What will occur if the neutral wire is not connected to earth at distribution substations?

The neutral grounding has many advantages.

1. Provides protection to the person :- If the secondary winding comes in conatct with the body of transformer. A person Touching acciedently the body of transformer (having No neutral Grounding) receives fault shock.

2. Provides protection to Transformers from internal faults:-  if due to internal faults the primary wimding comes in contact with the secondary winding of transformer (without Neutral Grounding) a very high voltage is imposed between the secondary conductor and ground. this would immediately puncture 230V insulation causing massive flashover. This flashover may occur anywhere on the secondary network, Possible inside home or factor, this may produce grave accidents.