 20ms, generally for industrial use

Fast type: action time in 10~20ms, mostly used for DC

(8) by use

Residual current protection circuit breaker; No overcurrent protection circuit breaker CBI; Instantaneous action circuit breaker ICB;

Distribution circuit breaker: used to protect power circuits and electrical equipment from short-circuit and overload hazards

Special circuit breaker for motor protection: specially used to protect starting motors

Circuit breaker for special purpose: for example, a circuit breaker with out magnet

No overcurrent protection circuit breaker CBI and instantaneous action circuit breaker ICB seem to differ little. The former can be completely free of overcurrent (overload and short circuit) tripping device, suitable for use as isolators. The latter with instantaneous action tripping device, in addition to the isolator, emphasized with the motor protection device and other over-current protection device with the task of the circuit breaker is to do backup protection.