Capacitor switching contactor for power factor correction banks
The 3RT2646-1AF03 is a SIRIUS brand capacitor contactor, size S3, designed for switching capacitive loads in power factor correction (PFC) banks. Unlike standard contactors, this variant includes pre-charge resistors and a dedicated switching sequence that limits inrush current when energising capacitor banks. The magnet coil termination uses screw-type terminals — no push-in or spring cage on the coil connection.
Switching frequency limits by applied voltage
Maximum switching rate depends on the line voltage. These figures govern the capacitor step size and the PFC controller's switching program — exceeding them shortens the contact life and risks contact welding.
Panel fit and termination capacity
Dimensions are 80 mm wide, 140 mm high, 152 mm deep — the depth is the dimension that sticks out from the DIN rail, so allow clearance for the arc chamber and wiring. Main power terminals accept stranded conductors from 10 mm² up to 70 mm² (single or dual), and solid/stranded auxiliary wiring from 0.5 mm² to 4 mm².
Ambient conditions and storage
The contactor includes one instantaneous auxiliary contact (NO/NC configurable depending on variant), and an auxiliary switch block can be attached.