What it is and where it sits
The ABB 1SAM250000R1009 is a motor protection circuit breaker — the short-circuit and overload element that mounts directly beside a contactor in a starter string, sized at 6.3 A with a Class 10A trip characteristic. It is a 3-pole device, 45 mm wide, 90 mm tall, and 85.6 mm deep, so the DIN-rail footprint matches the standard 45 mm modular slice used across this ABB accessory family and lines up cleanly under a same-frame contactor. In a typical motor-starter assembly, this part takes the place of a fuse + overload combination: it carries the motor load itself, interrupts short-circuit fault current, and provides the adjustable thermal trip element that protects the windings — the contactor handles the switching duty downstream.
Ratings that actually decide the fit
The 6.3 A rated operating current is the headline number, but the figure that really governs fit is the Class 10A trip characteristic, which suits standard AC induction motors. Sizing must be done against the motor's full-load current on the nameplate, not against the 6.3 A label. Operating temperature spans -25 °C to 70 °C, so the device holds its calibration in an unheated enclosure or a hot cabinet near a drive. Derating per the thermal characteristic sheet still applies above 70 °C. Mechanical service life is rated at 100 000 cycles, which sets the maintenance horizon for a line that sees a moderate number of starts per shift; for a high-cycling application, expect to plan a replacement interval well before the contactor wear point.
Footprint, ingress, and wiring
Width 45 mm keeps it on the standard modular pitch; depth 85.6 mm drives the cabinet depth allowance behind the DIN rail — leave room for the same-frame contactor that clips on the load side of the device. Protection rating is IP 20 on the operator side and IP 10 at the terminations, so the front face is finger-safe during normal operation but the wiring side still needs a closed enclosure or shroud before live work. Flexible conductor range is 0.75 mm² minimum to 2.5 mm² maximum. Ferruled ends are recommended at the upper end of the range to keep the cage clamp seated under vibration.