A lot of content related to molded case circuit breakers has been introduced earlier, do you know the working principle of molded case circuit breakers?

Plastic case circuit breakers are generally composed of a contact system, an arc extinguishing system, a working mechanism, a trip and a housing.

When short-circuiting, the magnetic field generated by the high current (generally 10 to 12 times) overcomes the counterforce spring, the tripper pulls the working mechanism into action and the switch trips instantly. It is important to note that when overloading, the current becomes high, the heating increases and the bimetallic fragments push the mechanism into motion to a certain extent, so the higher the current, the shorter the movement time. There are electronic circuit breakers that use transformers to collect the magnitude of the current in each phase. When the current is abnormal compared to the set value, the microprocessor sends a signal to the electronic tripper to move the working mechanism.

The function of the moulded case circuit breaker is to cut off and connect the load circuit, cut off the faulty circuit, prevent the accident from expanding and ensure safe operation. High voltage circuit breaker to cut off 1500V, the current is 1500A-2000A arc, this arc increases to 2 meters will not be extinguished, can continue to burn. Therefore, the elimination of the arc is a high-voltage circuit breaker must solve the big problem.

The principle of blowing the arc to pull the arc is mainly to cool the arc to weaken the heat, on the other hand, blowing the arc to lengthen the arc, strengthen the compound and spread of electric particles, while blowing charged particles in the arc seam to quickly restore the insulation strength of the medium.

Low voltage moulded case circuit breakers, also known as automatic air switches, can be used to connect and cut off load circuits, as well as to control motors that are not always started. It is the sum of some or all of the functions of appliances such as brake switches, overcurrent relays, voltage loss relays, thermal relays and earth leakage protectors, and is an important protective device in low-voltage distribution networks.

Low-voltage moulded-case circuit breakers have a variety of protection functions such as overload, short-circuit and low-voltage protection, with the advantages of controllable action values, high interception capacity, easy operation and safety, etc. They are now widely used. Structure and working principle of low-voltage circuit breaker consists of working mechanism, contacts, protection devices (various tripping), arc extinguishing system, etc.

The main contact of the low-voltage plastic circuit breaker is closed by manual operation or drive. After the main contact is closed, the free separation mechanism locks the main contact in the closed position. The coil of the overcurrent trip and the thermal component of the thermal tripper are connected to the main circuit and the coil of the low-voltage trip is connected in parallel to the power supply. If a short circuit or severe overload occurs in the circuit, the armature of the overcurrent tripper will engage, the free tripping mechanism will operate and the main contacts will cut the main circuit. When the circuit is overloaded, the thermal element of the thermal tripper thermally bends the bimetal and pushes the free tripping mechanism into motion. When the circuit voltage is insufficient, the armature of the low voltage dehydrator is released. It also makes the movement of the free deduction mechanism possible. The actuator is used for distance control, the coil is disconnected during normal operation, the start button is pressed to power the coil when distance control is required and the armature drives the free tripping mechanism to separate the main contacts.

It is about the structural composition and working principle of low voltage moulded case circuit breakers. This brief introduction provides a brief insight into this area of knowledge. If you encounter any problems related to circuit breakers, you can consult the website or Taisi Electric customer service.