SIRIUS S0 power contactor — what the ratings mean for fit
The Siemens 3RT1025-1AN64 is a SIRIUS S0-frame power contactor, screw-type terminals, designed for switching motor loads in control panels. It mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, with a 45 mm width that fits standard panel density. The 10 A rating at 24 VDC governs the DC coil-holding current; the contactor's main poles carry motor-duty currents defined by the AC-2, AC-4, and AC-12 categories. At AC-2 (400 V) it is rated for 7.5 kW motor switching, while AC-4 at 400 V yields 15.5 A for reversing or inching duty. The AC-12 maximum operating current of 10 A covers resistive loads on the auxiliary contacts. Fuse coordination is specified: Type 2 coordination requires a gL/gG 25 A fuse; Type 1 coordination allows a gL/gG 63 A fuse. This lets the panel builder size the branch protection to match the required fault-clearing performance.
Integration — panel fit and wiring
Dimensions: 85 mm height, 45 mm width, 140 mm depth. The S0 frame leaves 6 mm side clearance for side-by-side mounting. Front protection is IP20; terminal area is IP00 — suitable for enclosed panels, not open washdown zones. Screw terminals accept solid or stranded conductors: main contacts handle 2x (1–2.5 mm²), 2x (2.5–6 mm²), max 2x 10 mm²; auxiliary/coil terminals accept 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), max 2x (0.75–4 mm²). AWG equivalents for main contacts: 2x (16–12), 2x (14–10), 1x 8. Operating temperature range is -25 to +60 °C, with a maximum altitude of 2000 m. Pollution degree 3 means it tolerates conductive pollution in industrial environments.
Coil voltage and auxiliary contact configuration
The coil operates at 50/60 Hz with rated voltage ranges: 200 V at 50 Hz, 200–220 V at 60 Hz. The voltage tolerance band is 0.8–1.1 at 50 Hz and 0.85–1.1 at 60 Hz. Two instantaneous auxiliary contacts are built in. Auxiliary contact switching capacity at various voltages: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V. Mechanical endurance is 10,000,000 operations typical.