The Siemens 5SM3347-4KK14 is a SENTRON residual current operated circuit breaker (RCCB), 4-pole, rated 80 A with a 30 mA residual trip threshold, Type B+, short-time delayed. It is designed for 400 V AC, 50/60 Hz systems and carries a 10 kA short-circuit current rating per IEC 61008-1 and EN 60898. Type B+ means it detects AC, pulsating DC, smooth DC, and high-frequency AC residual currents — the full spectrum you get from VFDs, UPS systems, and rectified loads. The short-time delayed characteristic (S-type) prevents nuisance tripping from transient leakage pulses common on industrial lines with long cable runs or switching supplies.
Mounting position is any; supply can enter from top or bottom — bottom feed keeps the SIGRES function live even with the switch off. IP20 with conductors connected, so it lives inside a distribution board or enclosure, not exposed to washdown.
Electrical and environmental ratings
Rated for overvoltage category III, ambient range -25 °C to 45 °C operating, storage down to -40 °C. The test circuit requires a minimum supply voltage of 195 V to function.