Leakage circuit breaker is an essential safety device in electrical systems. Its main function is to protect personnel and electrical equipment from the hazards of electric leakage. When a circuit experiences leakage current, the residual current circuit breaker will quickly detect this imbalance when the current flowing through the live wire is not equal to the current returning through the neutral wire. For example, in household appliance settings, if a faulty appliance experiences leakage current due to insulation damage or short circuit, the RCCB will detect this abnormal current. Once the leakage current exceeds a certain threshold, usually a few milliamps, the RCCB will immediately cut off the power supply. This rapid response is crucial as it can prevent people who may come into contact with the faulty circuit from getting electrocuted. It can also protect electrical equipment from damage caused by excessive leakage current, which may lead to overheating and potential fires. In addition to providing protection against electric shock and fire hazards, some RCCBs also have other functions. For example, they may have test buttons that allow users to periodically check the functionality of the device. Some models also have indicators to display whether the RCCB is in normal working condition. Overall, residual current circuit breakers play a crucial role in ensuring the safety of electrical installations and protecting life and property by detecting and preventing leakage.