It protects a single-phase final subcircuit (1P+N, neutral switched) against overload, short-circuit, and earth leakage. The C-curve trip characteristic means it holds 5–10× rated current momentarily, so it's the standard choice for motor-starter and general-purpose loads that draw a moderate inrush without nuisance tripping.
Thermal derating matters here
At 40 °C it derates to 23.5 A, at 50 °C to 21.75 A, and at 70 °C to 18.25 A.
Breaking capacity — two standards, two numbers
Rated short-circuit breaking capacity is 4.5 kA per EN 60898 (the household-standard test) and 15 kA per IEC 60947-2 (the industrial-standard test). The higher IEC figure applies when the device is installed in an industrial distribution board with a higher prospective fault current — that's the number the panel designer needs for the SCCR label.
Integration notes
Two modular-width units (36 mm) snap onto standard DIN rail. Depth is 77 mm, installation depth 70 mm — check gland-plate clearance before wiring. IP20 rating applies only with the distribution board closed and conductors connected; open-door work requires a lockout.