It provides earth leakage protection for a 3-pole (3P) circuit rated at 25 A, with a 30 mA sensitivity and Type AC detection for sinusoidal AC fault currents.
The 30 mA sensitivity is the standard threshold for personal protection against indirect contact in residential and commercial final circuits — it's the trip level that catches leakage through a human body while avoiding nuisance trips from normal cable capacitance. The 25 A rated current matches the upstream MCB rating; this add-on block is sized to the same thermal capacity as the breaker it pairs with.
This is an add-on block that mounts via clip-on to a DIN rail and screws directly to the underside of an iC60 MCB. It occupies 6 x 9 mm pitches — 54 mm width — so it takes three standard modular positions on the rail. The tunnel-type terminals on the bottom accept 1...25 mm² rigid cable or 1...16 mm² flexible with or without ferrules, with a 2 N·m tightening torque and 14 mm strip length. The IP20 enclosure is standard for enclosed distribution boards; IP40 when installed in a modular enclosure.