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Siemens 3RA2145-4KD46-1NB3 — Motor Starters

Siemens 3RA2145-4KD46-1NB3 Combo Starter, 57-75A

MPN3RA2145-4KD46-1NB3

Siemens 3RA2145-4KD46-1NB3, SIRIUS 3RA2 combo non-reversing starter, S3 frame, 57-75 A, current lifecycle stage.

Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Product details

The Siemens 3RA2145-4KD46-1NB3 is a SIRIUS 3RA2 combo non-reversing starter in the S3 frame size, rated for the 57-75 A motor current range. A combo starter integrates a contactor and overload relay into a single, pre-wired unit, saving panel space and wiring time compared to assembling discrete components. This part is designed for full-voltage starting of three-phase induction motors in industrial control panels.

The 57-75 A range governs the motor full-load current the starter can handle in AC-3 duty (squirrel-cage motors). The S3 frame size determines the physical footprint on the DIN rail and the busbar connection pitch — verify the panel cutout against the S3 drilling plan before committing the layout.

Frequently asked questions

Does 3RA2145-4KD46-1NB3 include overload protection?

Yes, as a combo starter it integrates the overload relay into the same unit as the contactor, providing motor overload protection within the 57-75 A range.

Is 3RA2145-4KD46-1NB3 a full voltage or reduced voltage starter?

This is a full-voltage (across-the-line) non-reversing starter. It applies full line voltage to the motor on start.

What is the difference between 3RA2145-4KD46-1NB3 and 3RA2145-4KD46-1NA3?

The two order codes share the same S3 frame and 57-75 A current range. The suffix difference (1NB3 vs 1NA3) typically indicates a variation in auxiliary contact configuration or control voltage — check the specific wiring diagram for your application before substituting.

MPN
3RA2145-4KD46-1NB3