SIRIUS direct-on-line starter, Size S0 — 10 A AC-3, 24 VDC coil
The 3RA2120-1JD24-0BB4: It's a factory-combined unit — the supplied contactor is a 3RT2024-1BB40 and the link module is a 3RA2921-1BA00, so you're getting a coordinated starter package, not a loose pile of parts. The 24 VDC coil (24... 24 V) means this starter is a natural fit for modern PLC-controlled panels running a 24 VDC control bus — no separate AC control transformer needed for the starter itself.
Mounting on 60 mm busbar systems — panel integration
This starter is designed specifically for snapping onto 60 mm busbar systems — the mounting method is a fastening clip, not DIN rail. That makes it a good fit for Siemens 8US busbar systems or similar 60 mm-center distribution assemblies where you want to tap power directly off the bus without extra wiring. Mounting position is vertical only. The dimensions are 45 mm wide, 260 mm tall, and 165 mm deep — the width is the critical panel pitch dimension, and at 45 mm it fits standard S0 feeder spacing. Required clearances: 50 mm upward, 20 mm forward, 10 mm downward, 20 mm at the sides, and zero backward. That backward-zero clearance means it can sit flush against a panel backplate or busbar support. Main circuit connections are screw-type terminals — no spring-cage here, so factor in screwdriver torque time during panel build. The supplied link module (3RA2921-1BA00) bridges the contactor to the upstream circuit breaker, keeping the wiring between the protection and switching elements internal to the starter assembly.
Duty ratings and motor sizing across voltages
At 480 V and 600 V the current rating also holds at 10 A — so this starter handles the same 10 A motor load across the common North American and European voltage bands. Use the 10 A AC-3 figure as your sizing anchor. Ambient operating range is -20 to +60 °C, with storage and transport range of -50 to +80 °C. The temperature compensation is also rated -20 to +60 °C, meaning the thermal overload characteristic stays within spec across that band without manual adjustment.