Hi @Binu-Kuwait
The settings dialog actually shows examples of the different outputs each method would provide depending on the provided inputs.
For both options, inputs are Apparent Load and Power Factor
Option N° 1:
The True Load and Reactive Loads are computed then summed.
Computation details for those two values can be found on this Wikipedia page.
NOTE: Revit uses the term “True Load” instead of “Real load” as in the Wikipedia article.
From those two values, the total Apparent Load and Power Factor are computed.
In detail based on the settings dialog above:
- Load 1
- Apparent Load (S)= 1000VA,
- Power Factor= 0.8
- Trued load (P) is then equal to 0.8 x 1000 = 800.
Based on the Wikipedia article Reactive Load(Q) is equal to P x tan(arctan(Powerfactor)) = 800 x tan(arctan(0.8))= 600.
- Load 2:
- Apparent Load (S)= 1000VA,
- Power Factor= 1
- Reactive Load is then equal to Zero.
From those two values, the total Apparent Load and Power Factor are computed.
- Total True value = 800 + 1000 = 1800
- Reactive Load = 600 + 0 = 600
Finally:
- Total Apparent Load = SQRT(1800² + 600 ²) = 1897.37 VA.
- Total Power factor = 1800 / 1897.37 = 0.9448
Option N°2:
In this case the total is computed by just summing the apparent load values (1000 + 1000 = 2000)
Then True Load values are computed and summed
From that, a power factor is computed.
- Load 1:
- Apparent Load = 1000
- Power factor = 0.8
- True Load = 1000 x 0.8 = 800.
- Load 2
- Apparent Load = 1000
- Power factor = 1
- True Load = 1000.
- Sum of Apparent loads = 2000
- Sum of true Loads = 1800
- Total power factor = 1800/2000 = 0.9
I hope you'll find this explanation helpful.
Best regards
Guillaume Chazal