One goes to the fitting earth circuit protective conductor (CPC), and the other to the earth rod or another kind of earth connection. An Earth-leakage circuit breaker is a safety device used in electrical installations with high Earth impedance to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. Once widely use more recent installations instead use residual current circuit breakers which instead detect leakage current directly. In case of earth leakage , a live phase may have come in contact with the device that contains it but which itself is not in contact with the groun resulting in no fault current just yet.

Offering you a wide choice of Samite and Dual Mounting , Single Phase and Three Phase as well as 3kA and 6kA Breakers. Step : switch off the main switch, earth leakage unit and all the circuit breakers , unplug everything and switch off isolators (stoves, pool, geyser, etc) Step : switch on the earth leakage unit first then switch on the main switch, if the earth leakage trips chances are you have a neutral fault, you need to call an electrician. Here we will learn designs, first using transistors only and the second using IC LM324. Means it detects the earth leakage current and makes the power supply off by opening the associated circuit breaker.
