Star and Delta Connections

Line and phase voltages and currents in star (Y) and delta (Δ) connected systems.

Intermediate

	Star (Y)	Delta (Δ)
Line voltage	$V_L = \sqrt{3}\,V_{ph}$	$V_L = V_{ph}$
Line current	$I_L = I_{ph}$	$I_L = \sqrt{3}\,I_{ph}$
Neutral	available	none

Line voltages lead the corresponding phase voltages by 30° in star. Star connection provides a neutral for single-phase loads; delta suits high-current loads and motors.

Phase sequence (R-Y-B in India) determines the direction a three-phase motor rotates — swap any two lines to reverse it.

Spotted a mistake or want to add detail? Suggest an improvement — Content Contributors' edits are reviewed by editors before they go live.

Discussion (0)