Hi guys, I have a project I have hit a snag with. I have an AE 333Nx inverter I am tying to 3 phase 4 wire wye grounded gear. The inverter manufacturer is telling me I have a 3 phase grounded wye output from the inverter. There is no neutral coming off the inverter though. I am being asked by the customer to put in an isolation transformer. So then I need a wye-wye 480-480 transformer? At this point I am still trying to understand why I need the transformer and what kind. Any help would be much appreciated. If anyone needs more information just ask. Thanks.