Load testing is an essential part of the maintenance regime for generators. Placing a 100 percent capacity load on a generator and allowing it to run for awhile not only brings to light any problems in the generator and in the engine and its cooling system; it also benefits the engine by properly seating the rings and dislodging in the combustion chambers and on the valves.
Diesel engines especially need a periodic load test in order to maintain performance and fuel economy.In the Generator industry it is normal practice to specify the rating of the generator as a kVA level at power factor 0.8. e.g. 2200kVA generator would have kW rating of 1760kW
The kWe output of the generator is limited by the engine power capability kWm
A.C. generators perform satisfactorily at any power factor in the range of 0.8 p.f. lagging to unity p.f. Lagging power factors below 0.8 requires alternator de-rating while leading power factor loads need to be referred to the supplier for special considerations