Battery Equivalents and Replacements

Kilowatts (kW) to Amps (A) Calculator

Convert kilowatts (kW) to Amps (A) using our conversion calculator. Also, learn more about relations between Amps (A), Voltage (V), Watts (W), and other units often used not only in Electrical Engineering but in many other walks of life.

Published: February 2, 2024.


Kilowatts to Amps Conversion Calculator

In order to convert kilowatts (kW) to Amps (A), feel free to use this conversion calculator - write your values and click 'Calculate' to convert them.

Kilowatts (kW) to Amps (A)

 

 

Note: Phase shift must be ≤1. If you are unsure, leave the default value (1).

To convert Amps to Kilowatts, feel free to check our Amps (A) to Kilowatts (kW) Calculator article.


How to Convert Kilowatts to Amps and Other Formulas

Before diving into math and physics, it is important to know which unit is used for what:

  • 'I': current strength, measured in Amps (A),
  • 'P': power, measured in Watts (W),
  • 'U': potential difference, measured in Volts (V),

In order to convert kilowatts (kW) to Amps (A) one must use two different (although similar) formulas (based on Ohm's Law Wheel), one for Direct Current (DC) and another for Alternate Current (AC):

DC:

P (W) = I (A)  *  U (V)

AC:

P (W) = I (A) * U (V) * cos α

Note: α is the phase angle between voltage and current - in DC electric systems α=0° (cos 0°=1), while in AC electric systems α depends on the type of load (inductive or capacitive) - this is the Effective Power of AC electric system and is expressed by Watts.

The Apparent Power of AC systems is expressed in Volt-Amps (never in watts) and is obtained by multiplying Volts and Amps.

So, to convert kilowatts to Amps, we will use the following formula:

I (A) = [P (kW) * 1000] / [U (V) * cos α]

Note: cos α is also known as the "Power Factor," and if it is below 0.9, the system is usually considered inefficient. But, there are various applications, so it may vary...


Kilowatts to Amps Conversion Example

Imagine that we have an AC system that outputs 9kW at 120V, with a power factor of 0.95. What is the current?

In this example, the current is:

I (A) = [9kW * 1000] / [ 120V * 0.95] = 9000W / 114V = ~78.947 Amps


Apparent Power (Complex Power) vs. Real Power (True or Working Power) vs. Reactive Power

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In the context of electrical power systems, understanding the distinctions between Apparent Power, Real Power, and Reactive Power is fundamental for both engineering applications and energy management.

These concepts reflect the different dimensions of power in AC (Alternating Current) circuits, where the relationship between voltage and current can vary significantly.

Apparent Power (Complex Power)

Apparent Power, often denoted as S and measured in Volt-Amperes (VA), represents the total power flowing through an electrical system.

It combines both the power that performs work (Real Power) and the power stored and released by the system's reactive components (Reactive Power).

Apparent Power is considered "complex" because it accounts for the vector sum of the real and reactive power, reflecting both the magnitude and phase relationship between voltage and current.

It is calculated as the product of the root-mean-square (RMS) voltage and RMS current without considering the phase angle between them.

Real Power (True or Working Power)

Real Power, denoted as P and measured in Watts (W), is the power that actually performs work in an electrical circuit. It is the power used by electrical devices to produce work, such as turning a motor or illuminating a light bulb.

Real Power is the portion of Apparent Power that, after being consumed, results in actual work done or heat generated. In purely resistive circuits, where voltage and current are in phase, the Real Power equals the Apparent Power.

However, in circuits containing inductive or capacitive elements, Real Power is less than the Apparent Power due to the phase difference between current and voltage.

Reactive Power

Reactive Power, denoted as Q and measured in Volt-Amperes Reactive (VAR), represents the power that oscillates between the source and the reactive components of an electrical system (such as inductors and capacitors).

This power does not perform any work but is necessary for establishing the electric and magnetic fields that enable the system's reactive components to function. Reactive Power contributes to the total Apparent Power but does not translate into useful work output.

It results from the phase difference between voltage and current, leading to power flow that alternates direction and effectively "reacts" back and forth within the circuit.

Key Differences

Apparent Power is the vector combination of Real and Reactive Power, indicating the total power flow within a system, including both working and non-working components.
Real Power is the component of power that performs actual work in a circuit, directly affecting the energy consumption and efficiency of electrical devices.

Reactive Power is necessary for the operation of reactive components within a circuit but does not contribute to the work output; it influences the voltage and current phase relationship and the overall power system's stability and efficiency.

Understanding these distinctions is crucial for the design, analysis, and optimization of electrical systems, especially for ensuring efficient energy use and maintaining power quality in both residential and industrial settings.