Capacitor switching duty and coil draw
The 3RT2637-1AB03: This is a SIRIUS capacitor contactor (size S2) designed specifically for switching power-factor-correction capacitor banks — the inrush current from a discharged capacitor is handled by the contactor's damping resistors, not the main contacts. The 24 V AC 50 Hz coil draws 6 A at pickup and holds at lower current; the coil connection uses screw-type terminals. Switching frequency is limited by the capacitor discharge cycle: at 230 V and 240 V the contactor can switch 100 times per hour, dropping to 25 cycles per hour at 690 V. This is not a general-purpose contactor for motor starts — the capacitor-specific damping network limits the make/break rate.
Panel fit and wire termination
Main power terminals accept stranded wire from 10 to 50 mm² (single) or 10 to 35 mm² (double). The contactor has one instantaneous auxiliary contact.