The Type B+ classification means it detects smooth DC residual currents (up to 6 mA DC) plus AC and pulsed DC — essential on drives, UPS feeds, or any line with rectifier loads where a standard Type A would miss a fault. The short-time delayed characteristic (short-term delayed per the design) gives it a deliberate trip delay, so it coordinates downstream with instantaneous devices and avoids nuisance tripping on inrush or surge currents up to 3 kA surge current resistance.
Snaps onto DIN rail (REG rail per the spec), occupies 4 modular width units (4 MW at 18 mm each — 72 mm total width). Mounting position is any, so vertical or horizontal in the enclosure is fine. Depth is 70 mm — fits standard 100 mm deep distribution boards with room for gland plates. Supply can enter from top or bottom; the SIGRES function (test circuit) stays live from the top even when the RCCB is switched off, which matters for remote test scenarios. IP20 applies only when the distribution board is installed and conductors are connected — not for open-panel use.