Summary

A leakage protector (RCD), also known as a residual current switch (LDS) or leakage circuit breaker, is primarily used to protect against potentially fatal electric shock and equipment leakage. It provides overload and short-circuit protection, protecting lines or loads from overload and short circuits. It can also be used to infrequently switch circuits under normal circumstances.

There are many types of RCDs currently available on the market, but their principles generally differ. A RCD consists of three main components: a detection element, an intermediate amplification stage, and an actuator.
1. Detection element: This consists of a current transformer that detects leakage current and generates a signal.
2. Amplification stage: This amplifies the weak leakage signal and can be mechanical or electronic, depending on the device.
3. Actuator: Upon receiving the signal, the thyristor switches from the off state to the on state. When the main coil is energized, the main switch switches from the closed state to the open state, thereby shutting off the power supply.