3 Phase Motor Power Calculator Price

3-Phase Power Formula:

\[ P = \sqrt{3} \times V \times I \times PF \]

Voltage (V):

volts

Current (I):

amps

Power Factor (PF):

(0-1)

Electricity Rate:

$/kWh

Operating Hours:

hours/day

Power Output:

Daily Energy Cost:

Annual Energy Cost:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is 3-Phase Power Calculation?

The 3-phase power calculation determines the real power consumed by a three-phase motor or electrical system. It considers voltage, current, and power factor to provide accurate power measurements essential for electrical design and cost estimation.

2. How Does the Calculator Work?

The calculator uses the 3-phase power formula:

\[ P = \sqrt{3} \times V \times I \times PF \]

Where:

$ P $ — Power in watts
$ V $ — Line-to-line voltage in volts
$ I $ — Current in amps
$ PF $ — Power factor (0-1)
$ \sqrt{3} $ — Constant for 3-phase systems (≈1.732)

Explanation: The formula calculates real power (as opposed to apparent power) by accounting for the phase difference between voltage and current.

3. Importance of Power Factor

Details: Power factor represents the efficiency of power usage. A low PF (below 0.85) indicates poor electrical efficiency and may result in utility penalties. Industrial motors typically have PFs between 0.85-0.95.

4. Using the Calculator

Tips:

Measure voltage between any two phases (line-to-line)
Use current reading from one phase
Typical power factor for motors: 0.85 (default value)
Average electricity rate: $0.12/kWh (US average)

5. Frequently Asked Questions (FAQ)

Q1: Why is √3 used in 3-phase calculations?
A: It accounts for the 120° phase difference between the three phases in a balanced system.

Q2: How does power factor affect motor costs?
A: Lower PF increases current draw for the same power output, leading to higher I²R losses and increased energy costs.

Q3: What's the difference between line and phase voltage?
A: Line voltage is between two phases, while phase voltage is between a phase and neutral. In star systems, line voltage = √3 × phase voltage.

Q4: How can I improve power factor?
A: Use power factor correction capacitors, avoid motor over-sizing, and maintain equipment properly.

Q5: Why calculate annual energy cost?
A: It helps evaluate motor efficiency investments - a more efficient motor may have higher upfront cost but lower lifetime operating costs.