A mini circuit breaker, commonly referred to as MCB, is a compact electrical safety device designed to automatically cut off the power supply when an overload or short circuit occurs in a circuit. It plays a crucial role in protecting people, appliances, and electrical systems from the dangers of excessive current. Unlike traditional fuses that melt when the current exceeds a safe level, an MCB is designed to switch off instantly and can be reset with a simple toggle, making it both reliable and convenient.