RCCB for 400 V four-wire systems — Type A, 25 A, 300 mA
The Siemens SENTRON 5SM3642-6BA is a 4-pole RCCB rated 25 A at 400 V AC, 50 Hz, with a 300 mA tripping residual current. It is a Type A device. Its instantaneous design trips within milliseconds of a residual fault. The 10 kA SCCR allows safe interruption of faults up to 10 kA.
Wire termination and panel fit
Tightening torque is 2.5 to 3 N·m, typical for screw-type RCCB terminals; a torque screwdriver is recommended to avoid terminal heating. Installation depth is 70 mm, matching standard DIN-rail enclosures. IP20 protection applies once the distribution board is installed and conductors are connected — the device itself is finger-and-back-of-hand safe (touch-proof) per the overvoltage category III rating.