Why the power factor of diesel generator is always 0.8?
This is the worst power factor they are intended to handle, so is an arbitrary number based on the expected worst power factor of normal loads. The power (KW) is related to the horsepower of the engine, the output it can generate without overheating or shortening the engine life in some way. The KVA output is related to the current the generator winding and connections can handle without overheating, and is more than the current expected from the kilowatt rating. The difference between KVA and KW ratings is due to the power factor, the need to carry extra circulating currents caused by part of the load not being resistive.. It is used to charge inductance and/or capacitance in the load, so there is no work done.
