If you want to convert from Hp to Amps you only have to use the calculator that we present below. This calculator is based on the Hp to Amps formula .
To complement the calculator, we show how the conversion is carried out step by step , some descriptive examples from Hp to Amperes, the equivalence table , and the most common power factors and efficiencies for motors.
Hp to Amps calculation formula, DC, AC, 3 phase, 2 phase, 1 phase:
- IDC=Direct current.
- IAC1Ø=Current/Ampere 1 phase.
- IAC2Ø=Current/Ampere 2 phase.
- IAC3Ø=Current/Ampere 3 phase.
- H.P=Horsepower.
- VDC=Voltage direct current.
- VL-N=Voltage line to neutral.
- VL-L=Voltage line to line.
- Ef=Efficiency.
- P.F=Power factor.
How to convert Hp to Amp AC 3 phases in only 3 step:
Step 1:
Multiply Hp (Horsepower) by 746. Example, if you have 100 hp multiply by 746 and you get 74600. (100Hpx746 = 74600).
Step 2:
Multiply the AC voltage by the motor efficiency, the power factor and the square root of 3. For example, if the motor is 220Vac, it has an efficiency of 80% and the power factor is 0.9, it must Multiply 220Vdc by 0.8 (80%) by 0.9 by √3 (square root of 3) to obtain 274,35 (220Vdcx0.8×0.9x√3 = 274,35).
Step 3:
Finally divide step 1 and step 2. For example, (100Hpx746) / (220Vdcx0.8×0.9x√3) = 271,9Amps.
How to convert Hp to Amp DC in only 3 step:
Step 1:
Multiply Hp (Horsepower) by 746. Example, if you have 100 hp multiply by 746 and you get 74600. (100Hpx746 = 74600).
Step 2:
Multiply the DC voltage by the efficiency of the motor. For example, if the motor is 220Vdc and has an efficiency of 80%, multiply 220Vdc by 0.8 (80%) to get 176. (220Vdcx0.8=176)
Step 3:
Finally divide step 1 and step 2. For example, (100Hpx746) / (220Vdcx0.8) = 423,86Amps.
Examples of hp to amp conversions:
Example 1:
A mine dredger has a power of 80Hp, AC, 4160V (L-L), three phase, with an efficiency of 84% (0.84) and a power factor of 0.8. How much amperage does this machine have?
Rta: // The first thing to do is multiply the Hp by 746, then you must divide the previous result between the multiplication of the voltage line line, the efficiency, the root of three and the power factor, giving as a result: 12.33 Amps . (80Hpx746) / (4160Vacx0.84 × 0.8x√3)
Example 2:
An air conditioning system has a power of 5.4Hp, three phase, with a voltage line line of 220 Volts, an efficiency of 0.88 and a power factor of 0.9, how much amperage does this equipment have ?.
Rta: // You must multiply 5.4Hp by 746 and then divide the result by multiplying the rest of the variables, as shown below: (5.4Hpx746) / (220Vacx0.88 × 0.9x√3) = 13, 35 Amps.
Example 3:
An industrial blender of 50hp, bifasica, has a line-neutral voltage of 277 Volts, with an efficiency of 90% (0.9) and a power factor of 0.8, which will be the amperage of the blender ?.
Rta: // It’s simple you just have to enter the previous values in the calculator and it will easily give you the result that is: 46.76 Amps.
