Amps to HP conversion formulas let you calculate the horsepower from known Amps and volts. Let’s first take a look at formulas:
- DC Amps to HP formula: (E * I * %Eff)/746
- Single phase Amps to HP formula: (E * I * %Eff * PF)/746
- Two phase Amps to HP formula: (E * I * %Eff * PF * 2)/746
- Three phase Amps to HP formula: (E * I * %Eff * PF * 1.73)/746
Let’s solve some examples to understand the above defined formulas.
In case of DC
Example: A 24 volt DC motor having an efficiency rating of 90 percent draws a current of 4.318 A. Determine the horsepower.
Solution:
Horsepower (HP)
= (24 * 4.318 * 0.9) / 746
= 0.125 = 1/8 HP
In case of Single Phase AC
Example: A 100-volt single phase AC motor has an efficiency rating of 93% and a power factor of 85%. If the motor draws a current of 4.718 A. Determine the horsepower.
Solution:
Horsepower (HP) = (100 * 4.728 * 0.93 * 0.85) / 746
= 0.5 = 1/2 HP
In case of Three phase AC
Example: A 280-volt three-phase AC motor has an efficiency rating of 88% and a power factor of 80%. If the motor draws a current of 3.8 A. Determine the horsepower.
Solution:
Horsepower (HP) = (280 * 3.8 * 0.88 * 0.8) / 746
= 1 HP