How to convert electric current in amps (A) to apparent power in kilovolt-amps (kVA).
You can calculate kilovolt-amps from amps and volts, but you can't convert amps to kilovolt-amps since kilovolt-amps and amps units do not measure the same quantity.
The apparent power S in kilovolt-amps is equal to phase current I in amps, times the RMS voltage V in volts, divided by 1000:
S(kVA) = I(A) × V(V) / 1000
So kilovolt-amps are equal to amps times volts divided by 1000.
kilovolt-amps = amps × volts / 1000
or
kVA = A ⋅ V / 1000
What is the apparent power in kVA when the phase current is 12A and the RMS voltage supply is 110V?
Solution:
S = 12A × 110V / 1000 = 1.32kVA
The apparent power S in kilovolt-amps (with balanced loads) is equal to square root of 3 times the phase current I in amps, times the line to line RMS voltage VL-L in volts, divided by 1000:
S(kVA) = √3 × I(A) × VL-L(V) / 1000
So kilovolt-amps are equal to √3 times amps times volts divided by 1000.
kilovolt-amps = √3 × amps × volts / 1000
or
kVA = √3 × A ⋅ V / 1000
What is the apparent power in kVA when the phase current is 12A and the line to line RMS voltage supply is 190V?
Solution:
S = √3 × 12A × 190V / 1000 = 3.949kVA
The apparent power S in kilovolt-amps (with balanced loads) is equal to 3 times the phase current I in amps, times the line to neutral RMS voltage VL-N in volts, divided by 1000:
S(kVA) = 3 × I(A) × VL-N(V) / 1000
So kilovolt-amps are equal to 3 times amps times volts divided by 1000.
kilovolt-amps = 3 × amps × volts / 1000
or
kVA = 3 × A ⋅ V / 1000
What is the apparent power in kVA when the phase current is 12A and the line to neutral RMS voltage supply is 120V?
Solution:
S = 3 × 12A × 120V / 1000 = 4.32kVA
