What this SIRIUS direct starter delivers
The 3RA2120-1KD24-0BB4 is a SIRIUS direct-on-line starter combining a contactor and overload relay in a single S0-size package, pre-assembled for 60 mm busbar mounting. The 24 VDC control voltage (24... 24 V) matches common PLC output rails; the supplied contactor is 3RT2024-1BB40 and the link module is 3RA2921-1BA00, so the assembly is ready to wire out of the box.
Mounting and panel fit
Snaps onto 60 mm busbar systems — the fastening method is designed for that rail spacing, not standard DIN rail. Dimensions are 165 mm deep, 45 mm wide, 260 mm tall. Clearance requirements: 50 mm upward, 20 mm forward, 10 mm downward, 20 mm at the side, zero backward.