Harmonic detection and filtering - Schneider Electric

4.5.4 Reduction in the service life of equipment(Data obtained from the Canadian Electrical Association).When distortion of the supply voltage is in the 10 % range, equipment service life issignificantly reduced. Depending on the type of device, the reduction in service lifemay be estimated at:b 32.5 % for single-phase machinesb 18 % for three-phase machinesb 5 % for transformers.To maintain the service life observed with a normal supply voltage, devices must beoversized.4.5.5 Nuisance tripping and installation shutdownInstallation circuit breakers are subjected to current peaks caused by harmonics.These current peaks cause nuisance tripping and result in production losses as wellas costs corresponding to the time required to put the installation back into runningorder.4.5.6 A few examplesFor the installations in the examples below, the significant economic consequencesmade necessary the use of harmonic filters.b computer centre of an insurance company:in this computer centre, nuisance tripping of a circuit breaker caused a loss estimatedat 100 000 euros per hour of down timeb pharmaceutical laboratory:harmonics provoked the failure of an engine generator set and interruption of a verylengthy test phase on a new product. The estimated loss amounted to 17 millioneurosb metallurgy factory:induction furnaces provoked overloads causing irreversible damage to threetransformers ranging from 1500 to 2500 kVA in one year, and production lossesestimated at 20 000 euros per hourb garden-furniture factory:failure of variable-speed drives provoked production losses estimated at 10 000euros per hour.27