Capacitor switching contactor for power factor correction banks
The Siemens 3RT2627-1AB05 is a SIRIUS capacitor contactor, size S0, designed specifically for switching capacitor banks in power factor correction (PFC) panels. Unlike a standard contactor, the capacitor version includes pre-charge resistors that limit inrush current when the capacitor is switched onto the line, preventing nuisance fuse blowing and contact welding.
Switching capacity and operating limits
These values define the maximum continuous load the contactor can handle in its intended capacitor-switching duty. Arcing time is 10 ms, with a make/break operating time of 4 to 16 ms AC. Maximum switching frequency at 230 V through 600 V is 100 operations per hour; at 690 V it is 72 operations per hour. This limits the contactor to relatively slow cycling, typical of PFC bank switching rather than motor starting.
Wiring capacity and environmental range
At 40 °C ambient, a single 10 mm² conductor is allowed; at 60 °C, two 10 mm² conductors are permitted.