It's rated 40 A, 30 mA sensitivity, Type A-SI (Super Immunised), meaning it handles pulsed DC faults and resists nuisance tripping from high-frequency harmonics on motor drives or UPS supplies. The 3P+N pole configuration with neutral on the left suits 3-phase group incomer duty at 400 V AC 50/60 Hz.
The 40 A [In] and 30 mA IΔn are the two numbers that decide whether this RCD fits your distribution board. 40 A is the thermal continuous current — it matches a 40 A MCB upstream. The 30 mA sensitivity provides personal protection against direct contact, within the limits of IEC 60364. Type A-SI (Super Immunised) adds a layer of immunity to pulsed DC and high-frequency AC leakage, which is common on VFD-fed loads or electronic ballasts. Voltage-independent tripping means the device operates without needing a neutral-to-earth voltage — it uses the fault current itself to trip, so it works even if the neutral is lost upstream.
Clip-on mounting to DIN rail, 6 modules wide (108 mm). Designed as a group incomer, it sits at the head of a sub-distribution board, bolted by screws to the adjacent MCB. Tunnel terminals accept 1–16 mm² rigid or 1–10 mm² flexible cable; tighten to 2 N·m. IP20 body, IP40 in a modular enclosure. Pollution degree 3 per EN/IEC 61009-2-1 — suitable for industrial panels where conductive dust is present.