1. Power Failure - A total loss of utility power. Can be caused by lightning strikes, downed power lines, grid overdemands, accidents and natural disasters.
2. Power Sag - Short-term low voltage. Triggered by the startup of large loads, utility switching, utility equipment failure, lightning and power service that is too small for the demand. In addition to system crashes, sags can damage hardware.
3. Power Surge - Also known as a spike. Short-term high voltage above 110% of nominal. Surges can be triggered by a rapid reduction in power loads, heavy equipment being turned off or by utility switching. The result can damage hardware.
A Level 3 UPS can handle ALL of the above Power Occurrences
4. Undervoltage - Also known as a brownout. Reduced line voltage for extended periods ranging from a few minutes to a few days. Can be caused by an intentional utility voltage reduction to conserve power during peak demand periods or heavy loads that exceed supply capacity.
5. Overvoltage - Increased line voltage for extended periods ranging from a few minutes to a few days. Can be caused by a lightning strike that sends line voltages to levels in excess of 6,000 volts. A spike almost always results in data loss and/or hardware damage.
A level 5 UPS can handle ALL 5 of the above Power Occurrences
6. Electrical Line Noise - High Frequency waveform interference. Can be caused by either Line RFI or EMI interference generated by transmitters, welding devices, SCR-driven printers and lightning.
7. Frequency Variation - A change in frequency stability, resulting from generators or small co-generation sites being loaded and unloaded. Can cause erratic operation, data loss, system crashes and equipment damage.
8. Switching Transient - Instantaneous undervoltage (notch). Normal duration is shorter than a spike and generally falls in the range of nanoseconds.
9. Harmonic Distortion - Distortion of the normal waveform, caused by switch-mode power supplies, variable speed motors and drives, copiers and fax machines, and other non-linear
loads. Can result in communication errors, overheating and hardware damage.
A Level 9 UPS can Handle ALL 9 of the above Power Occurrences