Top nine power problem that could be protected by UPS Device

UPS (Uninteruptable Power Supply) is a device that give a temporary power line for every device. Below top nine problem that could be protected by UPS device

1. Power failure
2. Power sag (undervoltage for up to a few seconds)
3. Power surge (overvoltage for up to a few seconds)
4. Brownout (long-term undervoltage for minutes or days)
5. Long-term overvoltage for minutes or days
6. Line noise superimposed on the power waveform
7. Frequency variation of the power waveform
8. Switching transient (undervoltage or overvoltage for up to a few nanoseconds)
9. Harmonic multiples of power frequency superimposed on the power waveform

PC Disaster and Recovery by Kate J. Chase Sybex 2003