The Siemens 5SM1652-6 is a SENTRON 4-pole residual current circuit breaker (RCCB), Type A, rated 25 A with a 300 mA residual trip threshold at 500 V AC. It's an instantaneous design — no intentional short-time delay on the trip — so it responds to earth faults immediately. Type A detection covers sinusoidal AC and pulsating DC fault currents, which is the standard pick for circuits feeding electronics, VFDs, or single-phase rectifiers where pure AC-only (Type AC) RCCBs might miss a pulsating DC component.
Thermal derating and panel fit
Rated 25 A at 40 °C and 45 °C ambient. Above that the derating curve is published: 24 A at 50 °C, 23 A at 55 °C, 22 A at 60 °C, 21 A at 65 °C, and 20 A at 70 °C. If the enclosure runs hot — say a crowded DIN rail with contactors and breakers — factor the actual ambient, not the nameplate 25 A. The 4-pole body takes 4 width units (about 72 mm on a standard DIN rail). Minimum storage temperature is -40 °C, operating minimum -25 °C; maximum storage 60 °C, operating max 45 °C. Mounting position is unrestricted. IP20 with connected conductors in an installed distribution board — fine inside a closed panel, not for wet-area standalone use.
SCCR and overvoltage category
Short-circuit current rating is 10 kA. Overvoltage category III — suitable for fixed installation downstream of the service entrance, not just socket-outlet circuits. Surge current withstand is 1 kA. Supply connection can land top or bottom. A test-circuit supply minimum of 100 V AC is needed to exercise the test button.