Page 793 - Basic Electrical Engineering

excitation, the current drawn by the motor will be minimum, which will be
equal to OC. The current drawn will be at unity power factor as V and I will
a
be in phase. The excitation current at which the motor draws unity power
factor current is called normal excitation. Excitation current higher than the

normal excitation current is called over excitation. Excitation current lower
than the normal excitation is called under excitation.