Basic Electric Power Formula in AC And DC Load.

Basic Electric Power Formula in AC And DC Circuits

Power Formulas in DC Circuits 

P = V x I
P = I2 x R
P = V2 / R

Power Formulas in Single Phase AC Circuits

P = V x I x Cos Ф
P = I2 x R x Cos Ф
P = V2 / R (Cos Ф)

Power Formulas in Three Phase AC Circuits

P = √3 x VL x IL x Cos Ф
P = 3 x VPh x IPh x Cos Ф
P = 3 x I2 x R x Cos Ф
P = 3 (V2 / R) x Cos Ф

Where:

P = Power in Watts
V = Voltage in Volts
I = Current in Amperes
R = Resistance in Ohms (Ω)
Cos Ф = Power Factor

Alternative formula

Formula: 

For Single Phase 

P = V × I × cos(θ) 

V = P / (I × cos(θ) 

I = P / (V × cos(θ) 

For Three Phase 

P = √3 × V × I × cos(θ) 

V = P / (3 × I × cos(θ) 

I = P / (3 × V × cos(θ) 

Where, 

P = Power 

θ = Power Factor Angle 

V = Voltage I = Current