The Siemens 5SV3342-4 is a 4-pole Type B residual current circuit breaker (RCCB) from the SENTRON series, rated at 25 A with 30 mA sensitivity and 400 V AC. Its short-time delayed design means it tolerates brief surge currents — useful on circuits with motor drives or switching power supplies that might otherwise nuisance-trip a standard RCCB.
Type B detection covers AC, pulsating DC, and smooth DC residual currents up to 1 kHz — the right choice where variable-frequency drives, UPS systems, or rectifiers are on the load side. Short-time delayed (S-type) gives you 10 ms immunity to transient leakage, so it coordinates with surge arrestors and doesn't drop the line on every capacitor bank inrush. The 4-pole form factor (3P+N) suits a three-phase four-wire system (TN-S or TN-C-S). Rated supply voltage range is 70–440 V AC at 50/60 Hz, covering standard 400 V three-phase distribution.
Mounting position any, which simplifies layout in crowded panels. IP20 with connected conductors in an installed distribution board; no washdown rating, so keep it inside the enclosure.