Lost Neutral on 3 Phase system - how do you calculate the effect on line voltage

[TwentiethCoffee]

I know the effect of a lost neutral (floating neutral) on a 3 phase system, and the theory of why the line voltages can vary.

However, I have been attempting to show this by calculating the line voltages of a phase system at given loads on each phase.

Lets say:- Red 296 Amps, Yellow 279 Amps and Blue 219 Amps.

How do I take these loads and the known 3phase voltage @ 400V and calculate the individual line voltages in a lost neutral situation?

I hope i'm making sense.

 

[Marvo]

To show the varying line voltages you can plot it as a phasor diagram then use Millmans Theorum to calc the voltages wrt supply neutral. There's other mathematical methods but they can get messy unless you're a bit of a math whizz.

I'll see if I can find a link to an explanation that doesn't go too deep into technicalities.

**edit here's a quick explainer