SIRIUS S0 frame, 24 VDC — what this contactor is for
The Siemens 3RT2027-1BB44-ZX95 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads and resistive loads in industrial control panels. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, so it drops into any standard panel layout. The 24 VDC coil pulls in at 0.8 of rated voltage and holds reliably across the -25 to +60 °C operating range. Rated switching current at 24 V is 6 A, with a mechanical endurance of 10 million cycles typical — built for high-cycle applications like conveyor lines or pump stations.
Dimensions and wiring — panel fit
At 45 mm wide, 85 mm tall, and 151 mm deep, this S0 contactor fits a standard 45 mm DIN slot. Clearance requirements: 10 mm upwards and forwards, 10 mm downwards, 6 mm at the sides. Main contact wiring accepts solid or stranded 1 to 10 mm² — enough for the 6 A rated current. The coil uses screw-type terminals; auxiliary contact wiring takes 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward — flexible for tight enclosures.
Switching performance and duty cycles
Maximum operating frequency varies by duty: 1000 cycles/hour at AC-1 (resistive), 750 cycles/hour at AC-2 and AC-3 (motor starting/running), and 250 cycles/hour at AC-4 (plugging/inching). DC switching capability: 6 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V. Arcing time is 10 to 10 ms — consistent and predictable for coordination studies. The contactor is rated 5 hp at 230 V for motor applications.