Kindly give the brief explanations for checking 12.5 kvar 440V, 25 KVAR 440V,

Kindly give the brief explanations for checking 12.5 kvar
440V, 25 KVAR 440V, 12.5KVAR 690V, 25 KVAR 690V capacitors
microfarad values. what is the microfarad values for the
above four type of capacitors, and give the formula
explanations briefly. I know F-50HZ, voltage, and capacitor.

Question Posted / vr85kannan

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Kindly give the brief explanations for checking 12.5 kvar 440V, 25 KVAR 440V, 12.5KVAR 690V, 25 KV..

Answer / 7anoter4

1)If this is only 1 capacitor and this is the voltage
between capacitor terminals:

Cap=10^9*Q/(Voltage^2*2*pi*frequency) if Q is in kVAR and
capacity in microFarad.

pi=3.14159

Cap=10^9*12.5/(440^2*2*pi*50)=205.5 mF

2)If this is reactive power of 3 capacitors in Y connection:

Voltage at a single capacitor terminals will be 440/sqrt(3)
=440/1.73=254 V

Reactive power of a single capacitor will be 12.5/3=4.167
kVAR

Then the capacity of a single capacitor will be :

Cap=10^9*4.167/(254^2*2*pi*50)=205.5 mF

3)If this is reactive power of 3 capacitors in Delta
[Triangle] connection:

Voltage at a single capacitor terminals will be 440 V

Then the capacity of a single capacitor will be :

Cap=10^9*4.167/(440^2*2*pi*50)=68.5 mF

If Q=25 kVAR Voltage=440 V then the capacity of a single
capacitor will be :

single and Y=411 microF ; Delta=137

If Q=12.5 kVAR Voltage=690 V then the capacity of a single
capacitor will be :

single and Y= 83.6 microF ; Delta=27.85

If Q=25 kVAR Voltage=690 V then the capacity of a single
capacitor will be :

single and Y= 167 microF ; Delta=55.7 microF