1,low frequency online ups 2,IGBT technology 3 ... difference ±1% , dynamic difference <±3%Frequency50/60Hz±0.5%Harmonic Distortion<3%(THD)under full linear loadingOverload ... AC95%LCD displayDisplay Infostatus display, voltage input/output, frequency, loading,working temperature , DC voltage etc.Status DisplayWorking ... %-90% non-condensingWorking HeightBelow 5000 feet Low-Frequency online UPS 3KVA