Voltage transformer primary neutral open circuit

[shadabgorme]

dear friends,

can somebody help me to understand the following qury.

a 3 phase voltage transformer 66kv / 110V :
One end of VT primary is energized with high voltage and second end which normally brings to make neutral point.
What will happen if primary neutral is open?

 

[scottf]

It's potentially a dangerous situation. The voltage on the neutral end of the primary winding can/will rise up to some voltage that could cause the insulation to fail at that point. That could lead to a catastrophic failure.