ELCB

An Earth Leakage Circuit Breaker, commonly known as an ELCB, is a safety device designed to protect electrical circuits from earth faults. It operates by monitoring the current flowing through live and neutral conductors. If an imbalance is detected, indicating that current is leaking to earth, the ELCB will quickly trip and disconnect the power supply. This prevents electric shock and potential fires caused by earth faults.

There are two main types of ELCBs: voltage-operated and current-operated. The voltage-operated ELCB was an older design that sensed the voltage between a separate earth wire and the circuit's neutral. If this voltage rose above a certain threshold, it indicated a fault. However, this type was largely superseded by the more common and effective current-operated ELCB, also known as a Residual Current Device (RCD).

Current-operated ELCBs work by comparing the current flowing in the live conductor with the current returning through the neutral conductor. Under normal conditions, these currents are equal. If a fault occurs, such as a person touching a live wire, some current will bypass the neutral and flow to earth. This creates a difference, or residual current, which the ELCB detects. A sensitivity of 30mA is commonly used for personal protection, while higher sensitivities are used for fire protection. ELCBs are crucial components in modern electrical installations for ensuring safety.