Can be caused by a number of events: lightning strikes, downed powerlines, grid overdemands, accidents & natural disasters.

Triggered by the startup of large loads, utility switching, utility equipment failure, lightning & power service that's too small for the demand. In addition to crashes, sags can damage hardware.

Can be caused by lightning strikes & can send line voltages to levels in excess of 6,000 volts. A spike almost always results in data loss or hardware damage.

Can be caused by an intentional utility voltage reduction to conserve power during peak demand periods or other heavy loads that exceed supply capacity.

Can be caused by either RFI or EMI interference generated by transmitters, welding devices, SCR driven printers, lightning, etc.

Overvoltage can be triggered by a rapid reduction in power of loads, heavy equipment being turned off & on or by utility switching. The results can potentially damage hardware.

Resulting fom generators or small co-generation sites being loaded & unloaded. Frequency variation can cause erratic operation, data loss, system crashes & equipment damage.

Normal duration is shorter than a spike & generally falls in the range of nanoseconds.

Switch mode power supplies, variable speed motors & drives, copiers & fax machines are examples of non-linear loads. Can cause communication errors, overheating & hardware damage.