Hp to Amps conversion chart-table:
| Horsepower | 60 Hz AC Induction Motor – Current Rating Chart | ||||||
| Single Phase – Current rating | Three Phase – Current rating | ||||||
| 115 Volt | 230 Volt | 200 Volt | 230 Volt | 380-415 Volt | 460 Volt | 575 Volt | |
| 1/6 | 4,4 | 2,2 | ~ | ~ | ~ | ~ | |
| 1/4 | 5,8 | 2,9 | ~ | ~ | ~ | ~ | |
| 1/3 | 7,2 | 3,6 | ~ | ~ | ~ | ~ | |
| 1/2 | 9,8 | 4,9 | 2,5 | 2,2 | 1,3 | 1,1 | 0,9 |
| 3/4 | 13,8 | 6,9 | 3,7 | 3,2 | 1,8 | 1,6 | 1,3 |
| 1 | 16,0 | 8,0 | 4,8 | 4,2 | 2,3 | 2,1 | 1,7 |
| 1 1/2 | 20,0 | 10,0 | 6,9 | 6,0 | 3,3 | 3,0 | 2,4 |
| 2 | 24,0 | 12,0 | 7,8 | 6,8 | 4,3 | 3,4 | 2,7 |
| 3 | 34,0 | 17,0 | 11,0 | 9,6 | 6,1 | 4,8 | 3,9 |
| 5 | 56,0 | 28,0 | 17,5 | 15,2 | 9,7 | 7,6 | 6,1 |
| 7 1/2 | 80,0 | 40,0 | 25,0 | 22,0 | 14,0 | 11,0 | 9,0 |
| 10 | 100 | 50,0 | 32,0 | 28,0 | 18,0 | 14,0 | 11,0 |
| 15 | 135 | 68,0 | 48,0 | 42,0 | 27,0 | 21,0 | 17,0 |
| 20 | ~ | 88,0 | 62,0 | 54,0 | 34,0 | 27,0 | 22,0 |
| 25 | ~ | 110 | 78,0 | 68,0 | 43,0 | 34,0 | 27,0 |
| 30 | ~ | 136 | 92,0 | 80,0 | 51,0 | 40,0 | 32,0 |
| 40 | ~ | 176 | 120 | 104 | 66,0 | 52,0 | 41,0 |
| 50 | ~ | 216 | 150 | 130 | 83,0 | 65,0 | 52,0 |
| 60 | ~ | ~ | 177 | 154 | 103 | 77,0 | 62,0 |
| 75 | ~ | ~ | 221 | 192 | 128 | 96,0 | 77,0 |
| 100 | ~ | ~ | 285 | 248 | 165 | 124 | 99,0 |
| 125 | ~ | ~ | 359 | 312 | 208 | 156 | 125 |
| 150 | ~ | ~ | 414 | 360 | 240 | 180 | 144 |
| 175 | ~ | ~ | 475 | 413 | 275 | 207 | 168 |
| 200 | ~ | ~ | 552 | 480 | 320 | 240 | 192 |
| 250 | ~ | ~ | 692 | 602 | 403 | 302 | 242 |
| 300 | ~ | ~ | ~ | ~ | 482 | 361 | 289 |
| 350 | ~ | ~ | ~ | ~ | 560 | 414 | 336 |
| 400 | ~ | ~ | ~ | ~ | 636 | 477 | 382 |
| 450 | ~ | ~ | ~ | ~ | 711 | 515 | 412 |
| 500 | ~ | ~ | ~ | ~ | 786 | 590 | 472 |
The information in this chart was derived from Table 430-148 & 430-150 of the NEC and Table 50.1 of UL standard 508A. The voltages listed are rated motor voltages. The currents listed shall be permitted for system voltage ranges of 110-120, 220-240, 380-415, 440-480 and 550-600 volts.
The full-load current values are for motors running at usual speeds and motors with normal torque characteristics. Motors built for especially low speeds or high torques may have higher full-load currents, and multi-speed motors will have full-load currents varying with speed. In these cases, the nameplate current ratings shall be used.
Caution: The actual motor amps may be higher or lower than the average values listed above. For more reliable motor protection, use the actual motor current as listed on the motor nameplate. Use this table as a guide only.
Full-load motor-running currents in amperes corresponding to various DC horsepower ratings | ||||||||||||
| Horsepower | 90 Volts | 110-120 Volts | 180 Volts | 220-240 Volts | 500 Volts | 550-600 Volts | ||||||
| 1/10 | ~ | 2.0 | ~ | 1.0 | ~ | ~ | ||||||
| 1/8 | ~ | 2.2 | ~ | 1.1 | ~ | ~ | ||||||
| 1/6 1/4a | ~ 4.0 | 2.4 3.1 | ~ 2.0 | 1.2 1.6 | ~ ~ | ~ ~ | ||||||
| 1/3 | 5.2 | 4.1 | 2.6 | 2.0 | ~ | ~ | ||||||
| 1/2 | 6.8 | 5.4 | 3.4 | 2.7 | ~ | ~ | ||||||
| 3/4 | 9.6 | 7.6 | 4.8 | 3.8 | ~ | 1.6 | ||||||
| 1 | 12.2 | 9.5 | 6.1 | 4.7 | ~ | 2.0 | ||||||
| 1-1/2 | ~ | 13.2 | 8.3 | 6.6 | ~ | 2.7 | ||||||
| 2 | ~ | 17 | 10.8 | 8.5 | ~ | 3.6 | ||||||
| 3 | ~ | 25 | 16 | 12.2 | ~ | 5.2 | ||||||
| 5 | ~ | 40 | 27 | 20 | ~ | 8.3 | ||||||
| 7-1/2 | ~ | 58 | ~ | 29 | 13.6 | 12.2 | ||||||
| 10 | ~ | 76 | ~ | 38 | 18 | 16 | ||||||
