Voltage Unbalance Calculator

This tool calculates the voltage imbalance for in a 3 phase system. Enter the three line voltage values Va, Vb and Vc.




Voltage unbalance occurs when the three-phase voltages differ in amplitude or are displaced from their normal 120° phase relationship, or both. This is shown in the picture below

Example Calculations

If Va=Vb=Vc, there is no unbalance and the calculator gives 0%.

For the following values:

  • Va=200
  • Vb=205
  • Vc=220

The average voltage is 208.33 V. The max deviation is 11.67 Volt and the voltage imbalance is 5.60%.

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