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HP를 암페어로 계산기

필요한 전류 소모량을 확인하려면 모터의 마력 정격과 효율을 입력하세요. 모터 스타터, 접촉기, 보호 차단기의 사이징에 필수적입니다.

모터 부하 분석

기계적 마력 → 전류

소수점
2
계산된 전류 소모량
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A

모터에 필요한 전부하 전류(FLA) 요구량입니다.

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—

변환 공식

1기계적 마력은 정확히 746와트와 같으며, 이는 모든 HP-암페어 변환의 기초입니다.

직류 모터
I = (HP × 746) ÷ (V × Eff)

효율(Eff)은 모터 손실을 반영합니다. 90% 효율의 모터는 HP 출력이 암시하는 것보다 더 많은 전류를 소모합니다.

1상 AC 모터
I = (HP × 746) ÷ (V × Eff × PF)

교류 모터는 효율성 외에도 역률이 필요하며, 둘 다 입력 전류 대비 유효 전력 공급을 감소시킵니다.

3상 AC 모터
I = (HP × 746) ÷ (√3 × V × Eff × PF)

삼상 모터는 전류를 세 개의 상에 분배합니다. √3 계수(1.732)는 선간 전압 관계를 반영합니다.

How to Convert Horsepower to Amps

Horsepower (HP) is a mechanical power rating used to describe motor output capacity. To find the electrical current (amps) a motor draws from the supply, you need to account for the mechanical-to-electrical conversion constant (746 W/HP), the motor's efficiency, and — for AC motors — the power factor. This calculation is essential for sizing motor starters, circuit breakers, cables, and variable frequency drives (VFDs).

Why 746 Watts Per Horsepower?

One mechanical horsepower is defined as exactly 550 foot-pounds per second, which converts to 745.7 watts. This constant is the universal bridge between mechanical and electrical motor ratings. Electric motors are rated in both HP (output) and kW (input), with the difference representing heat losses in the motor windings and core.

Motor Nameplate Data You'll Need

  • HP Rating: The mechanical output power the motor is designed to deliver at full load.
  • Voltage (V): The supply voltage the motor is designed for — often listed as dual voltage (e.g., 230/460V).
  • Efficiency (η): Found on the nameplate as a percentage. Premium-efficiency motors typically run 90–96%.
  • Power Factor (PF): Listed on the nameplate or in the datasheet. Induction motors typically have PF of 0.80–0.92 at full load.
  • Full Load Amps (FLA): The nameplate should also list FLA directly — cross-check your calculated value against this number.

Step-by-Step Conversion

  1. Read the HP: Use the motor's rated output horsepower from the nameplate.
  2. Multiply by 746: Convert HP to watts (1 HP = 746W).
  3. Divide by Voltage: Include the √3 factor for three-phase line voltage.
  4. Apply Efficiency: Divide by motor efficiency as a decimal (e.g., 0.90 for 90%).
  5. Apply Power Factor (AC): Divide by PF for AC motors.
  6. Size Protection at 125%: NEC requires motor branch-circuit conductors rated at 125% of FLA for continuous operation.