The Reactive Power

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An electrical installation in alternating current (AC) with receptors where the current is out of phase with the voltage (transformer, motor, air conditioning, power electronics, etc.), absorbs a total energy called apparent power (S)

Cos (φ) is the sine wave lag between voltage and current, that is, the delay or advance in time through a given point.
The power factor (φ) is the same but adding the effects of harmonics distortion.

The active power (kW) is related to the active energy (kWh) by time.
The active energy is that a receiver needs to be transformed into useful work, light or heat.

Reactive power (kvarh) generated in the windings of the receivers a must to make them work magnetic field.
This energy corresponds Q reactive power (kVAr); that is, to the contrary to the foregoing, unproductive for the receiver.

By increasing the power factor of a facility energy reactive consumption is minimized, and it reverts to:

  • echnical and economic benefits such as:
  • reduction of active energy losses in cables
  • reduction in voltage losses
  • increase active power available (improves “electrical performance” installation) significant savings in electricity bills


An automatic capacitor bank is an equipment capable of detecting the presence of inductive reactive power in an electrical installation, and by connecting capacitors get their groups capacitive reactive power needed to remove it.

Capacitor banks are essential elements to reduce the energy cost of an installation. Improved electrical performance and contribute to the reduction of CO2 emissions into the atmosphere.