Help with Single Phase PE Sample Question

[wfg42438]

hello,
In the sample question below the drop across the 1-Phase Cable is considered twice.



I cant recall why this has to be done can someone please refresh my memory?

 

[akyip]

hello,
In the sample question below the drop across the 1-Phase Cable is considered twice.
View attachment 27075
View attachment 27074

I cant recall why this has to be done can someone please refresh my memory?

Because for 1-phase circuits, there is current going both to the load (through the supply/hot conductor) and then back to the source (through the neutral conductor). So both conductors have a voltage drop because of the current (V = IZ).

In a balanced 3-phase circuit, only the supply/hot conductor sees a voltage drop. The neutral conductor in a balanced 3-phase current has zero current because the phasor sum of the currents from 3 balanced phases is zero.

 

[wfg42438]

Thanks akyip!