The 3RT1647-1AN21: The AC-6 rating at 50 kVAr / 400 V is the key figure — it's specifically for switching capacitor banks, where inrush currents can reach tens of times the steady-state value. A standard contactor rated AC-3 or AC-1 at the same apparent power would weld its contacts on the first capacitor energization. The 90 A AC-1 rating at 400 V gives the resistive-load capability for reference. The 220 V AC coil draws from the control transformer, not the capacitor bus.
Panel Integration
Side-by-side mounting is permitted. The 70 mm width matches the S3 frame footprint — fits alongside other SIRIUS S3 contactors and overload relays on the same rail. IP00 on the terminals; IP20 on the front with the supplied cover or box terminal installed.
Rated for -25 to +60 °C ambient during operation. The substance prohibitance date of 05/01/2012 indicates RoHS compliance from that point forward.