Energy Planning Network: Surge Protection Basics (May 2000)
Given today’s sensitive electronic devices, small power disturbances can cause major problems. The power conditioning industry has grown to address the following factors surrounding power disturbances.
Harmonics are higher frequencies mixed in with the base 60-cycle frequency. Harmonics are much lower in frequency than traditional noise. Harmonics are not random and occur at multiples of the 60-cycle base frequency. In addition, significant power can be involved with harmonics. Harmonics are usually created by power electronic devices such as variable-speed drives and battery chargers/rectifiers.