The adjustment of reactive load is realized by changing the size of the field current. While the reactive load is adjusted, attention shall be paid to: 

1. When the reactive power increases, the stator current and rotor current do not exceed the specified value, that is to say the power factor shall not be too low. The too low power factor means that the reactive power is too big, in this way the rotor winding may be overheated. 

2. The rated capacity, the stator current, power factor of the generator are corresponding, so if the rated value of field current is maintained and the power factor operation is lowered, then the active power output must be reduced, otherwise the capacity will exceed the rated value. 

3. When the reactive power is reduced, it is required to notice that the power factor phase-in is not allowed.