Residual current circuit breakers are used to detect and protect against fault currents. They ensure fault protection, additional protection (personal protection), and protection against electrically ignited fires caused by fault currents to ground. The FN series residual current circuit breakers in the AEG portfolio are primarily used in residential and commercial applications. Combined with a comprehensive range of accessories, the portfolio provides everything you need for your installation tasks. RCD types A, AI, AS, B, and F. Rated currents from 25 A to 100 A and rated fault currents up to 500 mA (30, 300, 500 mA). Type B RCDs are suitable for non-linear circuits that can generate fault currents with a high DC component (> 6 mA) or AC fault currents with various frequencies.