| 15 | ~ | 110 | ~ | 55 | 27 | 24 | ||||||
| 20 | ~ | 148 | ~ | 72 | 34 | 31 | ||||||
Typical Un-improved Power Factor by Industry:
| Industry | Power Factor |
| Auto Parts | 0.75-0.80 |
| Brewery | 0.75-0.80 |
| Cement | 0.80-0.85 |
| Chemical | 0.65-0.75 |
| Coal Mine | 0.65-0.80 |
| Clothing | 0.35-0.60 |
| Electroplating | 0.65-0.70 |
| Foundry | 0.75-0.80 |
| Forging | 0.70-0.80 |
| Hospital | 0.75-0.80 |
| Machine Manufacturing | 0.60-0.65 |
| Metalworking | 0.65-0.70 |
| Office Building | 0.80-0.90 |
| Oil field Pumping | 0.40-0.60 |
| Paint Manufacturing | 0.65-0.70 |
| Plastic | 0.75-0.80 |
| Stamping | 0.60-0.70 |
| Steel Works | 0.65-0.80 |
| Tool, dies, jigs industry | 0.65-0.75 |
Typical power factor of common household electronics:
| Electronics device | Power Factor |
| Magnavox Projection TV – standby | 0,37 |
| Samsung 70″ 3D Bluray | 0,48 |
| Digital Picture Frame | 0,52 |
| ViewSonic Monitor | 0,5 |
| Dell Monitor | 0,55 |
| Magnavox Projection TV | 0,58 |
| Digital Picture Frame | 0,6 |
| Digital Picture Frame | 0,62 |
| Digital Picture Frame | 0,65 |
| Philips 52″ Projection TV | 0,65 |
| Wii | 0,7 |
| Digital Picture Frame | 0,73 |
| Xbox Kinect | 0,75 |
| Xbox 360 | 0,78 |
| Microwave | 0,9 |
| Sharp Aquos 3D TV | 0,95 |
| PS3 Move | 0,98 |
| Playstation 3 | 0,99 |
| Element 41″ Plasma TV | 0,99 |
| Current large, flat-screen television | 0,96 |
| Windows-mount air conditioner | 0,9 |
| Legacy CRT-Based color television | 0,7 |
| Legacy flat panel computer monitor | 0,64 |
| While-LED lighting fixture | 0,61 |
| Legacy laptop power adapter | 0,55 |
| Laser Printer | 0,5 |
| Incandescent lamps | 1 |
| Fluorescent lamps (uncompensated) | 0,5 |
| Fluorescent lamps (compensated) | 0,93 |
| Discharge lamps | 0,4-0,6 |
Typical Motor Power Factors:
| Power | Speed | Power Factor | ||
| (hp) | (rpm) | 1/2 load | 3/4 load | full load |
| 0 – 5 | 1800 | 0.72 | 0.82 | 0.84 |
| 5 – 20 | 1800 | 0.74 | 0.84 | 0.86 |
| 20 – 100 | 1800 | 0.79 | 0.86 | 0.89 |
| 100 – 300 | 1800 | 0.81 | 0.88 | 0.91 |
Reference // Power Factor in Electrical Energy Management-A. Bhatia, B.E.-2012
Power Factor Requirements for Electronic Loads in California- Brian Fortenbery,2014
http://www.engineeringtoolbox.com
NEMA Design B Electrical Motors Efficiency
Electrical motors constructed according NEMA Design B must meet the efficiencies below.
| Power (hp) | Minimum Nominal Efficiency1) |
|---|---|
| 1 – 4 | 78.8 |
| 5 – 9 | 84.0 |
| 10 – 19 | 85.5 |
| 20 – 49 | 88.5 |
| 50 – 99 | 90.2 |
| 100 – 124 | 91.7 |
| > 125 | 92.4 |
1) NEMA Design B, Single Speed 1200, 1800, 3600 RPM. Open Drip Proof (ODP) or Totally Enclosed Fan Cooled (TEFC) motors 1 hp and larger that operate more than 500 hours per year.
How to use the Hp to Ampere calculator:
The first thing you have to do is enter the Hp you want to convert, then you must choose the type of AC or DC current, it is very important that once you choose the voltage type, be aware of what the table asks for on the left side; then enter the number of phases, this option only applies to the AC current, then you must enter the efficiency.
Continue entering the voltage, at this point it is very important that you verify what is the voltage requested by the calculator (line-line voltage or line-neutral voltage), otherwise the result may not be correct, finally you have to enter the factor of power, if you do not know the latter you can see the most common values.