Types include single or 3 phase input power supply & frequency inverters for high power ratings, ranging from 450HP-2500HP to with line voltage from 380V to 690V are available. Specifications of inverters vary according to model. There are two main types of frequencies to be compared: low frequency vs high frequency inverters. Used in industrial applications including fans, exhausters, pumps, mixers, compressors, extruders, feeders, crushers, separators, process. Weight: Low-frequency inverters are generally heavier than high-frequency inverters, mainly due to their larger and heavier transformers. Low-frequency inverters operate at a frequency of 50 or 60 Hz, which is the same frequency as the AC electricity grid.