LV generator protection - engineering site - Schneider Electric

E79475EGSRemote control 2Remote control 1PrioritymotorsPriorityresistive loadsFigure 16: Restarting of priority motors (Σ P > 1/3 Pn).Restarting tips:b if the Pmax of the largest motor > 1/3 Pn, a progressive starter must beinstalled on this motorb if Σ Pmotors > 1/3 Pn, motor cascade restarting must be managed by a PLCb if Σ Pmotors < 1/3 Pn, there are no restarting problems.3.3.3. Non-linear loads - Example of a UPSNon-linear loadsThese are mainly:b saturated magnetic circuitsb discharge lamps, fluorescent lightsb electronic converters:v computer processing systems: PC, computers, etc.v etc.These loads generate harmonic currents: supplied by a Generator Set, this cancreate high voltage distortion due to the low short-circuit power of the generator.Uninterruptible Power Supply (UPS)The combination of a UPS and generator set is the best solution for ensuringquality power supply with long autonomy for the supply of sensitive loads.It is also a non-linear load due to the input rectifier. On source switching, theautonomy of the UPS on battery must allow starting and connection of theGenerator Set.21