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. It carries a 10 kA breaking capacity per EN 60898 and 15 kA per IEC 60947-2, covering both domestic and industrial coordination requirements. The C-curve means the magnetic trip operates at 5 to 10 times In (200–400 A), suited for inductive loads like small motors or fluorescent lighting banks where inrush could nuisance-trip a B-curve device. 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. Mounts on a standard DIN rail in a distribution board; the 2 MW width (36 mm) occupies two 18 mm modular slots. IP20 applies once installed with conductors connected — the board enclosure provides the actual ingress protection.
Panel fit and mechanical data
Dimensions: 36 mm wide, 90 mm high, 77 mm deep, with an installation depth of 70 mm behind the panel face. The supply cord can enter from either top or bottom, and the device can be mounted in any orientation. Halogen-free and silicon-free construction matters for clean-room or high-reliability environments where outgassing could contaminate contacts or optics.
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.