Why Delta Star transformers are used for Lighting loads?

Why Delta Star Transformers are used for Lighting Loads

Distribution Transformer is normally used Delta-Star Connection to get Neutral point as a reference for the neutral line in the secondary Winding of the Transformer and load feeding will be from the phases of the secondary winding with reference for the neutral line and Earthing system.

• For lighting loads, neutral conductor is must and hence the secondary must be star winding and this lighting load is always unbalanced in all three phases.
• To minimize the current unbalance in the primary we use delta winding in the primary So delta / star transformer is used for lighting loads

Delta star Tx provides the Neutral point for the lighting and other single phase loads. So it is possible to evenly distribute the lighting loads among the three phases of the star connection, hence we can avoid overloading a particular phase.

for lighting load we need neutral wire thats why we need this scheme for proper action.

To give exact load Voltage of the unit. Delta Connection to step up the voltage while Star Connection to Step down the Voltage.