3 Phase Balance Delta System - 30 Degree Phase Shift for Apparent Power

[BatmanisWatching1987]

With Problem 111
I solved it by using the following formula
S = √3∠-30*V_L*I_L* = √3∠-30 * (12.5∠0kV) * (70∠20) = 1515.54∠-10.

But in the other problem posted, why isn't there a 30 Degree Phase shift as well.

They are both 3 Phase Balanced Delta Loads.

 

[mivey]

View attachment 22427View attachment 22428View attachment 22429

With Problem 111
I solved it by using the following formula
S = √3∠-30*V_L*I_L* = √3∠-30 * (12.5∠0kV) * (70∠20) = 1515.54∠-10.

But in the other problem posted, why isn't there a 30 Degree Phase shift as well.

They are both 3 Phase Balanced Delta Loads.

Where is the rest of the work?

It matters if you are using I_phase vs. I_line.

V_L in the problem is using V_LL voltage (perhaps the L they use is for "load"?). Maybe the I_L is I_phase.

 

[LMAO]

View attachment 22427View attachment 22428View attachment 22429

With Problem 111
I solved it by using the following formula
S = √3∠-30*V_L*I_L* = √3∠-30 * (12.5∠0kV) * (70∠20) = 1515.54∠-10.

But in the other problem posted, why isn't there a 30 Degree Phase shift as well.

They are both 3 Phase Balanced Delta Loads.

I am pretty much sure this question was asked in a different thread and answered. When calculating 3 phase power (reactive, real or apparent) forget about the 30 degree shift between phase and line voltage/current. Only angle that matters is your load impedance angle which in this case is negative arc cos(0.85) = -31.8 = θ

P=3XVφXIφXcos(θ)
Q=3XVφXIφXsin(θ)
S=3XVφXIφ

 

[wvengineer]

View attachment 22427View attachment 22428View attachment 22429

With Problem 111
I solved it by using the following formula
S = √3∠-30*V_L*I_L* = √3∠-30 * (12.5∠0kV) * (70∠20) = 1515.54∠-10.

But in the other problem posted, why isn't there a 30 Degree Phase shift as well.

They are both 3 Phase Balanced Delta Loads.

This isn't at all helpful, but I'm so glad that I don't have to study for the Power PE Exam again! I was doing what you're doing this time last year. Good luck!

 

[BatmanisWatching1987]

Where is the rest of the work?

It matters if you are using I_phase vs. I_line.

V_L in the problem is using V_LL voltage (perhaps the L they use is for "load"?). Maybe the I_L is I_phase.

Here is my solution for Problem 111