The 3RA6250-1BB33: That figure sets the short-circuit current rating (SCCR) for the motor branch circuit — downstream components must be coordinated to this level, or the starter itself clears the fault without upstream breaker intervention. Trip Class is adjustable between CLASS 10 and CLASS 20. CLASS 10 trips faster on overload, protecting motors with short thermal time constants (e.g., submersible pumps); CLASS 20 allows longer inrush for high-inertia loads like fans or centrifuges. The same starter covers both without a heater swap. That universal control voltage simplifies panel wiring — one control transformer covers the whole cabinet, and the DC rating means it works on battery-backed safety circuits.
DIN rail footprint and wire termination
Mounts on standard 35 mm DIN rail via screw and snap-on fastening. Any mounting position is allowed, so it fits in tight sub-panels or vertical bus risers without derating. Dimensions are 90 mm wide, 170 mm high, 165 mm deep. That 90 mm width is three 18 mm modular units — plan for three adjacent pole spaces on the DIN rail. The dual-entry allows looping through the same terminal for daisy-chained control wiring without a separate jumper. Main circuit connection is plug-in without terminals — the power contacts are part of the base unit; the control module plugs onto it. That means you can replace the overload/control section without pulling the power wiring.
Environmental and mechanical ruggedness
Operating temperature range is -20 to +60 °C; storage and transport range is -55 to +80 °C. That covers unheated warehouses and truck-bed exposure in most climates. Shock resistance is 60 m/s² (6g) with 10 ms half-sine, 3 shocks per axis. Vibration withstand is 4–5.8 Hz at 15 mm displacement, then 5.8–500 Hz at 20 m/s² acceleration, 10 cycles per axis. These are machine-mounting ratings — the starter lives on a conveyor frame or pump skid, not just a back-panel. Power dissipation is 2.8 W AC maximum, 2.9 W DC maximum. In a sealed enclosure with multiple starters, that heat adds up — budget about 3 W per unit for thermal calculations.
Lifecycle and sourcing — current production, quoted to order
Lifecycle status is current production. This is not an end-of-life or NRND part — Siemens continues to manufacture the 3RA6250-1BB33 as an active catalog item. The 6ES7517-3FP00-0AB0 and 6AG1215-1BG40-5XB0 listed as peers are Siemens PLC CPUs, not motor starters — they are not functional replacements and do not share the same mounting or wiring footprint. Sourced through independent distribution channels. No stock-holding claim is made; each order is quoted individually.