3-Phase Motor Amperage Calculator
Calculate full load current for 3-phase and single-phase motors with power analysis
Calculate Motor Amperage
Most industrial motors are 3-phase
Line-to-line is most common for motor ratings
Common voltages: 230V, 380V, 480V, 575V
Motor power rating from nameplate
Typical range: 0.80 to 0.98 for 3-phase motors
Typical range: 75% to 95% for industrial motors
Motor Analysis Results
Formula used: I = P / (√3 × V × cos(φ) × η)
Input Power: 0.00 kW | Efficiency: 85% | Power Factor: 0.85
Configuration: 3-phase (line-to-line)
Performance Analysis
Example: 2 HP 3-Phase Motor
Motor Specifications
Power Rating: 2 HP (1.492 kW)
Voltage: 230V (line-to-line)
Power Factor: 0.85
Efficiency: 95%
Configuration: 3-phase
Calculation
I = P / (√3 × V × cos(φ) × η)
I = (2 × 746) / (1.732 × 230 × 0.85 × 0.95)
I = 1492 / (1.732 × 230 × 0.85 × 0.95)
I = 1492 / 321.8 = 4.64 Amperes
Standard Motor Voltages
3-Phase Motor Applications
Industrial pumps and compressors
Manufacturing equipment
HVAC systems
Marine propulsion
Construction equipment
Understanding 3-Phase Motor Calculations
What is a 3-Phase Motor?
A 3-phase motor operates on three-phase alternating current (AC) power. It contains electromagnets that interact to create rotational motion. 3-phase motors are widely used in industrial applications due to their efficiency, reliability, and smooth power delivery.
Why Calculate Amperage?
- •Wire Sizing: Determine proper conductor size
- •Protection: Size circuit breakers and fuses
- •Power Planning: Calculate electrical load
- •Energy Costs: Estimate operating expenses
Calculation Formulas
3-Phase Line-to-Line:
I = P / (√3 × V × cos(φ) × η)
3-Phase Line-to-Neutral:
I = P / (3 × V × cos(φ) × η)
Single-Phase:
I = P / (V × cos(φ) × η)
- I: Current (Amperes)
- P: Power (Watts)
- V: Voltage (Volts)
- cos(φ): Power factor
- η: Efficiency (decimal)
Motor Parameters Explained
Power Factor (cos φ)
- • Ratio of real power to apparent power
- • Range: 0.8 to 0.98 for most motors
- • Higher values indicate better efficiency
- • Affects reactive power consumption
Motor Efficiency (η)
- • Output power ÷ Input power
- • Range: 75% to 95% for industrial motors
- • Higher efficiency reduces operating costs
- • Premium efficiency motors: 90%+