How Do Different Circuit Breakers Work?

A circuit breaker is an electrical switch that cuts off dangerous or improper currents. It is a mechanical device that interrupts the flow of high-current electricity and also serves as a switch. To open or close an electrical circuit and prevent system malfunctions is the primary function of a circuit breaker. This article demonstrates the basic operation of two distinct types of circuit breakers: MCB and MCCB.

●    How An Mcb Operates

The bimetallic strip heats and bends when an excess of current flows through an MCB. When the bimetallic strip is turned, a latch is unlocked. By interrupting the circuit’s current flow, the latch disables the MCB. This method protects electrical equipment from damage caused by overcurrent or overload. The MCB must be manually switched to “ON” to restore electrical power.

A solenoid plunger is electromechanically displaced when the current rises unexpectedly in a short circuit. When the plunger hits the trip lever, the circuit breaker contacts automatically open, releasing the latch mechanism.

An MCB is a device that is easy to use and maintain. The MCBs are easily interchangeable. The trip unit is a crucial MCB component. The MCB circuit includes a bi-metal that prevents overload current and an electromagnet that prevents short-circuit current.

●    The Mccb Operating Principle

The MCCB from Legrand & IndoAsianblocks dangerous fault currents. The fault currents are interrupted via thermal and magnetic mechanisms. The thermal mechanism protects against overload, while the magnetic mechanism prevents short circuits.

●     Security Against Overloads

Overload occurs when the current exceeds a safe threshold for an extended period. The bimetallic contact in an MCCB’s thermal mechanism provides overload protection. A bimetallic strip consists of two metals, one of each type, with different thermal expansion rates. The strip lengthens or shortens depending on the temperature.

The bimetallic strip is the funnyjok primary conductor of current. The contacts will heat up and expand if the wind is too high—the strip buckles due to differential expansion and shorts out the power supply.

It is normal for electrical devices to experience temporary overloads in current, and this should not be interpreted as fault current. MCCBs delay tripping the circuit during an excess to allow current to build up.

●    Safeguards Against Short Circuits

The solenoid in a moulded case circuit breaker generates electromagnetic force to counteract any potential damage from a short circuit. The solenoid is the primary current path, attracting and repelling the plunger that ultimately trips the breaker.If the current is too low, the solenoid will generate a weak magnetic force, and the plunger will not be attracted. The high current flowing through the solenoid during a short circuit produces a powerful magnetic field.


House electrical current follows a complex diagram of many smaller circuits. The hotline connects to the power plant at one end of the system. Due to the thestyleplus hotline’s energy, charge flows when the circuit diagram is closed. This section introduces alternating current because it immediately changes direction. Legrand & IndoAsian‘s website have information about a circuit breaker.

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