These inverters are used for variable speed three phase fans and blowers. For example for controlling speed of side fans for minimum ventilation in environment control poultry houses or controlling speed of blowers/fans in space heaters so that plastic pipe is inflated at a slower rate so the birds are not frightened specially layers on floor or broiler breeders
Available in different wattage starting from 1 Hp down to hundred horse power but in poultry houses generally one horse power is used for side fans during minimum ventilation and three horse power for space heaters.