The Siemens 3RA2220-4AB26-0AK6 is a SIRIUS reversing starter — one compact unit that combines a reversing contactor and a thermal overload relay in a single S0 frame size, ready to bolt into a panel and reverse a three-phase motor on command. It ships with the contactor (3RT2026-1AK60) and link module (3RA2921-1AA00) already assembled and wired internally, saving the panel-builder the time of wiring two contactors and an interlock separately. The coil range covers 88–121 V at 50 Hz and 96–132 V at 60 Hz, so it lands on common control voltages across North American and European panels without a transformer swap. Rated for motor duty at 7.5 kW on 400 V (AC-3) and 14 A at 480 V, with horsepower ratings of 5 hp at 220/230 V, 10 hp at 460/480 V, and 10 hp at 575/600 V — the 480 V figure is the one most buyers will size against for 10 hp US motors.
The S0 frame size is the middle tier in the SIRIUS feeder family — larger than S00 (up to about 5.5 kW) but smaller than S2/S3 (above 18.5 kW). It handles the 7.5–11 kW band that covers most small conveyor, pump, and fan reversing applications. It protects the motor during a stall or jam without nuisance-tripping on a normal start.
Mounting position is vertical only — horizontal mounting would change the thermal overload calibration and void the trip curve. Envelope is 265 mm high, 90 mm wide, 120 mm deep — the depth is the dimension that reaches back from the rail, so plan for at least 120 mm of clear depth behind the panel door. Clearance requirements: 50 mm above, 10 mm below, 10 mm to the side, 32 mm in front. No clearance needed behind the unit (0 mm backwards) since the adapter handles the rail offset. Power connections use screw-type terminals — standard for the S0 frame, no special crimp tool needed, just a good PZ2 or flathead.