The Siemens 3RT1946-6D is a replacement contact set for the SIRIUS 3RT1 contactor family, Size S3. It consists of three movable and six fixed main contacts with mounting hardware — a direct-fit spare for a three-pole contactor in AC-1 resistive duty rated at 140 A. This is a phased-out product line; the official successor is the SIRIUS 3RT2 series.
The AC-1 rating of 140 A governs resistive or lightly inductive loads (heaters, lighting banks) where inrush is negligible. For motor duty (AC-3), the contactor's own rating will be lower — this contact set restores the contactor's original AC-3 capability, not a higher one. The set includes three NO main contacts, matching the standard three-pole contactor configuration.