The Siemens 3RT2325-1BM40 is a SIRIUS contactor in size S0, with a 24 VDC magnet coil terminated via screw-type terminals. At its rated coil voltage of 24 VDC, the main contacts carry 10 A. The contactor is rated for DC switching at several voltage levels: 10 A at 24 V, 6 A at 60 V, 2 A at 48 V, 1 A at 110 V, and 0.3 A at 220 V — so the load current drops sharply as voltage rises, which is typical for DC contactors. The coil pulls in at 0.8 × rated voltage and drops out at 1.1 × rated voltage, with an arcing time of 10 ms.
The contactor accepts solid conductors of 2 × (0.5 … 1.5 mm²) and 2 × (0.75 … 2.5 mm²) on the auxiliary contacts, and stranded wire up to 10 mm² on the main terminals. The screw-type coil terminals use the same wire ranges.