What are RCDs, and why are they used?

Residual Current Devices (RCDs) are crucial safety devices designed to protect individuals from electric shock and prevent electrical fires. They work by detecting imbalances in electrical currents, which occur when current flows through an unintended path, such as a person who may accidentally touch a live wire. When an imbalance is detected, the RCD quickly disconnects the electrical supply, significantly reducing the risk of severe injury or fatality from electric shock.

The use of RCDs is particularly important in environments where electrical devices may come into contact with water, such as kitchens and bathrooms, enhancing overall electrical safety. They are mandated in many electrical installations to comply with safety regulations, reflecting their critical role in safeguarding people from the dangers associated with electrical faults.

The other options represent different functionalities that do not align with the primary purpose of RCDs. Devices for monitoring energy efficiency, components for enhancing the performance of electric motors, and devices that regulate power supply do not serve the protective function against electric shock, which is the essential characteristic that defines RCDs.