What this reversing starter does that a standard contactor pair cannot
The 3RA2220-1JD24-0AP0 is a SIRIUS reversing starter — a factory-integrated assembly of a reversing contactor pair, overload relay, and link module in a single S0 frame that snaps onto 60 mm busbar systems. Unlike wiring two separate contactors with mechanical interlocks, this unit ships with the supplied contactor 3RT2024-1AP00 and link module 3RA2921-1AA00 already coordinated for reversing duty. The Class 10 trip curve means it protects standard squirrel-cage motors against overload during acceleration without nuisance tripping on normal starting current — the thermal memory tracks motor heating between reversals.
Mounting and panel fit — the 60 mm busbar constraint
This starter is designed specifically for snapping onto 60 mm busbar systems — not DIN rail. The 90 mm width and 260 mm height define the footprint; the 155 mm depth is the projection from the busbar face, so verify the enclosure depth allows for the forwards clearance of 32 mm plus cable bending radius. Mounting position is vertical only. The upwards clearance of 50 mm and downwards 10 mm are the minimum free air space for heat dissipation from the S0 frame at full load.
Duty ratings that matter for motor selection
Rated insulation voltage is 690 V — the maximum AC-3 switching voltage for motor duty. At 400 V it handles motors up to 4 kW; at 480 V the current limit is 10 A, and at 600 V also 10 A. The 0.25 hp at 50 Hz is a fractional rating for light-duty reversing. Operating ambient range is -20 to +60 °C with temperature compensation active across the same band — the overload relay adjusts trip threshold for enclosure ambient, not motor winding temperature.
The supplied contactor and link module are standard SIRIUS components, so service spares are straightforward.