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Three Phase Motor Power Formula:
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The three-phase motor power calculation determines the real power output of a three-phase electric motor based on voltage, current, power factor, and efficiency. This is essential for proper motor sizing, energy consumption analysis, and electrical system design.
The calculator uses the three-phase power formula:
Where:
Explanation: The formula accounts for all three phases (√3 factor) and both the power factor (ratio of real to apparent power) and motor efficiency (ratio of mechanical output to electrical input).
Details: Accurate power calculation helps in selecting properly sized motors, determining electrical load requirements, calculating energy costs, and ensuring efficient operation of industrial equipment.
Tips: Enter line-to-line voltage in volts, line current in amps, power factor (typically 0.8-0.95 for motors), and efficiency (typically 0.85-0.95 for industrial motors). All values must be positive numbers.
Q1: What is power factor in a motor?
A: Power factor represents the ratio of real power to apparent power, indicating how effectively current is being converted into useful work. It ranges from 0 to 1, with higher values being better.
Q2: Why is efficiency included in the calculation?
A: Efficiency accounts for energy losses in the motor (heat, friction, etc.). The formula calculates electrical input power, so efficiency converts this to mechanical output power.
Q3: Is this formula for line-to-line or line-to-neutral voltage?
A: The formula uses line-to-line voltage (the voltage between any two phases in a three-phase system).
Q4: How does this differ from single-phase power calculation?
A: Single-phase power is simply V×I×PF×Eff. The three-phase formula includes the √3 factor to account for the three phases.
Q5: What's the typical power factor for motors?
A: Induction motors typically have power factors between 0.8-0.9 at full load, lower at partial loads. Synchronous motors can achieve 1.0 or even leading power factors.