We have a 2000kVA 11kV/415V transformer(DYn- neutral solidly earthed) for our station supply and a 2000kVA 415V Diesel Generator(Star wdg - neutral solidly earthed). Both are connected to one LT Switchboard which is 4 wire. We have a requirement of running both the transformer and DG in parallel sharing the load. The DG Breaker connecting to the switchboard is 4 pole. All other breakers are three pole with solid neutral connections. Is it required that the DG neutral should be isolated from earth when both are running in parallel? What are the risks involved?