The Siemens 3RA2426-8XF32-1AC2 is a factory-assembled SIRIUS contactor assembly for star-delta (wye-delta) motor starting. It ships with three contactors: two 3RT2027-1AC20 units and one 3RT2026-1AC20, plus the RS assembly kit 3RA2923-2BB1 for mechanical interlocking and timing. The S0 frame size keeps the assembly compact at 135 mm wide, 101 mm high, and 171 mm deep — a tight fit for a three-contactor star-delta group in a single footprint.
Mounting and wiring — DIN rail, screw terminals, conductor ranges
AWG equivalents are 2x 16…12 and 2x 14…8 for the main contacts. All power and control connections use screw-type terminals. Clearance distances: 6 mm upwards, forwards, downwards, and to the side; 0 mm backwards — the rear face can sit flush against the panel backplate.
Environmental and mechanical endurance
The assembly withstands shock at 13.5 g / 5 ms and 8.3 g / 10 ms on AC, and 15 g / 5 ms and 10 g / 10 ms on DC. Mechanical life of the contactor typical is 10,000,000 operations. The assembly includes three instantaneous contacts. No auxiliary switch or bus communication extension is fitted as standard. Substance prohibition date is 10/01/2009, indicating RoHS compliance per Siemens declaration.