What is a typical application and characteristics of Delta/star 3 phase transformer?

Question

What is a typical application and characteristics of Delta/star 3 phase transformer?

Answer 1

According to my little Engineering Pocket Reference Handbook, a Delta-Wye connection is used for "power and lighting" (meaning motors, heaters, electronic loads, and lighting).  While the Delta-Delta connection can withstand higher unbalanced loads in the secondary, the Delta-Wye needs to have balanced loads.

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Answer 2

Delta-Y for Lighting and Power*

To eliminate the unbalanced primary currents in any one bank, the delta-Y system finds many uses. Here the neutral of the secondary three-phase system is grounded, and the single-phase loads are connected between the different phase wires and the neutral, while the three-phase loads are connected to the phase wires. Thus, the single-phase load can be balanced on three phases in each bank. Secondary voltage will be for 3 phase 4 wire system, 120/208 Y volts or 277/480 Y volts.

Answer 3

In the cases where the neutral is not needed, a 3-phase star/wye/Y implementation (4 wires, which is typically what is available at your plug) can be transformed into a 3-phase delta (3 wire) thus eliminating an unneeded wire.  Usually the component will call for one or the other.

Answer 4

Delta/star is the standard transformer for reducing

utility transmission voltage to 'consumer` voltage.

Answer 5

Delta/Star connection is recommended for Industrial Power systems and Lighting supply. The wye neutral can be grounded easily in order to eliminate the harmful effects of lightning.