What the ratings mean for your panel
The 5SV3745-6KK01: The 125 A rated current (In) sets the continuous load capacity — sized for a main distribution board or submain feeding multiple branch circuits up to that ampacity. The 500 mA residual sensitivity (IΔn) is higher than the standard 30 mA personal-protection threshold; this is a fire-protection or equipment-protection device, not a shock-hazard guard. Type A detection covers sinusoidal AC residual currents and pulsating DC residual currents up to 6 mA, covering most electronic loads (VFDs, switching power supplies, UPS rectifiers) that generate pulsed DC leakage. The short-time delayed characteristic means the RCCB will not trip on short-duration leakage spikes up to several hundred milliseconds — a deliberate choice for circuits where nuisance tripping on transient inrush (e.g., capacitor banks, motor starting) must be avoided.
Deployment context
This is a DIN-rail mounted RCCB for installation inside a distribution panel or enclosure. The 4-pole format (3 phases + neutral) suits three-phase systems with a solidly grounded neutral, common in European and Asian industrial and commercial installations. The 500 mA trip level and short-time delay make it appropriate for a submain ahead of multiple branch RCCBs or as a main switch with residual protection in a panel feeding equipment that generates background leakage. The packaging dimensions (78 x 97 x 85 mm) give the panel-builder the footprint for DIN-rail spacing and enclosure fill calculations.
Sourcing is straightforward: the 5SV3745-6KK01 is quoted and ordered against an RFQ through independent distribution, with current pricing and availability confirmed at quote time. For a BOM line that requires this exact order code — 125 A, 500 mA, Type A, short-time delayed — there is no parametric substitute that matches all four constraints; the fit is determined by the combination of ampacity, sensitivity, waveform type, and time characteristic. A buyer holding an obsolete 4-pole RCCB at a lower amp rating or different sensitivity should verify the panel's existing leakage profile before substituting this higher-current unit.