SIRIUS S0 power contactor for motor and resistive loads
The Siemens 3RT1025-1AV04 is a SIRIUS S0-frame power contactor with three normally-open main contacts, intended for switching three-phase motors and resistive loads in industrial control panels. It mounts on a 35 mm DIN rail per DIN EN 50022 via screw or snap-on fixing, occupying 45 mm of panel width. The main circuit uses screw-type terminals rated for 2x (0.75... 4 mm²) solid or 2x 10 mm² stranded conductors.
Motor switching capacity across voltage bands
At 690 V, this contactor handles 11 kW motor load; at 500 V, 10 kW. For AC-2 duty at 400 V, it is rated 7.5 kW. The AC-4 (plugging/inching) rating at 400 V is 15.5 A — a key figure for reversing or jogging applications where the contactor must break stalled-rotor current. The 50 Hz coil operates at 400 V with a tolerance of 0.8 to 1.1 times rated voltage.
Auxiliary contacts and coordination fusing
Two auxiliary contacts (instantaneous) are built in. Their switching capacity varies by voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V DC. For type 2 coordination (no-weld), the required upstream fuse is gL/gG 25 A; for type 1 coordination (allow weld but no fire risk), use gL/gG 63 A. The contactor is rated for pollution degree 3 and operates from -25 °C to +60 °C, with a maximum altitude of 2 000 m.
Panel integration and wiring notes
The 85 mm height and 140 mm depth fit standard S0 contactor footprints. Front face is IP20; terminal area is IP00 (requires panel protection). Side-by-side mounting is permitted with zero clearance between units. Wire sizes: main contacts accept 2x (1... 2.5 mm²) or 2x (2.5... 6 mm²) stranded, up to 2x 10 mm² max; auxiliary contacts accept 2x (0.5... 1.5 mm²) or 2x (0.75... 2.5 mm²) solid, max 2x (0.75... 4 mm²). AWG equivalents: main 2x (16... 12) or 2x (14... 10), single 8 AWG.