Part identity and function
The Siemens 5SU1654-7RC06 is a combined residual-current circuit breaker with overcurrent protection (RCBO) rated at 6 A, 2-pole, in a 2-module width. It carries a C characteristic for moderate inrush tolerance and a Type A residual-current sensitivity of 300 mA.
What the ratings mean for fit
The 6 A rating with C-curve tripping characteristic suits circuits with moderate inrush — think small motor loads, lighting banks, or control transformers — where the magnetic trip must ride through the start surge without nuisance opening. The Type A, 300 mA residual sensitivity detects pulsating DC fault currents (typical from rectified loads) plus standard AC, while the 300 mA threshold is sized for fire protection rather than personal shock protection (30 mA is the touch-safe level). Two-module width means it occupies two 18 mm DIN-rail spaces in a consumer unit or distribution board.
Deployment context
Snap-on DIN-rail mounting for panel or enclosure integration. The 2-pole format (switched line and neutral) is standard for single-phase final circuits where the neutral is switched and protected.