Useful Formulas

 

Formulas For Electrical Motors:

To Find: Direct Current Single Phase Three Phase Horse Power E x I x EFF 746 E x I x EFF x PE 746 1.732 x E  x I x EFF x PF 746 Current 746 x HP E x EFF 746 x HP E x EFF x PF 746 x HP 1.732 x E x EFF x PF Efficiency 746 x HP E x I 746 x HP E x I x PF 746 x HP 1.732 x E x I x PF Power Factor --------- Input Watts E x I Input Watts 1.732 x E x I

E     =  Volts                        HP = Horsepower            PF = Power Factor (decimal)                                      EFF = Efficiency (decimal)    I    = Amperes

Formulas For Electrical Circuits:

To Find: Direct  Current Single Phase Three Phase Amperes Watts Volts Watts Volts x Power Factor Watts 1.732 x Volts x Power Factor   -------------------- Volts x Amperes Amperes 1.732 x Volts x Amperes Watts Volts x Amperes Volts x Amperes x Power Factor 1.732 x Volts x Amperes x Power Factor

OHMS Law Capacitance in Microfarads at 60 HZ. Ohms = Volts/Amps (R=E/I) Amps = Volts/Ohms (I=E/R) Volts  = Amps x Ohms (E=IR) Capacitance = 2650 x Amperes                                 Volts Capacitance = 2.65 x kVAR                           (Volts) squared