Ohm’s law:
V = I × R
I = V ÷ R
R = V ÷ I
Single-phase AC power:
P (watts) = V (volts) × I (amps) × Power factor
Three-phase AC power:
P 3 ∅ (watts) = V (volts) × I (amps) × Power factor × 1.732
Power factor:
PF = cosine (phase angle) × 100
PF = Power (watts) ÷ [ V (volts) × I (amps)]
PF = Real Power (watts) ÷ Apparent Power (VA)
Apparent power:
Apparent Power (VA) = V (volts) × I (amps)
Peak voltage:
V peak = V rms × 1.414
RMS voltage:
V rms = V peak × 0.7071
Inductive reactance:
X L (ohms) = 2 π ƒ L
where X L is the inductive reactance, π is pi (3.14), ƒ is the frequency in hertz, and L is the inductance in henrys