This is the part you spec when you need time-delayed tripping for selectivity downstream of a main RCD — it lets a fault clear on the branch without dropping the whole distribution board.
Selectivity and trip coordination
The selective design (S-type) means this RCCB withstands transient earth faults and inrush without tripping, so a downstream RCCB clears the fault first. Rated residual current is 300 mA — not the 30 mA you'd use for personal protection. That 300 mA threshold plus the intentional delay is what buys you coordination in a multi-level distribution panel.
Temperature derating and installation
That's unusual for a 40 A device and simplifies BOM validation. IP20 applies once the distribution board is installed and conductors are connected; treat it as a panel-internal device, not a field-mounted enclosure. Silicon-free construction is noted for environments where outgassing contaminates sensitive contacts or optics.