1. What is Full Load Current of 3 Phase Motor?

Definition: This calculator estimates the full load current (FLC) of a three-phase AC motor based on its power rating, operating voltage, and power factor.

Purpose: It helps electricians and engineers determine the current draw of a motor for proper circuit sizing and protection.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I \) — Full load current (amps)
• \( P_{kW} \) — Motor power (kilowatts)
• \( V \) — Operating voltage (volts)
• \( PF \) — Power factor (0 to 1)

Explanation: The formula converts kW to watts (×1000), accounts for three-phase power (√3), and adjusts for the power factor which represents the phase difference between voltage and current.

3. Importance of Full Load Current Calculation

Details: Accurate FLC calculation ensures proper selection of circuit breakers, wiring, overload protection, and prevents equipment damage or fire hazards.

4. Using the Calculator

Tips: Enter the motor power in kW, operating voltage (default 400V), and power factor (default 0.8). All values must be > 0, with PF between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical power factor for motors?
A: Most induction motors have a PF between 0.8-0.9 at full load, lower at partial loads.

Q2: Why is voltage important in this calculation?
A: Current is inversely proportional to voltage - higher voltage systems draw less current for the same power.

Q3: How does this differ from single-phase current calculation?
A: Single-phase uses I = P/(V×PF) without the √3 factor needed for three-phase systems.

Q4: Should I use nameplate values or measured values?
A: For design, use nameplate values. For troubleshooting, use measured values.

Q5: Does this account for motor efficiency?
A: No, this is the input current. For output power, you'd need to include efficiency in the calculation.