Capacitor switching, not general-purpose
The Siemens 3RT2636-1AV03 is a capacitor contactor rated AC-6b for 50 kVAr at 400 V, 3-pole, with a 400 V AC 50 Hz coil. That AC-6b utilisation category means it's designed to switch capacitor banks — the inrush current when energising a discharged capacitor can hit 100× the rated current, and a standard contactor's contacts would weld. This one handles the pre-charge surge without sticking.
Size S2 frame, screw terminals, with one NO and one NC auxiliary contact built in. The screw terminals take up to 35 mm² cable, and the S2 footprint fits standard DIN-rail mounting in a motor control centre or power factor correction panel. No extra aux block needed for basic status feedback — that 1 NO + 1 NC covers the PLC input and the run-permissive interlock.