What this part is and what it's for
The Siemens 3RT1647-1AV01 is a SIRIUS capacitor contactor, Size S3, designed for switching capacitor banks in power-factor correction (PFC) panels. It is rated AC-6 at 50 kVAr / 400 V, 50 Hz, with three main poles and one normally-open auxiliary contact. The coil is AC-operated at 400 V, 50 Hz. AC-6 duty is the standard utilisation category for switching capacitor loads — the contactor must handle high inrush currents without welding its contacts. The 50 kVAr rating at 400 V means it can switch a capacitor bank of that size in a typical 400 V three-phase network. The 90 A rating at AC-1 (resistive) confirms the contactor's thermal capacity.
Mounting and integration
Mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 50022. Side-by-side mounting is permitted with no gap. The contactor is 70 mm wide, 167 mm tall, and 183 mm deep — Size S3 footprint. Main and auxiliary circuits use screw-type terminals. The front face carries IP00 protection; IP20 is achieved only with the supplied cover or box terminal installed.
Environmental and compliance
Operates in ambient temperatures from -25 °C to +60 °C. The substance prohibitance date of 05/01/2012 indicates RoHS compliance from that date forward. No UL or CSA listing is stated in the available specs — verify with your local Siemens office if those marks are required for your jurisdiction.