Siemens SENTRON 5SU1654-7KK40 — RCBO, 40 A, Type A, 300 mA
The Siemens SENTRON 5SU1654-7KK40 is a 1P+N RCBO (residual current operated circuit breaker with overcurrent protection) rated 40 A at 230/240 V AC, 50 Hz, with a C tripping characteristic and Type A residual current sensitivity at 300 mA. Type A residual current detection handles pulsating DC fault currents — common on single-phase rectified loads (SMPS, LED drivers, VFD front-ends) — which a standard AC type would miss. IP20 applies once installed with conductors connected — the board enclosure provides the actual ingress protection.
Panel fit and mechanical data
Comparison with 5SU9354-7KK16
The closest functional peer is the 5SU9354-7KK16, also a 1P+N SENTRON RCBO with the same mechanical footprint (36×90×77 mm), same C-curve, and same halogen-free/silicon-free construction. The deciding difference: the 5SU1654-7KK40 carries a 15 kA breaking capacity per IEC 60947-2 versus 10 kA on the 5SU9354-7KK16, and its Type A residual current threshold is 300 mA (not 30 mA). The 5SU1654-7KK40 also has a lower minimum test voltage (100 V vs 195 V). If your coordination study requires 15 kA at the device or a 300 mA trip threshold, the 5SU1654-7KK40 is the correct BOM line; otherwise the 5SU9354-7KK16 is a drop-in alternative on the same panel cutout.