Power Factor Correction Contactors

A power factor correction contactor is a contactor designed for switching capacitors, which limits the high inrush current produced when a capacitor step is energized by means of its pre-insertion resistors and early-closing contacts. It is used in automatic power factor correction panels, driven by the output of the reactive power relay, to switch capacitor steps on and off. In this category, contactors from brands such as Entes, Tibcon and ABB are offered in step ratings such as 10 kVAr, 12.5 kVAr, 20 kVAr, 25 kVAr and 33 kVAr. Choose the contactor by the kVAr power of the step and the grid voltage, the coil voltage by the panel's control voltage, and the auxiliary contact configuration by the control diagram. The kVAr value a contactor can switch varies with voltage; for different voltages, refer to the manufacturer table. Capacitor switching is defined in IEC 60947-4-1 by utilization category AC-6b. A standard motor contactor selected by its AC-3 rating risks contact welding under the capacitor's inrush current and is not a substitute for a power factor correction contactor.

Products

How to choose Power Factor Correction Contactors

A power factor correction contactor is a contactor designed for switching capacitors, which limits the high inrush current produced when a capacitor step is energized by means of its pre-insertion resistors and early-closing contacts. It is used in automatic power factor correction panels, driven by the output of the reactive power relay, to switch capacitor steps on and off.

  • Take reactive power demand and harmonic distortion levels from site measurements or project calculations.
  • Compare kVAr step sizes, rated voltage and step count against the compensation panel layout.
  • Select capacitor duty contactors, harmonic filter reactors and discharge resistors together with the capacitor bank.

Frequently asked questions

What is Power Factor Correction Contactors and where is it used?

A power factor correction contactor is a contactor designed for switching capacitors, which limits the high inrush current produced when a capacitor step is energized by means of its pre-insertion resistors and early-closing contacts. It is used in automatic power factor correction panels, driven by the output of the reactive power relay, to switch capacitor steps on and off.

What should I compare when choosing Power Factor Correction Contactors?

Choose the contactor by the kVAr power of the step and the grid voltage, the coil voltage by the panel's control voltage, and the auxiliary contact configuration by the control diagram.

Where can I find technical details for Power Factor Correction Contactors products?

A standard motor contactor selected by its AC-3 rating risks contact welding under the capacitor's inrush current and is not a substitute for a power factor correction contactor.

Power Factor Correction Contactors Selection Guide: Technical Criteria & Application Standards