Why there is no neutral wire in delta connection?
Answer:
Delta connection is a 3-phase system that is generally preferred where neutral conductor is not needed, such as for transmission of high voltage power.
In a delta 3-phase connection, you use 3 power-carrying conductors (generally labeled X, Y, and Z).
One distinct advantage of a Δ-connected system is its lack of a neutral wire. With a Y-connected system, a neutral wire was needed in case one of the phase loads were to fail open (or be turned off), in order to keep the phase voltages at the load from changing.
This is not necessary (or even possible!) in a Δ-connected circuit.The main reason why a Delta connection does not use a neutral wire is because the voltage between any two line conductors is always the same.
This means that the return path for the current is always the same.
By using a ground conductor, the current’s return path is equalized across the three lines, even if the voltage is different between them.