Appendix 1Useful Formulas

Ohm’s law: V (volts) = I (amps) × R (ohms)

Single-phase AC power = V (volts) × I (amps) × Power factor

Three-phase AC power = V (volts) × I (amps) × Power factor × 1.732

Power factor = cosine (phase angle) × 100

= Power (watts) ÷ [V (volts) × I (amps)]

Apparent power (watts) = V (volts) × I (amps)

Vpeak = Vrms × l.414

Vrms = Vpeak × 0.7071

Inductive reactance = XL (ohms) = 2πfL, where XL is the inductive reactance, π is pi (3.14), f is the frequency in hertz, and L is the inductance in henrys

Capacitive reactance = XC = image, where XC is the capacitive reactance, f is the frequency, and C is the capacitance in farads

Series ...

Get Electricity for the Entertainment Electrician & Technician now with the O’Reilly learning platform.

O’Reilly members experience live online training, plus books, videos, and digital content from nearly 200 publishers.