The Siemens SENTRON 5SV5342-6 is a 4-pole residual current operated circuit breaker (RCCB), Type A, rated 25 A with a 30 mA trip threshold for AC 400 V residential and commercial branch circuits. It's an instantaneous-trip device (no short-time delay), so it clears ground faults within one cycle — no coordination with delayed RCCBs downstream. IP20 with connected conductors in an installed distribution board — fine for enclosed panels, not for wet or dust-laden environments without an outer enclosure.
Fault ratings and selectivity
Short-circuit current rating is 6 kA per IEC 61008-1, with a conditional rating of 0.8 kA under that standard. The series fuse maximum permissible is 80 A, so if upstream protection is larger, the RCCB may not be fully coordinated under fault. Power dissipation is 2.6 W per pole in hot operating state at rated current — 10.4 W total for the 4-pole unit. That's modest, but in a tightly packed DIN-rail enclosure with multiple RCCBs, the cumulative heat can raise ambient above the 45 °C maximum. Keep ventilation paths clear.
Installation constraints
Installation depth is 70 mm, matching the unit depth. Grid spacing of 60 mm is standard for modular DIN-rail components. Silicon-free construction matters for automotive paint-shop or semiconductor fab installs where silicone outgassing causes adhesion or contamination issues. Overvoltage category III means it's rated for fixed-installation distribution level, not for downstream socket outlets.