How is earth leakage typically detected in electrical systems?

Earth leakage is commonly detected by Residual Current Devices (RCDs), which are specifically designed for this purpose. RCDs monitor the current flowing through live and neutral wires. Under normal circumstances, the current remains balanced between these two wires. However, if there is a leakage current, indicating that some of the electrical current is escaping to the ground, the RCD detects this imbalance. When it senses that the current is not equal, typically at levels as low as 30 milliamps, it quickly disconnects the circuit to protect against electric shock or fire.

This feature makes RCDs extremely effective for ensuring safety in electrical installations, especially in areas where moisture is present, such as bathrooms or kitchens, where there's an increased risk of electric shock. RCDs are capable of functioning independently of circuit breakers, providing an additional layer of safety in electrical systems.