Mechanism Involved in Molded Case Circuit Breaker

Moulded case circuit breaker, or MCCBs, is devices that are used to protect the electrical circuit from excessive current, which can even cause overloads or short circuits. For a wide range of voltages and frequencies, there is the use of molded case circuit breaker along with adjustable trip settings. To provide the trip mechanism protection and isolation the MCCB utilizes a temperature-sensitive device with a current-sensitive electromagnetic device. In addition to tripping mechanisms, we can also use MCCBs as manual disconnection switches in case of any emergency or maintenance operations.

MCCB

Molded Case Circuit Breaker is a type of circuit breaker that protects the circuit from current surges, short circuits, and overloading. It serves as an advanced version of a miniature circuit breaker that operates similarly. However, it also provides extra features that establish it as a superior circuit breaker such as remote closing and adjustable trip settings. This indicates that the current settings and time settings can be adjusted according to our needs. Moulded Case Circuit Breaker Manufacturer makes these circuits keeping in mind certain details related to their mechanism.

Arc Chute

Arc chute can be described as a set of parallel metal plates that are mutually insulated from each other. It extinguishes the arc just by splitting the arc and lengthening it. It is also referred to as an arc divider or arc splitter. These plates are prepared from ferromagnetic material.

Contacts

Contacts are the metallic conductors that help in carrying the current to the load. There are two different types of contacts i.e., fixed and moving contact. The contacts are prepared from arc resistance material that has low resistivity and corrosion. The sustainability of the circuit breaker is decided by the quality of the material.

Magnetic Trip Unit

The magnetic trip unit consists of a relay that generates a magnetic field when there is the flow of higher currents through its solenoid due to the short circuit. It then causes tripping of the circuit breaker.

Operating Mechanism

It operates on the mechanism of MCCB which is responsible for opening and closing the current-carrying contacts. It has a connection with a trip unit that provides a trigger to the operating mechanism. The operation of the trip unit is based on a thermal and magnetic mechanism.

Trip Unit

It is the trip unit that is responsible for triggering the operating mechanism. The trip unit consists of a thermal mechanism for overload, magnetic tripping for short circuits, and a test button for testing purposes.

Thermal Trip Unit

The thermal trip unit makes use of a thermal mechanism which is a bimetallic strip that gets bends when the temperature increases because of overloading.

Terminal Connector

The use of a terminal connector is to connect MCCB Circuit Breaker with the external circuit. The upper terminals have a connection to the output/load whereas the bottom terminals are connected to the input/supply. However, they are bidirectional but the input and output designation is basically because of their physical installation.