This is a Type A RCCB, meaning it responds to sinusoidal AC residual currents as well as pulsating DC residual currents — common in modern equipment with rectifiers, switching power supplies, and variable-speed drives. The instantaneous design means it trips without intentional delay when the residual current exceeds the 300 mA threshold.
The 40 A rated current (In) and 400 V AC rated voltage define the continuous load the RCCB can carry on a 3-phase+N system. The IP20 rating applies once the distribution board cover is installed and conductors are connected — standard for enclosed panel use. Terminal capacity accepts conductors from 1.5 mm² up to 25 mm², covering most branch-circuit wiring sizes.