HP to Amps Conversion Chart:
Below table is calculated amps value for the respective standard motor horsepower rating. The table first column indicates the DC current and followed by the AC current. AC current is calculated by the power factor of 0.86 for single-phase supply and 0.8 for three-phase supply.
Look at the table the 1 hp motor takes will be 1.3 A at 440 Volts three-phase at the same time while using single-phase it takes only 3.8 Amps.
Also 5 HP three-phase motor takes 6.4 Amps. In practically the current rating may change and which is based in the manufactured standard as well as the what grade copper they are using to winding the motor.
i.e motor copper grade’s quality will be grade1 > grade 2 > grade 3
7.5 Hp 3-phase motor takes 9.7 Amps, 10 HP, 3 phase motor takes 13 Amps
Look at that, while increasing the horsepower rating the ampere value and motor size also will be increased.
|
Power |
DC amp |
AC Current in Amps |
||
| HP | 110V | 110V | 230V | 440V |
| 1 | 5.1 | 7.9 | 3.8 | 1.3 |
| 1.5 | 7.5 | 11.8 | 5.7 | 1.9 |
| 2 | 10.2 | 15.9 | 7.6 | 2.6 |
| 3 | 14.9 | 23.3 | 11.1 | 3.8 |
| 5 | 25.1 | 39.1 | 18.7 | 6.4 |
| 7.5 | 37.3 | 59.1 | 28.3 | 9.7 |
| 10 | 50.9 | 79.3 | 37.9 | 13.0 |
| 15 | 74.6 | 116.3 | 55.6 | 19.1 |
| 20 | 101.7 | 158.6 | 75.8 | 26.1 |
| 30 | 149.2 | 236.6 | 113.1 | 38.9 |
| 50 | 250.9 | 391.1 | 187.1 | 64.3 |
| 60 | 305.2 | 475.7 | 227.5 | 78.3 |
| 100 | 508.6 | 788.6 | 377.1 | 129.7 |
| 120 | 610.4 | 946.3 | 452.6 | 155.7 |
| 150 | 746.0 | 1182.9 | 565.7 | 194.6 |
| 180 | 895.2 | 1419.5 | 678.9 | 233.5 |
| 200 | 1017.3 | 1577.2 | 754.3 | 259.5 |
| 240 | 1186.8 | 1892.6 | 905.2 | 311.4 |
| 300 | 1492.0 | 2365.8 | 1131.4 | 389.2 |
| 350 | 1695.5 | 2760.0 | 1320.0 | 454.1 |
| 375 | 1898.9 | 2959.8 | 1415.6 | 486.9 |
| 415 | 2102.4 | 3272.6 | 1565.2 | 538.4 |
| 470 | 2373.6 | 3706.3 | 1772.6 | 609.7 |
| 500 | 2543.2 | 3942.9 | 1885.7 | 648.7 |
| 570 | 2848.4 | 4494.9 | 2149.7 | 739.5 |
this is a great chart but why don’t your numbers match up with the NEC?