3 Phase Motor HP Calculation Formula

3 Phase Motor HP Formula:

\[ HP = \frac{V \times I \times \sqrt{3} \times PF \times Eff}{746} \]

Voltage (V):

volts

Current (I):

amps

Power Factor (PF):

(dimensionless)

Efficiency (Eff):

(dimensionless)

Horsepower (HP):

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1. What is the 3 Phase Motor HP Formula?

The 3 Phase Motor HP Formula calculates the horsepower output of a three-phase electric motor based on electrical input parameters. It provides an accurate assessment of mechanical power output from electrical power input.

2. How Does the Calculator Work?

The calculator uses the 3 phase motor HP formula:

\[ HP = \frac{V \times I \times \sqrt{3} \times PF \times Eff}{746} \]

Where:

\( V \) — Voltage (volts)
\( I \) — Current (amps)
\( \sqrt{3} \) — Square root of 3 (approximately 1.732)
\( PF \) — Power factor (dimensionless)
\( Eff \) — Efficiency (dimensionless)
\( 746 \) — Conversion factor (watts to horsepower)

Explanation: The formula converts electrical power (in watts) to mechanical power (in horsepower) while accounting for three-phase power characteristics and system losses.

3. Importance of HP Calculation

Details: Accurate horsepower calculation is crucial for motor selection, system design, energy efficiency analysis, and proper sizing of electrical components and mechanical loads.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, power factor (0-1), and efficiency (0-1). All values must be positive numbers within their respective valid ranges.

5. Frequently Asked Questions (FAQ)

Q1: Why is √3 used in the formula?
A: √3 accounts for the phase relationship in three-phase power systems, converting line-to-line voltage to phase voltage.

Q2: What are typical power factor values?
A: Power factor typically ranges from 0.8 to 0.95 for most industrial motors, with higher values indicating better power quality.

Q3: How does efficiency affect the calculation?
A: Efficiency represents the ratio of mechanical power output to electrical power input, accounting for losses due to heat, friction, and other factors.

Q4: When should this formula be used?
A: This formula is specifically designed for three-phase AC induction motors operating under balanced load conditions.

Q5: Are there limitations to this calculation?
A: The calculation assumes balanced three-phase power, steady-state operation, and may not account for motor starting currents or variable speed operation.