What it is and what the ratings mean
The Siemens 5SU1654-0KV32 is a combined residual-current device (RCD) and miniature circuit breaker (MCB) — an FI/LS protector — in a single 1+N-pole module. It integrates type AC residual-current detection (sensitive to sinusoidal AC fault currents) with a B-curve overcurrent trip characteristic rated at 32 A. The 300 mA residual sensitivity (IΔn 300 mA) makes this unit suitable for circuits where a higher trip threshold is needed to avoid nuisance tripping from leakage in equipment or long cable runs — common in distribution sub-mains or circuits feeding multiple loads. The 10 kA breaking capacity (10kA) means it can safely interrupt a fault current up to 10 kA at its rated voltage, which is adequate for most residential and light commercial panelboards where the prospective short-circuit current stays below that level. The B-curve (B 32 A) trips magnetically between 3 and 5 times rated current (96–160 A), so it protects resistive and general-purpose loads without nuisance trips from moderate inrush. The 70 mm depth (D=70mm) is a standard dimension for DIN-rail mounted RCBOs, fitting most enclosures without overhang.
Where it is used
This FI/LS protector snaps onto a 35 mm DIN rail inside a distribution board or sub-panel. It serves as a combined earth-leakage and overcurrent protective device for a final circuit — typically lighting, socket outlets, or small appliance circuits in residential, commercial, or light industrial installations where type AC residual detection is sufficient (i.e., no electronic loads generating pulsed or DC fault currents).
Lifecycle and sourcing
For BOM freeze or maintenance-spares planning, this part is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.