Balanced Three-Phase Load

Application

This circuit shows a three-wire delta source powering three equal resistive loads. The grounded load neutral provides a simulator reference without adding a neutral connection to the source.

Schematic Organization

L1, L2, and L3 flow left to right through three matching 1 kOhm resistors. The returns meet at one neutral junction, and each phase has a separate voltage probe.

Expected Behavior

The three probe traces have equal amplitude and are separated by 120 degrees. The source is set to 120 V RMS line-to-line, so a balanced wye load sees approximately 69.3 V RMS from each line to the grounded load neutral.

Key Values

• Line-to-line source voltage: 120 V RMS.
• Frequency: 60 Hz.
• Load: three matched 1 kOhm resistors.

Suggested Experiments

Change all three resistors together to vary balanced load current, then change one resistor to observe the effect of an unbalanced load. Adjust frequency or source voltage and compare all three traces.

Featured Component

V1 is the Three Phase Delta Source. Its L1, L2, and L3 terminals provide the balanced three-wire supply.