Frame size and what it means for your panel
The 3RA2220-1HB24-0AP0: This is a Size S0 reversing starter from the Siemens SIRIUS family. If your motor nameplate exceeds those numbers, you need the next frame up. The starter ships with the 3RT2024-1AP00 contactor and the 3RA2921-1AA00 link module already assembled. That means the reversing interlock and mechanical linkage are factory-set — no extra wiring or alignment work during installation.
Trip Class 10 — why it matters for motor protection
Trip Class 10 means the overload relay will trip in 10 seconds or less at 600% of the motor full-load current. That is fast enough to protect a standard induction motor during a stall or jam, but slow enough to let the motor start without nuisance tripping on normal inrush. For high-inertia loads like fans or flywheels you might need Class 20 or 30 — but for pumps, compressors, and conveyors, Class 10 is the standard pick.
Mounting flexibility — DIN rail or screw
The fastening method is an adapter that supports both snap-on mounting on 35 mm DIN rail and screw mounting. That covers new builds where you run DIN rail across the backplate and retrofits where the existing panel has drilled holes. Mounting position is vertical only — do not lay it on its side or the thermal overload calibration shifts. Clearance spaces: 50 mm above, 32 mm in front, 10 mm below, 10 mm at the sides, 0 mm behind. The zero behind means it sits flush against the mounting surface — no extra gap needed for airflow behind the unit.
Voltage and current ratings — the real operating envelope
Rated insulation voltage is 690 V, and the maximum AC-3 operating voltage is also 690 V. At 480 V the rated current is 8 A; at 600 V it is also 8 A — no derating between those two voltages. At 230 V the rating is 1 hp.
Environmental limits and storage
Operating temperature range is -20 to +60 °C, storage and transport range is -50 to +80 °C. The temperature compensation is active across the full operating range, so the overload trip curve stays accurate whether the panel is in a cold warehouse or a warm machine room.