Three-Phase Current Imbalance Calculator
Calculate average phase current and maximum-deviation current imbalance from three measured readings.
Enter measured or design values
Current imbalance
Screening metric only; no universal equipment acceptance threshold is implied.
About this calculator
Calculate average phase current and maximum-deviation current imbalance from three measured readings.
Use readings taken at the same operating condition. The result is a screening metric and is not a universal motor, transformer, or utility acceptance threshold.
Method and assumptions
Average current is the arithmetic mean of the three phase-current readings. Percent imbalance is the largest absolute deviation from that average divided by the average, multiplied by 100.
Enter values measured or specified for the same load, system, and operating condition. These simplified calculations do not model harmonics, transient behavior, or equipment-specific acceptance limits.
FAQs
Does this result establish compliance or equipment acceptance?
No. It is a calculation or screening metric. Apply the equipment manufacturer criteria, project requirements, and locally applicable standards.
Which voltage readings should I enter?
For the voltage screen, enter all three RMS line-to-line readings measured at the same operating condition and point in the system.
Sources
Power triangle and maximum-deviation definitions as stated in the method above. Confirm manufacturer-specific criteria before applying results.