The Siemens SENTRON 5SV4342-0MB is a 4-pole residual current circuit breaker (RCCB) rated for 25 A at 40 °C with a 30 mA trip threshold, Type AC, for 400 V AC 60 Hz systems.
The 30 mA residual trip is the standard threshold for personnel protection against electric shock in most IEC-based installations. Rated current holds at 25 A from 40 °C through 60 °C ambient, then derates to 23.3 A at 65 °C and 17.6 A at 70 °C. In a warm panel (say 55 °C), the full 25 A is available; above 60 °C you lose headroom. The 10 kA SCCR (IEC 61008-1) means the device withstands a 10 kA prospective fault current — common for a sub-distribution board downstream of a larger main breaker. Let-through energy (I²t) is rated at 58 000 A²·s, with a permissible let-through current of 5 200 A. This tells the downstream cable and busbar sizing engineer what energy the RCCB passes during a fault — useful for verifying that the connected wiring and terminals are rated for the stress.
Depth is 70 mm.