The Siemens 5SU1354-7FM20 is a 1-pole-plus-neutral RCBO (residual current circuit breaker with overcurrent protection) rated for 20 A at 230 V AC with a 10 kA breaking capacity. It combines a type A residual current device (30 mA trip threshold) with a C-characteristic MCB in a single DIN-rail module — one unit covers both earth-leakage and overload/short-circuit protection for a final subcircuit.
What the ratings mean for fit
The 10 kA breaking capacity (Icn) tells you this RCBO can safely interrupt fault currents up to that level at 230 V AC — adequate for most domestic and light-commercial distribution boards where the prospective short-circuit current at the outgoing terminals stays under 10 kA. The C-characteristic (C-Char) means the magnetic trip operates at 5–10× In (100–200 A for this 20 A unit), so it tolerates motor inrush and capacitive loads without nuisance tripping while still clearing hard faults quickly. Type A residual current detection handles pulsating DC fault currents (rectified waveforms from electronics, variable-speed drives, LED drivers) in addition to sinusoidal AC — essential for modern circuits where non-linear loads are present. The 30 mA sensitivity is the standard for personal protection against direct contact (IEC 60364).
Sourcing and lifecycle
For a BOM line or panel build, this part is sourced to order against an RFQ. Availability and current pricing are confirmed at quote time through our supply network.