Delta Connections
Calculation of Capacitor Unbalance

The leg currents will then become:

Using Kirchoff's Law:

or

Note that 111.3 amps times = approximately192.6 amps. This confirms the fact that in a balanced delta-connected load, the line voltage and phase voltage are equal, and the line current is times larger than the phase current.

This arduous method is simplified by mathematics if the displacement of the currents is not considered and only the integer co-factor is considered. This is simply:

In our case, it would be:

Line current is

Leg current is

But the main concern is the unbalanced delta. What happens to the line and leg currents? The above calculation will not apply. Again, in order to appreciate the mathematics, we will go through the pains of the total calculations.

The phase currents need to be computed and then Kirchoff's current law applied at the junctions to obtain the three line currents. The line currents will not be equal nor will they have a 120° difference as in a balanced load.

Assume we lose a unit in leg A-B:

Let
   V = 7200V
   AB = 600 kvar
   BC = 800 kvar
   CA = 800 kvar

Again, using or C (in mfd) = and

We find

(See Figure 4)

Then:

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