What is floating Neutral? Can a machine run under this condition?

Floating  neutral is a condition where the neutral point is not grounded to0 potential or Earth. A3 phase machine will run provided it doen't have any neutral connections but single phase machines connected to this system may blow out. It's known as floating because the voltage at neutral point is circulating between the line voltage levels. Hence for single phase machines and3 phase machines with neutral connected the Phase voltage might go to high levels causing the winding/ component to damage. in a TPN4 wire system of Low voltage the Neutral of the transformer should be grounded (connected to earth) properly to ensue that its voltage is kept at0V.