Circuit breakers are essential components of electrical systems, designed to protect against overcurrents, short circuits, and other electrical faults by interrupting the flow of electricity when necessary. There are various types of circuit breakers available, each designed for specific applications and operating conditions. Here are some common types of circuit breakers:

1. Miniature Circuit Breaker (MCB):

   • MCBs are commonly used in residential and commercial electrical installations to protect against overloads and short circuits.
   • They are compact, economical, and available in various current ratings and trip characteristics.
   • MCBs typically have a toggle switch for manual operation and provide quick and convenient resetting after tripping.

2. Molded Case Circuit Breaker (MCCB):

   • MCCBs are designed for higher current applications in commercial and industrial settings.
   • They offer adjustable trip settings, thermal and magnetic protection, and higher breaking capacities compared to MCBs.
   • MCCBs are available in various frame sizes and can provide protection against overloads, short circuits, and ground faults.

3. Air Circuit Breaker (ACB):

   • ACBs are used for high-voltage applications, typically above 1 kV, in industrial and commercial power distribution systems.
   • They employ air as the arc extinguishing medium and offer adjustable trip settings, thermal and magnetic protection, and high breaking capacities.
   • ACBs are available in various configurations, including fixed, draw-out, and withdrawable types, for ease of maintenance and operation.

4. Oil Circuit Breaker:

   • Oil circuit breakers use oil as the arc extinguishing medium and are commonly used for medium-voltage applications.
   • They provide reliable performance and high breaking capacities, making them suitable for outdoor installations and harsh environments.
   • Oil circuit breakers require regular maintenance to ensure the integrity of the oil and insulation.

5. Vacuum Circuit Breaker (VCB):

   • VCBs use a vacuum as the arc extinguishing medium and are widely used for medium and high-voltage applications.
   • They offer fast interruption, minimal maintenance requirements, and high breaking capacities, making them suitable for critical power systems.
   • VCBs are commonly used in substations, industrial plants, and electrical distribution networks.

6. Sulfur Hexafluoride (SF6) Circuit Breaker:

   • SF6 circuit breakers use sulfur hexafluoride gas as the arc extinguishing medium and are employed for high-voltage applications.
   • They offer excellent dielectric properties, high breaking capacities, and compact designs.
   • SF6 circuit breakers are commonly used in electrical substations, transmission lines, and power generation facilities.

7. Residual Current Circuit Breaker (RCCB) / Ground Fault Circuit Interrupter (GFCI):

   • RCCBs/GFCIs provide protection against ground faults and electric shock hazards in residential and commercial installations.
   • They detect imbalance in current flow between the live and neutral conductors and trip the circuit when leakage current exceeds a predetermined threshold.
   • RCCBs/GFCIs are essential for ensuring electrical safety in wet or damp environments, such as bathrooms, kitchens, and outdoor areas.

These are some of the common types of circuit breakers used in electrical systems, each offering specific features, capabilities, and applications. The selection of the appropriate circuit breaker depends on factors such as voltage rating, current rating, breaking capacity, environmental conditions, and regulatory requirements.