Wednesday, 15 January 2020

What is kVA and how is it calculated?

We all know that power ratings are shown in different forms. We are familiar with ‘Watts’, ‘Kilowatts’, ‘Amps’, ‘Volts’. However, outside the diesel generator industry not many are fully aware of the definition of kVA. and how it is calculated. A Kilowatt (kW) is a more popular term as that is how electrical equipment is usually rated.

Actual power vs Apparent power

To put it in a nutshell, the difference between Kilowatts and kVA is the difference between actual power and apparent power. 

kVA describes the total amount of power being used - in a 100% efficient system kW and kVA will be the same. In practice, however, electrical systems are not 100% efficient, hence not all of the system’s apparent power is being converted. 

In theory, one kVA is equal to 1,000-volt amps. Whereas, a volt is for measurement of electrical pressure, an amp is a way of electrical current measurement. A term called apparent power (the absolute value of complex power, S) is equal to the product of the volts and amps.

A diesel genset is engineered with a power factor of 0.8. With this information, it is easy to convert kVA to kW - as the efficiency level of the electrical system in question is known. Electrical efficiency is expressed as a power factor in between 0 & 1 - and the closer the power factor is to 1, the higher the efficiency of kVA converted into actual kilowatts. 

Calculation of kW to kVA: -

Apparent power (kVA) x power factor (pf) = actual power (kW)
e.g. 100 kVA x 0.8 = 80 kW
The formula for converting kW into kVA is:
Actual power (kW) / power factor (pf) = apparent power (kVA)
1 ton = 200 BTU/minute
1 ton = 12,000 BTU/hour
1 ton = 3.517 kilowatts

Mahindra Powerol deals in high kVA gensets that are extremely fuel efficient and robust.
To know more about our products and the industries we cater to visit our website at: - or call us at 1800-419-1999

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