It adds earth leakage protection to the circuit, with a rated residual sensitivity of 300 mA and a Type A-SI (Super Immunised) characteristic — meaning it handles pulsed DC earth faults and is immune to nuisance tripping from high-frequency harmonics or transient surges common on modern electronic loads.
Rated at 63 A (In) and 230…415 V AC (Ue), this 2-pole block is sized for the outgoing feeder of a single-phase or three-phase sub-distribution board. The selective (time-delayed) earth-leakage protection means it coordinates with downstream RCDs — it will hold during a momentary fault on a branch circuit, letting the downstream device clear first, then trip if the fault persists. This avoids a full-board blackout for a single branch fault. The voltage-independent residual current tripping technology means the RCD operates without needing a separate power supply; it uses the fault current itself to trigger the mechanism. This is a reliability advantage in installations where the neutral could be lost upstream.
The bottom tunnel terminals accept 1…35 mm² rigid or 1…25 mm² flexible cable, with a tightening torque of 3.5 N·m. The 14 mm strip length is standard for this terminal class. A comb busbar can feed the bottom terminals, simplifying multi-pole distribution.
Designed and certified to EN/IEC 61009-1 and EN/IEC 61009-2-1 (the RCD/MCB combination standards). Rated insulation voltage (Ui) 500 V AC, impulse withstand (Uimp) 6 kV. The 8/20 µs impulse withstand of 3000 A confirms it survives lightning-induced surge currents without damage.