Siemens 5SU1154-6KV16 FI/LS Protector Type A, B 16A, 10kA, 1

The Siemens 5SU1154-6KV16 is a combined residual-current device and miniature circuit breaker (RCBO) — one module that does both jobs in a single 70 mm-wide DIN-rail housing. The 10 mA rated residual current (IΔn) is the sensitive end of the Type A detection range — it catches sinusoidal AC faults and pulsating DC faults, including those from single-phase rectifiers in electronics. That sensitivity makes it suitable for circuits supplying IT equipment, medical devices in Group 1 rooms (per IEC 60364-7-710), or wet-area socket outlets where 30 mA would be too coarse. The 1+N-pole form factor switches the line conductor only; the neutral is switched but not protected against overcurrent — standard for TN-S and TN-C-S systems where the neutral is solidly grounded.