The Siemens 5SU1656-6KV32 is a combined residual-current device and miniature circuit breaker (RCBO) — an FI/LS protector in Siemens' 5SU1 series. It packs Type A earth-leakage detection (300 mA rated residual current) and a B-curve overcurrent trip (32 A) into a single 70 mm-wide, 1+N-pole module.
The 300 mA sensitivity is a fire-protection level, not personnel protection (30 mA is the touch-safe threshold). Use this where the earth-leakage alarm threshold is set above equipment leakage but below cable-insulation damage risk. The B-curve trips magnetically at 3–5× In (96–160 A for this 32 A unit), so it clears fast on short circuits but tolerates the inrush of resistive and modest motor loads. At 70 mm wide (roughly 4 modular spaces on DIN rail), this RCBO replaces a separate RCD and MCB in the same enclosure footprint. The 1+N-pole configuration switches both line and neutral, which is standard for single-phase final circuits in many European and Asian markets.
No direct cross-reference or second-source equivalent is recorded on this line; the Siemens 5SU1 family shares the same mechanical footprint and terminal layout across the range, so a parametric substitute (different rating or curve) would mount identically on the DIN rail.