The following are some of the effects of underfrequency
- High flux density in electric machinery, thereby causing higher magnetizing currents.
- High core loss and over-heating of the machines and possible failure.
- Lower efficiency
- Reduction in speed
- The fault level increases due to reduced reactance
Underfrequency situations can be avoided by the installation of underfrequency relays which isolate systems and machinery in the event of an underfrequency.