What is a common application of RCDs in residential homes?

Residual Current Devices (RCDs) are safety devices used in electrical systems to protect against earth faults, specifically by detecting imbalances in electrical current. In residential settings, they play a crucial role in preventing electric shock and reducing the risk of electrical fires caused by faulty wiring or appliances.

When a person comes into contact with a live conductor, current may flow through their body to the ground, creating an imbalance between the current flowing in the live wire and that returning via the neutral wire. An RCD monitors this current flow and, if it detects a difference (indicative of leakage to earth), it quickly disconnects the power supply, minimizing the risk of serious injury or damage.

This application is particularly important in areas of the home where water is present, such as bathrooms and kitchens, thus ensuring a higher level of safety for occupants. The other options relate to functions that RCDs do not perform, as they do not convert current types, limit current flow, or enhance circuit capacity.