What is the rating of your capacitor bank at your company.

Answer Posted / sunnysky

The correct method for PFC is to calculate how much correct you need.
If you know the PF and Pd of a motor being used on average, and want to improve to 90%p.f. then compute then angle of PF before and after from theta=cos^-1(PF) then take difference in tan (theta) * Pd

Good to Know:
Important formulas which is used for Power factor improvement calculation as well as used in the above calculation

Power in Watts
kW = kVA x Cosθ
kW = HP x 0.746 or (HP x 0.746) / Efficiency … (HP = Motor Power)
kW = √ ( kVA2– kVAR2)
kW = P = VI Cosθ … (Single Phase)
kW = P =√3x V x I Cosθ … (Three Phase)

Apparent Power in VA
kVA= √(kW2+ kVAR2)
kVA = kW/ Cosθ

Reactive Power in VA
kVAR= √(kVA2– kW2)
kVAR = C x (2 π f V2)

Power factor (from 0.1 to 1)
Power Factor = Cosθ = P / V I … (Single Phase)
Power Factor = Cosθ = P / (√3x V x I) … (Three Phase)
Power Factor = Cosθ = kW / kVA … (Both Single Phase & Three Phase)
Power Factor = Cosθ = R/Z … (Resistance / Impedance)

XC = 1/ (2 π f C) … (XC = Capacitive reactance)
IC = V/ XC … (I = V / R)

Required Capacity of Capacitor in Farads/Microfarads
C = kVAR / (2 π f V2) in microfarad

Required Capacity of Capacitor in kVAR
kVAR = C x (2 π f V2)

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