Electricity units converter, calculator

Active power is measured in kilowatts (kW), while apparent power is measured in kilovolt-amperes (kVA).

 

Volt-amperes (VA) and kilovolt-amperes (kVA) are units of alternating current power. They are calculated by multiplying the current in the circuit (in amperes) by the voltage across its terminals (in volts).

 

Watts (W) and kilowatts (kW) represent the power needed to perform work equal to 1 joule in 1 second. The wattage measures the power of a direct electric current, where 1 ampere flows at a voltage of 1 volt.

 

It is important to note that only a portion of the apparent power (in VA) is utilized for doing work; the remainder is dissipated as heat.

 

This distinction indicates that apparent power and active power are different physical quantities.

 

The power factor is the ratio of active power to apparent power, with a maximum value of one. 

 

For instance, in the case of an uninterruptible power supply (UPS), if the total power is 5 kVA and the active power is 4.5 kW, the power factor of the UPS is 0.9. Therefore, the UPS should be used with a load not exceeding 4.5 kW.