Why Generator Is Rated In Kva And Motor In Kw?
Generators and alternators are rated in kVA because they produce both active and reactive power, expressed in volt-amperes (VA) rather than watts (W).
The most important factors considered by manufacturers when designing electrical and power equipment such as transformers, UPS, alternators generators, etc. are the load and the power factor.
Because they don’t know exactly what the power factor is and what type of load (resistive, inductive, capacitive, or a combination thereof) will be connected to the device and devices.
You then simply design and classify an electrical device based on its maximum output power that the cables can safely transmit, taking into account the unity power factor (in the case of a purely resistive load).
For this reason, the apparent power measured in kVA is considered the nominal power of the generator¹⁵.
On the other hand, engines are specified in kW because they only consume active power in watts at the input and deliver mechanical power in horsepower or kW to the crankshaft at the output.