3 Phase electric power and load calculation

[immi2663]

hi....
i want to know the formula for calculation of 3 phase load(kva) in real life.i have current load values on 3 phases which are different as 56amp,42amp,40amp. Voltage line to neutral is 220v and line to line is 380v.do i use 3 or root(3) or nothing in the formula.how can i calculate load on one phase and total load on all the three pahses in 3 phase system

 

[magoo2]

It's probably easiest to multiply the line current and the line to neutral voltage. So 56 A * .22 kV = 12.32 kVA. Repeat for the other 2 phases.

 

[alabaza]

Three phase load:

For a balanced wye connected
load only:

P = 1.732 x VL x IL

in your case the load is not balanced so do the loads individually and add them up like magoo2 suggested.

56A x .22kv (phase A) + 42A x .22kv (phase B)+ 40A x .22kv (phase C)


If the load was balanced and the line current for example was 50A

P = 1.732 X 50A X .38kv

 

[VTer]

your total kVA in this case is 30.36

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". – Nikola Tesla

 

[dpc]

P = 1.732 x VL x IL

OK, if we're going to pass out equations, let's try to be accurate. If P = Power, you forgot to account for the power factor. I have enough aggravation with non-EEs on this.

 

[ShooterBoter]

If P = Power,

Well, he/she asked for kVA...so the equation still holds but with wrong term; "P" should be changed to "S".