The Siemens SENTRON 5SU1353-7KK25 is a 1P+N RCBO (residual current circuit breaker with overcurrent protection) rated 25 A at 30 °C with a Type C tripping characteristic. It breaks faults at 4.5 kA per EN 60898 and 15 kA per IEC 60947-2, so it handles both the domestic-standard and industrial-standard short-circuit ratings in one unit — the 15 kA figure is the one that matters for industrial panel coordination.
Ratings and derating
The 25 A rating at 30 °C drops to 18.25 A at 70 °C — a 27 % derating. If the panel ambient runs hot (say 50 °C), the usable current is 21.75 A, so size the load accordingly. The insulation voltage is rated 264 V, overvoltage category III, pollution degree 2, which is standard for fixed-installation distribution boards. Operating frequency is 50 Hz only — not 50/60 Hz dual-rated. If the installation is on a 60 Hz supply, this part does not apply.
Mounting and integration
Two modular width units (36 mm wide) snap onto DIN rail. Depth is 77 mm, installation depth 70 mm. Mounting position is any, so it fits vertical or horizontal busbar arrangements. Supply can enter from top or bottom. IP20 with connected conductors in a distribution board — standard for enclosed panel use, not for wet areas.