Volts, Watts, AMPS, KVA, KW and Horse Power Conversions
It is not really a conversion as such but a formula where any two values are needed to be known to enable the third to be calculated.
Convert Watts to Volts:
Voltage = Watts / AMPS
E = P ÷ I
Convert Watts to AMPS:
AMPS = Watts / Voltage
I = P ÷ E
Example:
2,300 WATTS = 2300w divided by 120v = 19.1 AMPS
(for 3 Phase divide by 1.73)
Convert AMPS to Watts:
Watts = Voltage x Amps
P = E x I
Example: 19.1 AMPS multiplied by 120v = 2300 Watts
(for 3 phase multiply by 1.73)
Convert Horse Power to AMPS:
HORSEPOWER= (V x A x EFF)÷746
EFFICIENCY= (746 x HP)÷(V x A)
Multiply Horse Power by 746w (1 HP = 746 Watts)
Find Circuit Voltage and Phase
Example:
30 HP at 480 (3 Phase) - 746 multiplied by 30 = 22380
22380 divided by 480 (3 Phase) = 46.5
46.5 divided by 1.73 = 29.5AMPS
Multiply all the motor loads by 1.50% and go to the next circuit size.
Convert KVA to AMPS:
Multiply KVA by 1000/voltage
Example:
30 KVA multiplied by 1000v = 30,000 Watts
30,000 Watts divided by 480 = 62.5 AMPS
(for 3 phase divide by 1.73)
Convert KW to AMPS:
Multiply KW by 1000/voltage and then by power factor
Example:
30KW multiplied by 1000v = 30,000
30,000 divided by 480 = 62.5 x .90 = 56.25amps
(for 3 phase divide by 1.73)
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)
