What this RCBO is and what the ratings mean
The Siemens 5SU1654-7RC10 is a 2-pole RCBO (Residual Current Breaker with Overcurrent) rated 10 A with C characteristic, Type A sensitivity at 300 mA, packed into a 2-module width. The C characteristic means the magnetic trip curve operates at 5 to 10 times rated current — so a 10 A unit holds through motor inrush and capacitive loads that would nuisance-trip a B curve, but clears faster than a D curve for general branch-circuit protection. Type A residual protection detects both sinusoidal AC fault currents and pulsating DC fault currents up to 6 mA smooth DC, which covers most modern electronics and VFD-fed loads. The 300 mA sensitivity is a fire-protection threshold, not a personnel-protection one (that would be 30 mA or lower); it's typically specified for distribution sub-mains, lighting circuits, or equipment where nuisance tripping on leakage from filters and drives must be balanced against ground-fault detection.
Integration into a panel
The 2-module width (about 36 mm on a standard DIN rail) fits a standard distribution board or sub-distribution enclosure. The 2-pole form factor switches both line and neutral, which is required for TN-S and TT systems where the neutral is not solidly bonded at the board. Spring-cage or screw terminals accept 1.5 to 25 mm² conductors depending on the terminal design — verify the maximum conductor size on the unit's label before terminating paralleled feeds.