Current Imbalance Calculator: Formula & Example Table

current imbalance calculator

Calculate percentage current imbalance in three-phase systems using % I imb= {(Imax - Iavg) / Iavg} * 100

unbalanced current calculation

The currents that do not sum to equal fundamental values on a three phase system create a current imbalance. It is computed as the current maximum minus average current divided by its average average current times 100 percent.

Formula & Table Summary:

\( \%I_{\text{imb}} = \frac{I_{\text{max}} - I_{\text{avg}}}{I_{\text{avg}}} \times 100 \)

Where: \( I_{\text{max}} \) = maximum current, \( I_{\text{avg}} \) = average current

imbalance percentage calculation

The Current Imbalance Calculator calculates the percentage of the lack of balance of the three-phase currents of an electrical system. Too much imbalance may cause overheating, loss of efficiency, and damage to the motor. The equation measures the highest of the measured phase currents to the average of all three phases. Such measurement is important in motor repair, power quality measurement, and the reliability of the electrical system. A 10% load imbalance is usually problematic in most cases, and it needs immediate attention that can be addressed through load balancing or faulty connections. With the calculation of the imbalance, technicians may avoid expensive idle times and prolong the lifetime of the equipment.

three-phase current imbalance

Phase A (A)	Phase B (A)	Phase C (A)	Iavg (A)	Imax (A)	Imbalance (%)
100	95	90	95	100	5.26
120	115	108	114.33	120	4.96
50	48	42	46.67	50	7.14
200	190	180	190	200	5.26
75	70	65	70	75	7.14

Frequently Asked Questions - current imbalance calculator:

What is current imbalance?

It’s the unequal distribution of current between phases in a three-phase system.

How do you calculate current imbalance?

Subtract the average current from the maximum current, divide by the average, then multiply by 100.

What is the acceptable limit for current imbalance?

Typically less than 10% for most motors and equipment.

Why is current imbalance bad for motors?

It causes overheating, efficiency loss, and can shorten motor life.

What causes current imbalance?

Uneven load distribution, faulty connections, or damaged conductors.

How to fix current imbalance?

Balance loads, repair faulty wiring, or replace damaged components.

Does current imbalance affect voltage?

Yes, it can cause voltage imbalance which further stresses equipment.

How often should current imbalance be checked?

During regular maintenance or if overheating or vibration is observed.

Is current imbalance the same as voltage imbalance?

No, but they are related and often occur together.

What tools measure current imbalance?

Clamp meters, power quality analyzers, and motor testers.

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