The Schneider Electric A9DF3725 is an Acti9 iCV40 residual-current circuit breaker with overcurrent protection (RCBO) — a single module that combines a 25 A thermal-magnetic MCB with a 30 mA earth-leakage detector in a 3P+N, 4-module-wide package.
The 3P+N unit occupies 10 × 9 mm pitches (90 mm width) on a DIN rail, with a depth of 73 mm and height of 93 mm. The neutral is on the left; the connection pitch is 18 mm between phases and 9 mm between phase and neutral — standard for Acti9 modular enclosures. Tunnel terminals accept 1–16 mm² rigid or 1–10 mm² flexible cable; strip length is 14 mm, torque to 2 N·m.
For a BOM freeze or a line-down replacement, the spec is fixed: 25 A rated current, 30 mA earth-leakage sensitivity, C-curve, 3P+N, 6 kA at 400 V AC. No second-source cross-reference exists within the Acti9 family at this exact rating combination — the iCV40N (device short name) is the only variant with these parameters.
Durability and environmental limits
Rated for 20,000 electrical and 20,000 mechanical cycles — consistent with a distribution-grade RCBO for frequent switching under load. Operating altitude is 2000 m; relative humidity tolerance is 95% at 55 °C, which covers most non-condensing indoor environments.