Q:

What is the difference between kva and kw?

A:

While both kVA and kW are units of measure, kVA is a kilo volt amperes and kW is a kilowatt. Both the kVA and the kW are units used to express power.

kVA is known as the apparent power of an electrical system or of a particular circuit. In direct current circuits the kVA is equal to the kW because the current and the voltages do not get out of phase. However, "real power" and "apparent power" differ in their alternating current circuits so kW is the amount of actual power that does valid work where only a fraction of kVA is available and accessible to do work while the rest is in excess in the current.

The relationship between kVA, kW and the power factor is described mathematically as: kW = kVA x power factor; kVa = kW/power factor; and power factor = kW/kVA. In DC circuits, there is no difference between the kVA and the kW because of the power factor. The power factor leads or lags depending on the way that the load shifts the phase of the current compared to the phase of the voltage. This creates a unity in the DC circuits. In AC circuits, voltage and current may get out of phase leading to a difference in kW and kVA that will be based on the power factor (or how much leading or lagging occurs).


Is this answer helpful?

Similar Questions

  • Q:

    What is the difference between faradic and galvanic current?

    A:

    A faradic current is an alternating, asymmetric current that stimulates muscles throughout its nerve, according to the University of Buffalo. A galvanic current is a term mostly used in medicine meaning a direct current of steady flow.

    Full Answer >
    Filed Under:
  • Q:

    What is the difference between an amp and a volt?

    A:

    An ampere (or amp) is a measure of the amount of electricity, called "current," in a circuit, while voltage is a measure of the force behind that electricity's motion. In a common textbook analogy in which a circuit is imagined as a garden hose, current (measured in amps) would be the volume of water within the hose and voltage would be the pressure that pushes it onward.

    Full Answer >
    Filed Under:
  • Q:

    What is the difference between a cell and a battery?

    A:

    The difference between a cell and a battery is that a cell is a single unit that converts chemical energy into electrical energy, and a battery is a collection of cells. According to About.com expert Mary Bellis, each cell contains two electrodes and an electrolyte, a substance that reacts chemically with each electrode, generating an electrical current. Aggregating cells into a battery increases the electrical voltage they produce.

    Full Answer >
    Filed Under:
  • Q:

    What is the difference between a blackout and a brownout?

    A:

    A blackout is the result of a total power outage, and a brownout is a reduction in the output of energy by an electric provider. Brownouts are sometimes intentionally produced in an effort to avoid a blackout while problems with system voltage are corrected.

    Full Answer >
    Filed Under:

Explore