Circuit breakers vary by function and application: MCB for overload/short circuit; RCCB for earth leakage; Wi-Fi breaker for smart control; MCCB for higher currents; ELCB (legacy) for shock protection; ACB, VCB, BOCB, SF6, and MPCB serve specific voltage, medium, or motor-protection needs.

Breaker Failure Protection (50BF) trips adjacent breakers if the primary breaker fails to open after a fault, using trip initiation, auxiliary contact status, and residual current detection.

Directional earth-fault relay (67N) uses residual current and broken-delta voltage for protection; core-balance CT is preferred in high-impedance grounded systems; RCA sets torque angle relative to polarizing voltage.

Relay coordination is a fundamental aspect of power system protection, ensuring that only the faulted section is isolated while the rest of the network continues operating reliably. It is essential for equipment safety, system stability, and minimizing power outages.