The Schneider Electric A9N16261 is a 4-pole residual current circuit breaker (RCCB) from the Acti9 xID range, rated at 80 A with 30 mA earth-leakage sensitivity — the standard threshold for personal protection against direct contact in residential and commercial final circuits. That makes it suitable for general-purpose circuits feeding resistive, inductive, or lighting loads where no rectified or pulsed DC fault currents are expected.
Clip-on mounting onto a DIN rail, 18 mm phase-to-phase pitch, occupying 8 x 9 mm pitches — so 72 mm wide on the rail. Neutral on the left, tunnel terminals top and bottom accepting 1...35 mm² rigid or 1...25 mm² flexible, with a 3.5 N·m tightening torque and 14 mm strip length. The IP20 finger-safe terminals are fine for enclosed distribution boards; no washdown rating here, so keep it behind a gland plate or panel door. Padlocking provision for lockout/tagout on the toggle, with local ON/OFF/fault-trip indication on the face.
80 A rated current (In) governs the continuous load the RCCB can carry without tripping on thermal overload — sized for a 3-phase submain or a large single-phase final circuit. The 30 mA sensitivity is the IEC-recommended touch-protection threshold; it will trip on any earth fault exceeding that residual current, typically within 300 ms (instantaneous, no intentional delay). The 4000-cycle electrical and mechanical durability is standard for a switch-disconnect device in normal duty; not a high-endurance figure for frequent switching, but adequate for protection duty where the device operates only on fault or during testing.