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Conversion Formulas

Electrical Formulas Based on 60 Hz


Parallel Circuits



Series Circuits



Transformer Amperes



Voltage Drop



Code Rules



Constants

ELECTRICAL EQUATIONS & LAWS

Symbolic:

E = VOLTS ~or~ (V = VOLTS)
P = WATTS ~or~ (W = WATTS)
R = OHMS ~or~ (R = RESISTANCE)
I = AMPERES ~or~ (A = AMPERES)
HP = HORSEPOWER
PF = POWER FACTOR
kW = KILOWATTS
kWh = KILOWATT HOUR
VA = VOLT-AMPERES
kVA = KILOVOLT-AMPERES
C = CAPACITANCE
EFF = EFFICIENCY (expressed as a decimal)

DIRECT CURRENT (DC)

AMPS = WATTS ÷ VOLTS or I = P ÷ E A = W ÷ V
WATTS = VOLTS x AMPS or P = E x I W = V x A
VOLTS = WATTS ÷ AMPS or E = P ÷ I V = W ÷ A
HORSEPOWER = (V x A x EFF) ÷ 746
EFFICIENCY = (746 x HP) ÷ (V x A)

AC SINGLE PHASE ~ 1ø

AMPS = WATTS ÷ (VOLTS x PF) or I = P ÷ (E x PF) A = W ÷ (V x PF)
WATTS = VOLTS x AMPS x PF or P = E x I x PF W = V x A x PF
VOLTS = WATTS ÷ AMPS or E = P ÷ I V = W ÷ A
VOLT-AMPS = VOLTS x AMPS or VA = E x I or VA = V x A
HORSEPOWER = (V x A x EFF x PF) ÷ 746
POWERFACTOR = INPUT WATTS ÷ (V x A)
EFFICIENCY = (746 x HP) ÷ (V x A x PF)

AC THREE PHASE ~ 3ø    

AMPS = WATTS ÷ (1.732 x VOLTS x PF) or I = P ÷ (1.732 x E x PF)
WATTS = 1.732 x VOLTS x AMPS x PF or P = 1.732 x E x I x PF
VOLTS = WATTS ÷ AMPS or E = P ÷ I
VOLT-AMPS = 1.732 x VOLTS x AMPS or VA = 1.732 x E x I
HORSEPOWER = (1.732 x V x A x EFF x PF) ÷ 746
POWERFACTOR = INPUT WATTS ÷ (1.732 x V x A)
EFFICIENCY = (746 x HP) ÷ (1.732 x V x A x PF)