Current calculation in electrical panel.

[andreimorais]

google translator:

"I am trying to get the correct values ​​of electric current per phase.

Basic settings:

Distribution System: 3 phases 4 wires 127 / 220V

Electric panel unbalanced, 3 poles; Voltage 220V; one column (custom panel table)

Revit 2019.

Circuits:

3 x 220V 5500W Showers

Current calculations (if performed correctly)

i = 5500/220 = 25A, the current is shared in two phases. as it is about three circuits, in a balanced situation we would have:

Corresponding phase 1: 25x2 = 50A

Current F2 = 50A

Current F3 = 50A

REVIT calculates the current per individual circuit perfectly, but it totally misses, changing the calculation method inexplicably, does anyone know a way around this problem? am I doing any incorrect settings?

[fabiosato]

Hello,

Which option of load sum calculation are you using?

It is in the Electrical Settings.

[andreimorais]

Soma de carga aparente

"apparent load sum"

[sragan · Accepted solution]

Revit's calculation is correct.   Voltages on different phases are out of phase or out of time with each other, so they must be added like vectors or phasors.   

5500 W * 3 = 16500 watts.   

16500/ (220* sqrt(3)) = 43.3 amps, the same as Revit calculates