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Molded Case Circuit Breakers (MCCBs): Ensuring Electrical Safety

Exporelec > Blog > Electric > Molded Case Circuit Breakers (MCCBs): Ensuring Electrical Safety
Dec 22, 2023 Posted by: Exporelec Electric Electric

Understanding MCCBs

Molded Case Circuit Breakers (MCCBs) stand as a type of low-voltage circuit breaker, serving as automatic electrical devices to shield electrical equipment from overload, short circuits, instantaneous overcurrents, and earth faults. An advanced iteration of the MCB (Miniature Circuit Breaker), the MCCB spans a broad range, catering from 16 Amps to 1600 Amps.

Versatility and Application Range

With their extensive current ratings and high breaking capacity, MCCBs find wide application in industrial settings. They’re instrumental in protecting capacitor banks, ensuring generator safety, and serving as the primary electric feeder distribution safeguard. Their applicability extends even to home settings, handling higher current ratings and fault levels

Operational Mechanism

Employing a combination of a temperature-sensitive device (the thermal element) and a current-sensitive electromagnetic device (the magnetic element), MCCBs facilitate the trip mechanism for protection and isolation functions. This enables MCCBs to offer overload protection, shield against electrical faults during short circuit currents, and serve as an electrical switch for disconnection.

Selection Criteria for MCCBs

When integrating MCCBs into an electrical circuit, their selection relies on the circuit’s anticipated nominal operating current and potential short-circuit fault currents. The primary criteria for MCCB selection are as follows:

Correspondence of the MCCB’s rated operating voltage with the system voltage.

Configuring the MCCB’s trip value in alignment with specific applications.

Ensuring the breaking capacity of the MCCB exceeds the theoretical maximum short-circuit fault currents.

Accessories for MCCBs

Several accessories complement MCCBs, extending additional functionalities or indicating control voltage. These accessories encompass:

Rotary Handle (Extended/Direct)

Motorized Operation

Manual/Auto Operation

Mechanical Interlocking

Shunt Trip

Alarm Contact

Under Voltage Trip

Auxiliary Contact