The Siemens 5SM2632-0 is a SENTRON residual-current device (RCD) unit designed to snap onto the same DIN rail as the 5SY miniature circuit breakers, forming a combined RCBO-type protection block in a 3-module-width footprint. The design is instantaneous (no time delay), so it trips as soon as the fault current exceeds the threshold.
At 40 °C ambient it is rated at 37.2 A, and at 45 °C it holds at 37.2 A; derate further to 36 A at 50 °C, 34.8 A at 55 °C, 34 A at 60 °C, 33.2 A at 65 °C, and 32 A at 70 °C. The 300 mA residual trip threshold is typical for fire-protection or equipment-protection applications rather than personnel protection (which usually calls for 30 mA or lower).
The 5SM2632-0 carries the SENTRON brand and is designed for use in residential and commercial distribution boards. It is rated for 50 Hz supply frequency only. The insulation voltage (Ui) is rated at 460 V, and surge voltage resistance is 4 000 V. The unit includes protection against false tripping.