Capacitor Duty Contactor

Capacitor Duty Contactor

Product Application


In Low Voltage installations, when a Capacitor is switched

ˈONˈ,  it results in resonant circuit damped to a greater

degree. In addition to the rated current, over current of high

amplitude(>180 In) and high frequencies (3~15KHz) occur

during transit period (1 to 2 ms). The resultant high

in-rush current peaks, caused due to capacitor switching,

depends upon following factors:

  • ·         Network inductances
  • ·         Transformer power and short cicuit voltage
  • ·         Type of power factor correction: fixed or automatic
  • ·         Harmonics presence in the system


The in-rush current of such high magnitudes is undesirable

and it is likely to weld main poles of any standard contactor.

Therefore, contactor for capacitor bank switching must be

  • designed to withstand:
  • ·         Permanent current that can reach 1.5 time the nominal
  • current of capacitor bank
  • ·         Short but high peak current on pole closing


Hence, selection of capacitor duty switching device requires

careful product selection. It is always recommended to use

dedicated Capacitor Duty Switching Contactor for switching

Capacitor bank, which optimizes the switchgear cost &

enhances the equipment life.


Operating  principal

Capacitor contactor are specially designed to meet stringent requirements of capacitor switching as deliberated above. These contactors are fitted with front-mounted block of 3 early make auxiliary contact in series with quick discharge damping six- resistors-2 per phase to limit peak current to value within contactor making capacity such that normal rated capacitor current is carried by main contacts which, after closing, effectively short out the resistors.


  • Product Range
  • ·         Eight Ratings:  10KVAR ~ 60KVAR
  • 3P, 415VAC , 50/60 Hz
  • ·         Conforms to IEC 60947-4-1 and IS 13947-4-1 AC-6b utilization category

  • Features and Benefits
  • ·         Excellent damping of in-rush Current
  • ·         Reduced watt loss during ON condition, saves energy
  • ·         Capacitor Bank Switching in parallel without de-rating
  • ·         Enhanced equipment life
  • ·         Low maintenance & down-time
  • ·         Power quality improvement
  • ·         Optimized solution cost
Standard and option features
Technical Data