The Siemens SENTRON 5SM1654-6 is a 4-pole residual current circuit breaker (RCCB) in the 5SM1 design, rated 40 A at 500 V AC with 300 mA trip sensitivity and Type A fault-current recognition. The 300 mA sensitivity is a fire-protection level, not a personnel-protection level (that would be 30 mA or lower), so it's sized for the main incoming supply or sub-distribution where the goal is equipment and cable protection rather than shock protection. The I²t value of 70 000 A²·s is the let-through energy it can withstand; pair it with a breaker whose let-through stays under that curve. The derating curve is published: full 40 A up to 45 °C, then 38.4 A at 50 °C, 36.8 A at 55 °C, stepping down to 32 A at 70 °C. Instantaneous tripping characteristic (no intentional short-time delay) means it clears ground faults immediately — no coordination window for selective tripping downstream. If you need time-graded selectivity between RCCBs on the same feeder, look at the S-type or K-type delayed variants instead.
Panel and mounting
IP20 with connected conductors and distribution board installed; finger-safe and back-of-hand-safe terminals.