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 6 kA breaking capacity covers residential and light commercial final circuits where the prospective fault current stays under that threshold.
What the ratings mean for fit
Type A detection means it responds to AC residual currents and pulsating DC fault currents — the minimum for circuits with single-phase rectified loads (washing machines, LED drivers, EV chargers). 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. The 6 kA rated short-circuit capacity (Icn) is adequate for TN and TT systems at the sub-distribution level; verify the prospective fault current at the installation point does not exceed 6 kA. 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.
Sourcing and lifecycle
For BOM-line planning, this part is sourced to order against an RFQ. Availability and current pricing are confirmed at quote time through independent distribution. 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.