The Siemens SENTRON 5SJ4130-8HG41 is a 1-pole miniature circuit breaker with a D tripping characteristic, rated 30 A at 40 °C and breaking 10 kA per EN 60898.
Mounting and fit
Depth is 70 mm, same as the rail depth, so it sits flush with the backplane. Mounting position is unrestricted: horizontal, vertical, upside-down — the thermal-magnetic mechanism works the same. Terminals accept combined (screw + clamp) top and bottom connections. Tightening torque is 3.5 Nm for copper conductors rated 60/75 °C.
Rated 30 A at 30 °C, 40 °C, and holds 30 A at 45 °C. Above that it derates: 29.1 A at 45 °C, 28.2 A at 50 °C, 27.2 A at 55 °C, 26.4 A at 60 °C. The breaker itself survives -40 to 75 °C ambient, but the trip curve shifts with temperature.