The Siemens 3RT1627-1AF01 is a SIRIUS capacitor contactor rated AC-6 at 25 kVAr / 400 V, 110 V AC 50 Hz coil, 3-pole, Size S0. It switches capacitor banks for power-factor correction — the AC-6 rating specifically covers capacitor switching, where inrush currents can exceed the steady-state rating. The 35 A rated value reflects the continuous current capacity for this duty. Side-by-side mounting is permitted with no spacing required. The coil draws 110 V AC at 50 Hz only — no dual-frequency or DC coil option on this variant.
This part is marked as a phased-out product. The official Siemens preferred successor is 3RT2627-1AF05. For existing BOM lines or installed panels, the replacement drops into the same Size S0 footprint and DIN-rail mounting, with the same 3-pole, 110 V AC 50 Hz coil voltage and AC-6 capacitor switching rating.
Integration Notes
One normally-open auxiliary contact is built in (no NC). The contactor is 45 mm wide, 100 mm high, 135 mm deep — verify panel depth clearance, especially with auxiliary blocks added. For capacitor bank switching, ensure the inrush current from the capacitors does not exceed the contactor's making capacity. The AC-6 rating at 25 kVAr per 400 V is the design point — match the capacitor bank kVar to this figure.