Siemens SIRIUS 3RT1025-1XF00-0GA0 — S0 Power Contactor with Integrated Varistor
The Siemens SIRIUS 3RT1025-1XF00-0GA0 is a power contactor in the S0 frame size, designed for screw and snap-on mounting onto a 35 mm standard mounting rail per DIN EN 50022. It carries a built-in varistor for surge suppression, saving a separate suppressor module and one wiring step in the panel. The contactor is rated for AC-2 duty at 7.5 kW and AC-4 duty at 15.5 A, both at 400 V, making it suited for reversing or plugging motor loads where frequent switching under load is expected. The main contact circuit uses screw-type terminals, accepting 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), or max. 2x (0.75...4 mm²) solid conductors, with AWG equivalents of 2x (16...12), 2x (14...10), or 1x 8. The auxiliary contact block is rated for switching at multiple control voltages: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, and 3 A at 400 V — covering common control-circuit levels across global panels.
Duty Ratings and Coordination
The 3RT1025-1XF00-0GA0 is rated for motor loads up to 10 kW at 500 V and 11 kW at 690 V, which covers 400 V class motors with headroom for voltage drop or longer cable runs. The AC-4 rating of 15.5 A at 400 V is the figure to watch for inching or jogging applications — that's the current the contactor can interrupt under the harsher switching conditions of starting against a rotating load. For type 2 coordination (no-weld requirement), the recommended upstream fuse is gL/gG 25 A; for type 1 coordination (welding allowed but no fire risk), a 63 A gL/gG fuse is permitted. The contactor is rated for side-by-side mounting without derating, which simplifies multi-contactor panels. The operating temperature range of -25 to +60 °C covers most indoor industrial environments, and the maximum operating altitude of 2,000 m is standard for non-derated installations.
Panel Integration Notes
The S0 frame measures 45 mm wide, 116 mm high, and 101 mm deep — a standard footprint that fits alongside other SIRIUS S0 devices on a 35 mm DIN rail. The front face carries IP20 protection (finger-safe), while the terminal area is rated IP00, so the contactor must be mounted inside an enclosure that provides the required system IP rating. The built-in varistor eliminates the need for a separate surge suppressor module, saving one DIN-rail position and reducing wiring complexity. The terminal blocks accept solid conductors up to 4 mm² (main contacts) and 2.5 mm² (auxiliary), with a strip length that matches standard screw-terminal practice. For AWG users, the main contacts accept 2x 16–12 AWG or 1x 8 AWG. The pollution degree rating of 3 means the contactor is suitable for industrial environments with conductive pollution or dry non-conductive pollution that becomes conductive due to condensation — typical for most control panels without sealed enclosures.