SIRIUS S0 contactor — AC-12, AC-2, AC-4 duty
The Siemens 3RT1025-1AN60 is a SIRIUS-brand power contactor in the S0 frame size, designed for screw and snap-on mounting onto 35 mm standard mounting rail per DIN EN 50022. It carries a maximum operating current of 10 A in AC-12 duty, and at AC-2 at 400 V it is rated for 7.5 kW motor switching. For AC-4 reversing or inching duty at 400 V, the rated operating current is 15.5 A — the higher current reflects the resistive/inductive load mix in that category. The contactor measures 45 mm wide by 85 mm high by 91 mm deep, fitting into a standard 45 mm DIN-rail slot. Front-face protection is IP20; the terminal area is rated IP00, meaning the wiring compartment is open to the panel environment — expect to maintain clearance around live parts.
Coordination and protection
For Type 2 coordination (no damage to the contactor after a short-circuit fault), the required upstream fuse is gL/gG 25 A. For Type 1 coordination (contactor may need replacement after fault), the fuse can be gL/gG 63 A. The main circuit uses screw-type terminals accepting 2x (1 to 2.5 mm²) stranded or 2x (2.5 to 6 mm²) solid, with a maximum of 2x 10 mm². The auxiliary circuit accepts 2x (0.5 to 1.5 mm²) solid, 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²). AWG equivalents for main contacts are 2x (16 to 12), 2x (14 to 10), or 1x 8. Ambient operating temperature range is -25 to +60 °C, and the device is rated for pollution degree 3 (industrial environment with conductive or dry non-conductive pollution). Maximum operating altitude is 2 000 m.