Its primary job is detecting earth leakage currents and disconnecting the circuit to protect against electric shock and fire. The short-time delayed feature (also called selective or S-type) introduces a deliberate trip delay, enabling full selectivity with downstream RCCBs so that a fault on a sub-circuit clears without knocking the main board offline. The 25 A continuous rating is thermally derated above 45 °C: the part holds 25 A up to 45 °C, then drops to 23.5 A at 50 °C, 22 A at 55 °C, 20.5 A at 60 °C, 19 A at 65 °C, and 17.5 A at 70 °C. The 3 kA surge current resistance (I_m) covers the impulse withstand capability — important for installations exposed to lightning-induced surges. The I²t let-through is rated at 70 000 A²·s, and the permissible switching function is short-term delayed, which aligns with selective coordination requirements in IEC 60364. The protection against electric shock is finger and back-of-hand safe (IP2X equivalent), and the enclosure achieves IP20 only when the distribution board is installed with connected conductors — not a standalone outdoor rating.
Mounts on DIN rail (REG) in any position. Supply can be fed from top or bottom.