* HP to Amps calculator* is used to

**of the motor is known. You can use the Electrical calculator to find the current in single, 2, and 3 phase motor circuits as well as in dc circuits.**

*calculate the amperes from horsepower*Formulas:

List of Contents

## DC (Direct current) Calculations

In DC circuits amps is the ratio between the product of HP * 746 to Voltage times efficiency.

Mathematically:

DC Amps = [HP * 746] / [E * %age Efficiency]

Example: Find the current passing through 24 volt, 1/2 HP motor having an efficiency of 95%.

Solution: Current = [0.5 * 746] / [24 volt * 0.95] = 16.35 Amps

## Single phase AC Calculations

The single phase AC calculations involve the power factor in denomatior of equation.

Mathematical formula:

Single phase Amps = [HP * 746] / [E * %age Efficiency * PF]

Example: Determine the amps in single phase 1 HP, 120-volt motor having an efficiency rating of 88% operating at a power factor 0.9.

Solution: Current = [1 * 746] / [120 * 0.88 * 0.9] = 7.84 Amps

## Two Phase, 4 Wire AC Calculations

The two phase calculations are similar to 1 phase with an additional factor 2 in the denominators.

Mathematical equation:

Two-phase Amps = [HP * 746] / [E * %age Efficiency * PF * 2]

Example: Determine the current flowing through a two-phase, 0.5 HP, 220 volt motor having an efficiency rating of 90% and a power factor of 0.92.

Solution: Current = [0.5 * 746] / [220 * 0.88 * 0.9 * 2] = 1.07 Amps

## Three phase AC

The three-phase ac amps involve HP * 746 in the numerator and 1.73 times PF * Efficiency times voltages in the denominator. The formula is identical to the previous case with the difference of factor 1.73 instead of 2 in the denominator.

Mathematical equation:

Three phase Amps = [HP * 746] / [E * %age Efficiency * PF * 1.73]

Example: Determine the current flowing through a three-phase, 2 HP, 400-volt motor having an efficiency rating of 93% and a power factor of 0.9.

Solution: Current = [2 * 746] / [400 * 0.93 * 0.9 * 1.732] = 2.57 Amps