Types of Circuit Breakers and Their Applications

Types of Circuit Breakers and Their Applications

1. MCB (Miniature Circuit Breaker)

MCBs are commonly used in residential and commercial electrical systems for the protection of low-voltage circuits. They provide automatic disconnection in the event of an overload or short circuit. Unlike fuses, MCBs can be reset after tripping. They are generally rated for currents up to 125A.

2. ELCB (Earth Leakage Circuit Breaker)

ELCBs are designed to detect earth faults and leakage currents. They protect against electric shocks and prevent fire hazards caused by insulation failure. These breakers are particularly useful in environments where electrical safety is a priority, such as homes, hospitals, and industries handling sensitive equipment.

3. RCCB (Residual Current Circuit Breaker)

RCCBs are used to detect and disconnect electrical circuits when there is a leakage current exceeding a predetermined value. Unlike MCBs, which respond to overcurrent and short circuits, RCCBs specifically address residual currents that could lead to electrocution or fire. These devices are typically used in combination with MCBs for comprehensive circuit protection.

4. MCCB (Molded Case Circuit Breaker)

MCCBs are designed for higher current ratings and are typically used in industrial and commercial applications. They offer protection against overloads, short circuits, and under-voltage conditions. MCCBs are available in ratings ranging from 100A to several thousand amperes, making them suitable for large electrical installations.

5. ACB (Air Circuit Breaker)

Air Circuit Breakers use air as an arc extinguishing medium and are commonly used in high-power applications such as power distribution panels and industrial systems. They provide reliable protection for electrical equipment operating at low and medium voltages. ACBs are preferred for their ability to handle high currents and multiple operational cycles.

6. VCB (Vacuum Circuit Breaker)

Vacuum Circuit Breakers utilize vacuum as the arc extinguisher to interrupt an electrical circuit. 

Used in medium and high-voltage power systems, including substations and transmission networks. 

When a fault or over-current occurs, the VCB uses a vacuum to interrupt the flow of electricity. 

Known for high interruption capability, long operational life, safety, and good cost-performance. 

The actuator mechanism forces the movable contact to break the connection with the fixed contact, creating an electrical arc between the two contacts.